The sixteenth Annual Report of The Wildfowl Trust

Edited by Hugh Boyd Illustrated by Peter Scott

Printed for t h e w i l d f o w l t r u s t by THE BERKSHIRE PRINTING CO. LTD., Reading, Berks., , 1965 The Wildfowl Trust

Patron her m ajesty the queen

President H.R.H. Prince Philip, Duke of Edinburgh, K.G., K.T.

Vice-Presidents Captain R. G. W. Berkeley The Rt. Hon. The Lord Howick o f Glendale, G.C.M.G., K.C.V.O. General Sir Gerald Lathbury, G.C.B., D.s.o., m .b .e . Sir Percy Lister

Trustees His Grace the Duke of Beaufort, k .g ., p .c ., g .c .v .o . The Rt. Hon. the Earl of Mansfield Major R. J. G. Berkeley H. H. Davis H. C. Drayton Hon. Treasurer Guy Benson

Hon. Director Peter Scott, c .b .e ., d .s .c ., l l .d . Council Dr. Bruce Campbell E. A. Maxwell Michael Crichton R. E. M. Pilcher, F.R.C.S. J. O. Death Dr. G. W. Storey Capt. J. A. Fergusson- Miss P. Talbot Ponsonby Cuninghame Sir Landsborough Thomson, J. J. Jamieson C.B., O.B.E., D.SC., LL.D. G. M . JollifFe, F.L.A.s. Major General C.B. K . Miller Jones Wainwright, c.B . Christopher Marler J. P. Williams Invited to attend A. G. Hurrell (Ministry of Council Meetings Education Assessor) ex-officio Finance Committee Guy Benson (Chairman) R. C. P. Hollond Michael Crichton J. J. Jamieson J. O. Death K . Miller Jones H. C. Drayton Miss P. Talbot Ponsonby James Fisher Scientific Sir Landsborough Thomson Prof. R. A. Hinde Advisory {Chairman) R. C. Homes Committee Prof. A. J. Cain Sir Julian Huxley, f .r .s . Dr. Bruce Campbell Dr. L. Harrison Matthews, R. K. Cornwallis F.R.S. Dr. H. D. Crofton R. E. Moreau Dr. J. H. Crook R. E. M. Pilcher Dr. G. M. Dunnet Dr. G. W. Storey Prof. K. R. L. Hall Dr. W. H. Thorpe, f .r .s . Prof. J. E. Harris, f .r .s . Major General C. B. Dr. J. G. Harrison Wainwright Contents

Section I Annual Report 1963-64

REPORT Page 5 17th ANNUAL GENERAL MEETING 7 ACCOUNTS FOR THE YEAR ENDED 31st DECE M BE R , 1963 8 BALANCE SHEET, 31st D ECE M BE R , 1963 10 THE COLLECTIONS 12 THE RESEARCH UNIT 17 Section 2 Year-book for 1964

RESEARCH AND CONSERVATION IN GREAT BRITAIN Trends in the population of British wintering ducks, 1961-64. G. L. Atkinson-Willes and J. C. Frith 21 Lead poisoning in the Slimbridge wildfowl collection, 1959-64 J. V. Beer and P. Stanley 30 Breeding success of White-fronted Geese from the Nenets National Area. Hugh Boyd 34 Brent Geese in western Europe during the winters of 1962-63 and 1963-64. P. J . K . Burton 40 at Borough Fen Decoy 1964. W. A . Cook 44 The assessment by grazing trial of damage to grass. Janet Kear 46 The reaction of captive Mallard to grain treated with a commercial repellent. Janet Kear 47 Wader ringing by the Wildfowl Trust, 1959-64. M. A. Ogilvie 48 Nests and of Greylag Geese in Galloway. J. G. Young 54 Organic chlorine insecticide residues in Goosanders and Red-breasted Mergan­ sers. C. H. Walker and D. H. Mills 56 The display flights of Shelduck. John Hori 58 RESEARCH AND CONSERVATION OVERSEAS Wildfowl and wildfowling in Bulgaria. Nikolai Boev 58 Breeding of the on the Anser and Glennie Islands, . D. F. Dorward and G. M. Pizzey 64 The ecology and numbers of aquatic birds on the Kafue Flats, Zambia. R. J. Dowsett and A. ds Vos 67 Observations on some aberrant Australian . Paid A. Johnsgard 73 Returns from Steller’s Eiders banded in Izembek Bay, Alaska. Robert D. Jones, Jr. 83 The prospects for wild geese in the Netherlands. T. Lekret 85 Spacing and chasing in breeding ducks. D. F. McKinney 92 Breeding success of geese in west Spitsbergen 1964 M . Norderhaug, M. A. Ogilvie and R .J. F. Taylor 106 The numbers of waterfowl in Estonia. SvennOnno 110 The nesting and some other habits of Alopochen, Nettapus, Plectropterus and Sarkidiomis. Captain C. R. S. Pitman 115 White-headed Ducks in West Pakistan. Christopher Savage 121 Wildfowl Survey in south-west Asia: a progress report. Christopher Savage 123 The geese of Wrangel Island. S. M. Uspenski 126 Shinhama - the Imperial Duck Decoy Peter Scott. 129 REVIEWS 131 Section 1 Annual Report 1963-64

Council and Committees move the Acrow Tower to a new vantage The Officers, Council and Committees of point, affording a greatly improved view the Trust, as at 31st December, 1964 are of the estuary. The third area is being shown on page 2. Council meetings were developed as a corridor to give visitors held in 1963 on 15th January, 19th March, access to observation hides without the 14th May and 6th October. The Finance necessity of an escort. Early in the year the Committee met on 25th February, 29th Curator’s staff constructed a water garden September and 8th December. The annual on the slopes of the Tump and in the meeting of the Scientific Advisory Com­ summer the new heated aviaries ana mittee was held on 19th March. the new rearing area at the far end of the. Rushy Pen were completed with a new Annual General Meeting and Dinner observation post giving views of the sur­ The Seventeenth Annual General Meeting rounding fields. The House Pond in the was held at the Royal Society of Arts on Rushy Pen was enlarged by the creation of 14th May, and the Annual Dinner took an artificial delta. A new pond was exca­ place at the Hyde Park Hotel the same vated in front of the Research Centre and evening. At the dinner The Lord Howick with this pcnd in the foreground a splendid of Glendale, g.c.m .g., k.c.v.o., presided and vista from the windows of the Centre the speakers were Henry Williamson, Peter towards the Acrow Tower was opened up Scott, C.B.E., d.s.c., ll.d ., Norman Collins by some tree felling in the Big Pen. At and Kenneth Harris. The minutes of the Peakirk the Trust acquired an additional Annual General Meeting will be found on 2-15 acres which will be developed in 1965 page 7. as an extension to the grounds. Development The Research Centre In the course of 1964 the Trust was able A notable milestone in 1964 was the con­ to lease three additional small areas at struction of Phase I of a Research Centre, Slimbridge totalling about 2-8 acres. One which was begun in April and nearly of these provided a site for the Research completed by the end of the year. The Centre and another made it possible to upper storey of this first phase of the

ANNUAL REPORT 5 building provides work rooms for the junior prize was won by Gloucester Girls Trust’s Research Unit and a library: the High School by one point from a Beau- ground floor comprises exhibition space desert Park pair. and a lecture room. Although the labora­ tory and museum will have to stay where Borough Fen Decoy they are until we have funds for Phase II, We are again indebted to Mr. and Mrs. we shall immediately have greatly improved R. E. M. Pilcher for opening the duck working conditions for our scientists; in decoy at Borough Fen to visitors on two addition we shall be able to show an days in May. exhibition illustrating the Trust’s work on research and conservation and shall be in a Gosling Party position to expand our educational activi­ ties. The annual party for Gosling members was held on 19th December, 1964. Johnny For this we are indebted primarily to Morris talked and showed films to an The Wolfson Foundation and to The appreciative audience of about 200. Nature Conservancy for grants of £15,000 and £9,500 and to contributors to a special Members’ Collections appeal launched by Mr. H. C. Drayton for this and other development projects, who During the year the following members subscribed altogether £9,710. kindly showed their collections of water­ fowl to fellow members of the Trust: Identification Competition Arthur Cadman, T. Curtis, J. O. Death, The Trust’s third Wildfowl Identification A. W. E. Fletcher, R. Law, Miss E. Competition for Schools was held at the Manasseh, E. A. Maxwell, Mrs. B. New Grounds on 7th March in bitterly Micheli, Mrs. C. Mumford, F. W. cold weather. Sixty-four boys and girls Perowne, R. E. M. Pilcher, G. R. Pryor, from 16 schools took part. Leighton Park G. L. Reid, Shrewsbury School, E. O. again entered several strong teams and had Squire, R. J. Stainsby, Noel Stevens, Mrs. three teams in the first five places in the T. V. Upton, J. P. Williams, D. Wintle. Senior Competition: their A team won the first prize from Monmouth, thus reversing Visitors last year’s result. In the middle age group The fine weather in the summer of 1964 a team from Acklam Hall, who had brought a record total of visitors to the travelled 250 miles from Middlesbrough, Trust’s collections. A comparison with came first with Winchester second. The recent years is shown below. i960 1961 1962 1963 1964 Slimbridge 102,555 151,533 162,030 130,143 151,180 Peakirk 26,531 33*203 30*982 29,434 43*678 129,086 184,736 193,012 159=577 194,85s

Finance In 1964 the Trust’s income provided which can be applied to other development enough revenue for the developments projects and in 1964 the Trust received a mentioned above, with a margin for further generous gift of £5,000 from an anony­ repayment in 1965 of outstanding loans. mous donor for a tropical aviary, which it is On 31st December, 1964, these amounted planned to construct in 1965. to £12,961 and until they are cleared, loan repayment must have first claim on any MEMBERSHIP surplus revenue. Fortunately after com­ There was a further increase in Member­ pleting the Research Centre there will be a ship which passed the 7,000 mark during margin of some £7,000 in the Drayton the year. The figures 011 ist January, 1965, Fund (see under Research Centre above), were: I Jan 62 I Jan 63 I Jan 64 1 Jan 65 Class of Membership Life 298 299 304 316 Full 3360 3423 3584 3644 Associate & Parish 1704 1764 2039 2422 Junior Compounded 6 9 10 12 Gosling 296 285 759 644 Corporate 88 107 101 94 Contributors 34 32 42 38 5786 5919 6839 7170

6 THE WILDFOWL TRUST Obituary Major-General J. M. Kirkman, C.B., The Council learned with sorrow of the C.B.E. death of H.R.H. The Princess Royal on E. N. Kitcat 28th March, 1965. Her Royal Highness M iss J. B. Kitson had been a Member for many years and The Marchioness of Lansdowne visited Slimbridge several times. Hon. Mrs. C. B. Leaf K . C. Lee We record with regret the deaths of the F. H . Lyon following Members and Associates, notified Sir Wilfrid Martineau since the last issue of the Report: Lady Constance Milnes Gaskeli D. W. H. Adams A. Mitchell Lady Addis Major-General H. de R. Morgan, Miss R. E. Andrews D.S.O., D.L. P. Backhouse C. C. Nesling Mrs. M. C. Barnes Mrs. J. M . Norris Mrs. V. C. Batchelor H. H. Norsworthy Brigadier W. Bisset, M.C. Miss C. I. Nott R. Brice-Smith J. N . Oliver Lieutenant-General Sir Frederick R. Perkins Browning, k .b .e., c .b ., d .s.o . G. H. Pickford Miss R. H. Bruce F. A. H. Pitman M rs. H . J. Butt Miss F. Pitt C. Clutsom R. E. Pochin Hon. Mrs. A. Crichton J. G . Pugh Miss B. Y. H. Duncombe P. R. Quayle Lt.-Col. R. T. Foster, d .s.o . Mrs. H. M. Rait Kerr Major J. E. French H. J. Randall, ll.b ., f.s.a. J. C. Frith N. Rathbone E. Giles Mrs. B. M. Richardson M. E. Goodfellow G. Robertson Capt. L. Gregory, o .b .e., r.n . G. W. R. Scudamore Rev. Canon L. W. Grensted E. O. Shebbeare D. B. Grubb Miss M. G. Skipworth F. M. Gurteen S. H. W. Smith Miss M. Hambly-Parker H. A. Söderberg Mrs. M. E. Hamilton Mrs. E. F. Sturt Lt.-Col. R. N. Hardcastle, d .s.o. R. G. Swanton Mrs. L. Haslam W. G. Tinsley Col. H. F. Hilton-Green Miss H. C. Todd S. T. Holland Sir Stanley White, Bart. Capt. P. V. James, r.n . Miss J. M . Wilkins J. A. K ing H. V. Young

Minutes of the Seventeenth Annual General Meeting

1. The Seventeenth Annual General J. O. Death, Esq. Meeting of the Wildfowl Trust was held G. M. Jolliffe, Esq., F .L .A .S . at the Royal Society of Arts, John Adam Christopher Marler, Esq. Street, , W.C.2, on Thursday, E. A. Maxwell, Esq. 14th M ay, 1964, at 5.C0 p.m . K. Miller Jones, Esq. 2. The following Officers and Members R. E. M. Pilcher, Esq., f . r . C . S . of Council, and 36 Members of The Dr. G. W. Storey Wildfowl Trust were present: Miss P. Talbot-Ponsonby Sir Percy Lister, Vice-President J. P. Williams, Esq. Guy Benson, Esq., Hon. Treasurer 3. Apologies for absence were received Peter Scott, Esq., C.B.E., d.s.c., ll.d ., from the following Officers and Members Hon. Director of Council, and 19 Members: Sir Landsborough Thomson, c . b . , H.R.H. The Duke of Edinburgh, K .G ., o . b . e . , Chairman, Scientific Advisory K .T .j Presideiit Committee His Grace the Duke of Beaufort, k . g . , H. H. Davis, Esq. p.c., G.C.V.O., Trustee

ANNUAL REPORT 7 2 9 i i 19649 19649 3 36293 9 6 0 s. 17 16 13 12 16 589 453 455 7 £ 24355 . 1758 • • 3133 15 . . 8906 18 • 7130 • • . 33159

...... INCOME ...... Gate Houses Sales, General Sales, Coloured Key Publications Gate Takings Sales of Surplus Wildfowl Subscriptions, Life Members 420 Subscriptions, Ordinary Income Tax repaidReceipts on fromCovenants Sale of Annual Reports . . 1692 15 Receipts from Annual Dinner Restaurant Donations (including Copper Coin Campaign) New Grounds and Peakirk By General Income:- 7 I — -- 316 350 420 - 1887 1922 8522 34 2726 3866 I 31138 21997 27272 24723 --- 8 8 10

5

s. d. 14

00 £ 00 19208 19208 18 25372 I 5 2 4 0 5 6 5 8 7 3 7 2 3 10 10 II I I 2 9 3 7 9 9 4 4 s. d. II I8 10 0 14 17 17 100 17 —— — 258 563 744 901 383 493 5 427 £ 1535 1360 1603 5828 5934 2789 13 3000 2481 2629 15824 2 10 11736 ...... THE WILDFOWL TRUST, SLIMBRIDGE, GLOUCESTERSHIRE ...... 68018 ...... EXPENDITURE ...... INCOME AND EXPENDITURE ACCOUNT FOR THE YEAR ENDED 31st DECEMBER, 1963 tenance Salaries, Wages and Superannuation Fuel and Power Materials, Repairs and ReplacementsMiscellaneous Gate 2666 Houses 8 Salaries and Superannuation, Administrative Staff . Transport and Mechanical Equipment and Main­ Advertising Food for Wildfowl Salaries, Wages and Superannuation Travelling, Administrative Staff Hostel Upkeep Loan Interest Expenses of Annual Dinner Postages, Telephone and Miscellaneous Expenses . Printing and Stationery Rent, Rates, Water Rates and Insurance 1210 12 New Grounds and Peakirk:- Purchases and Transport of Wildfowl and Eggs Travelling Bank Charges, less Interest earned 308 Printing Annual Report Purchases for re-Sale Royalties Coloured Key Publications Printing 2nd Edition of Coloured Key . 1 To General Expenses 754 760 282 315 234 895 564 49 855 903 698 1788 1665 1 7243 2582 5335 2562 2596 2564 4148 2957 10730 16992 17279 27126 25082

00 THE WILDFOWL TRUST 3 9 3 — I I 6 8 0 8 0 0 0 — ——— — 6535 9445 12938 93236 23299 £9445 £ h 9 00 0 0 0 0 100 310 . . 12000 ...... 5286 those for the yearDecember ended 31st1962 andfor are thegiven purpose ofcomparison TOTAL INCOME FOR THE YEAR Scientific and Educational:- The Nature Conservancy Grant . Donation from Abberton Ringing Station Valuation, 31st December, 1963 Balance, carried down. Donations for Research NOTE.— The figures in the margin are By Duck Adoption By Balance, 31stBalance December, for year 1962to 31st December 1963, brought down . Balance, 31st December, 1963 39 100 315 464 2214 2214 2175 12121 13000 24565 82278 109057 8 8 6 3 3 3 4 ii I 8 0 I 3 7 5 16 ———— 597 816 6535 9445 2175 17748 24565 0 0 81927 10 7000 0 0 ^9445 £ h 2 0 9 0 7 0 il 6 3 4 9 0 4 0 4 l i 162 39 68 ——— 131 1152 . . 1074 . . 3923 . . 11598 • 325 • , , , ...... 252 ...... TOTAL EXPENDITURE FOR THE YEAR Transfer to Accumulated Fund . Capital Expenditure Gate House Extension To Borough Fen Decoy Travel and Miscellaneous Research Expenditure Salaries and Superannuation Valuation, 31st December,Written off 1962Buildings Balance, carried down. Lavatories New Grounds and Peakirk Restaurant Development Equipment New Water Supply Abberton Ringing Station Scientific and Educational Balance, 31st December, 1963 269 15 To Balance, 31st December, 1962 Balance for year to 31st December, 1963 brought down . — — — 198 928 598 362 303 426 1806 1068 1060 3366 9992 4*55 2214 2214 19750 15354 88709 109057

ANNUAL REPORT VO 7 3 15

s. d. 999 £ 7185 10 5 5380 6 3 2613 17 7738 10211 3 23299 0 o £ 5 7 4 2 7 15

7 s. d. 400 0 0 5982 7 7034 o O 2 0 0 0 0 o 13865 o o

11362 13 10

4

ii 800 650 1444 8950 5590 3465

5384 ...... (Market Value £1660) . ASSETS

......

...... a period not exceeding that of the Lease. The Wildfowl Trust (Holdings) Ltd. 1962 Written off in yearDecem ended ber, 31st 1963 . . 597 16 3 Written off to 31st December, Scientific and Educational Sundry Debtors and Payments in Advance Office Equipment Cash at Bankers and Cashin Handon Deposit re Research Centre Fund Gate Houses Valuation (as valued by the Honorary Director) New Grounds and Peakirk Investment at Cost Freehold Properties NOTE.— The New Buildings, etc. to be written off over NOTE.— The Freehold Properties are vestedNew in Buildings, New Amount,Grounds, Slimbridge, 31st December, Gloucestershire 1962 Less for Stock re-Sale Transport Miscellaneous Equipment Hostel and Restaurant Equipment. .

Keys Coloured . Equipment W ild fo w l Amount, 31st December, 1962, at Cost or Valuation 735 450 294 1000 1060 3110 8900 7185 5110 2300 2000 4010 5015 5978 24565 47147 1962 7 ii s. s. d. 15 269 15 £ 1499 I6 9 7924 14512 13 10 10521 7 2 22700 o o £57427 o 34 193 193 8 1534 7000 5072 19 5255 15700 BALANCE SHEET, 31st DECEMBER, 1963

THE WILDFOWL TRUST, SLIMBRIDGE, GLOUCESTERSHIRE .... er.. . year...... LIABILITIES s. d...... We have examined the above Balance Sheet of the Wildfowl Trust dated 31st December, 1963, together with the accompany Income and Expenditure Account and find Donations during count Sundry Creditors Income and Expenditure Account;- Accumulated Fund:- Add Transfer from Income and Expenditure Ac­ Peterborough ProvincialBuilding Benefit Societys- Balance, 31st December, 1962 Interest (Net) received on Deposit per Contra Balance, 31st December, 1962 . Less Repaid during year Research Centre Fund:- Balance, 31st December,Add 1962

L o an s them to be in accordanceSTROUD, with the Books Gloucestershire. and Vouchers produced to us and the information and explanations given to us. S. J. DUDBRIDGE & SONS, 2ist March, 1964 Auditors. 1534 5073 12302 15700 14513 47147 I962 Dr.2175 Balance per Account

THE WILDFOWL TRUST T h e Rt. Hon. the Earl o f Mansfield, to fill these vacancies were elected without J.?., Trustee vote: General Sir Gerald Lathbury, g .c .b ., K. Miller Jones, Esq. d .s .o ., M.B.E., A.D.C., Vice-President R. E. M. Pilcher, Esq., f .r .c .s . Capt. J. A. Fergusson-Cuninghame, Dr. G. W. Storey Council Member Sir Landsborough Thomson, c .b ., James Fisher Esq., Finance Committee O.B.E. Member 9. The proposals for the election of Major General C. B. Wainwright, c .b ., Officers were taken en bloc having been Council Member made by Mr. K. Miller Jones, seconded 4. The Director apologised on behalf of by Sir Kenneth Swan and carried unani­ the Chairman, The Rt. Hon. the Lord mously: H owick of Glendale, G .C .M .G ., k .c .v .o ., President: H.R.H. The Duke of Edin­ who had been unavoidably delayed and burgh, K .G ., K.T. with the consent of the meeting invited Vice-Presidents: Captain R. G. W. the Hon. Treasurer to take the Chair. Berkeley, m .f .h . 5. The Minutes of the Sixteenth Annual The Rt. Hon. The Lord Howick of General Meeting circulated with the Glendale, g .c .m .g ., k . c .v .o . Agenda were amended in paragraph 10 General Sir Gerald Lathbury, g .c .b ., at which Mr. J. O. Death was shown as D.S.O., M.B.E. having seconded the motion re-appoint­ Sir Percy Lister ing the Auditors. The seconder as shown Trustees: His Grace the Duke of in the original minutes was Mr. R. F. Beaufort, k .g ., p .c ., k .c .v .o . Haigh. The Minutes were then accepted The Rt. Hon. The Earl of Mansfield, and signed by the Chairman. J.P. Hon. Director: Peter Scott, Esq., c .b .e ., 6. The Hon. Director gave an account of D.S.C., LL.D. the year’s activities at Slimbridge and Hon. Treasurer: Guy Benson, Esq. Peakirk, after which he moved the adop­ tion of the Report of Council. This was Council’s nominees for election as addi­ seconded by Mr. R. S. R. Fitter and tional Trustees: carried unanimously. John Berkeley, Esq., j .p . 7. The Hon. Treasurer proposed the H . H. Davis, Esq. adoption of the accounts for the year H . C. Drayton, Esq. ending 31st December 1963. The motion 10. The Hon. Treasurer proposed that was seconded by Mr. H. H . D avis and Messrs. S. J. Dudbridge and Sons of carried unanimously. Stroud, Gloucestershire, be re-appointed, Auditors to the Wildfowl Trust for the 8. Dr. James Robertson Justice retired ensuing year pursuant to Rule 19(1). after the Sixteenth Annual General Mr. G. M. Jolliffe seconded the motion, Meeting, and the following elected which was carried unanimously. Councillors retired under Rule 13(1): 11. The business of the meeting was John Berkeley, Esq., j.p. concluded at 5.20 p.m. and followed by H. C. Drayton, Esq. an illustrated talk by Mr. Scott about his Major-General C. B. Wainwright, C.B. recent visit to the Bahamas, and a recent In accordance with Rule 7(6) the follow­ Wildfowl Trust rocket-netting expedi­ ing candidates who had been nominated tion.

ANNUAL REPORT II The Collections in 1964 S. T. JOHNSTONE

In 1963 at Slimbridge and Peakirk over Black-necked Swan (her own were hatched 1,750 swans, ducks and geese were reared by hens) and two under a Black Swan. and some difficulty was experienced in Both hatched a cygnet after 33 days, a disposing of certain species. In con­ seemingly short incubation period (W. sequence it was decided to limit the num­ Banko, i960, The Trumpeter Swan, p. 115, ber of birds reared at Slimbridge in records 33-37 days). The cygnets were 1964 to 1,000 and at Peakirk to 300. These enchanting little things with steely white figures were obtained by non-incubation down and pink bills and tarsi. One has felt of eggs of species with which we had been that Slimbridge was not the most suitable left with a surplus from the previous year, place for breeding swans, but maybe this and limiting certain other kinds by allow­ is not so as Mutes, Bewick’s, Whoopers, ing the parent birds to hatch and rear their Trumpeters, Black, Black-necked and first clutches. 94 kinds were represented in Coscorobas have been reared here. Our the 1,300 birds raised at the two establish­ female Whistling Swan died from an ments, and first breeding records were impaction of the oviduct after building a established for Slimbridge with Crested nest. Screamers, Brown-breasted Whistling It is only in the last three years that we Duck, Whooper Swan, Trumpeter Swan, have added the Anhimidae to our collec­ Patagonian , Bronze-winged tion. At present only the Blacknecked and Duck and Baer’s Pochard, the Bronze­ Crested Screamers Chauna torquata and winged Duck and Patagonian Crested Duck chavaría are represented. The male of the being the first known cases of successful latter had gone sick in the winter so that breeding in captivity. Baer’s Pochard have the first two clutches of eggs laid were been bred previously by Mr. Kooy at Den clear. Through the kindness of the London Helder in Holland. These successes bring Zoo a male was loaned to us and a third the total kinds reared at Slimbridge to 130. clutch of eggs produced two chicks after Other interesting species reared include the parents had incubated for 41 days, quite Magpie Geese, Andean Crested Duck, delightful little things with a spherical head Brown Duck, Hartlaub’s on an equally spherical body. The down Duck, Old World Comb Duck, King Eider is mustard and pepper colour and the and Common Goldeneye. Puna Teal were crown a rich orange, the characteristic again reared successfully at Peakirk. and lores a purplish grey and the The year was a poor one at Slimbridge prominent feet are quite pink. for several species, the Shoveler being The Baer’s Pochard laid nine eggs particularly unsuccessful - no eggs from producing nine ducklings after 27 days of the Cape or New Zealand and clear eggs incubation by a bantam. The ducklings are from the Argentines, even the Common midway in size and colour between the produced only a dozen or so youngsters. Common White-eye and the Australian On the other hand, Peakirk bred Cape and Hardhead, being a greenish brown above New Zealand Shoveler for the first time. with pale yellow underparts. There are six Garganey and Blue-winged Teal failed to yellow blotches on the upper parts, two on produce young. Over 40 Ringed Teal were the rump, two on the thighs and two on the reared in 1963, but in 1964 only a dozen scapulars. The cheeks are yellow and the survived from the 35 hatched, scarcely bill has a pink tip and side, the tarsi are enough to replace winter losses. The Smew black and the eye brown. The ducklings eggs were infertile and no Barrow’s were reared next to a brood of Common Goldeneye hatched. The North American White-eye, and the comparative darkness Ruddy Ducks have not yet recovered from of the latter was most noticeable. the 1962-63 winter, when fifteen breeding pairs were reduced to five. There were few First breeding of the Patagonian nests and not many broods appeared on the Crested Duck ponds and from these about a dozen One of the Patagonian Crested Duck juveniles survived. collected for us by the Sawick Expedition We are particularly pleased to have been laid in October 1963 but the eggs did not successful with the Trumpeter Swans. hatch. In 1964 two females laid and the The female had laid in each of the previous nine ducklings hatched were reared, five two years but on each occasion had deserted by bantams and four by the parent birds. the eggs after partial incubation. We were, Although the adult birds of the two races this time, able to put two eggs under a of Crested Duck are very similar, the

12 THE WILDFOWL TRUST ducklings are quite distinctive. The overall relate, one of the original birds died. colours of the Andean ducklings are brown Eventually we learned that Cologne Zoo and fawn, those of the Patagonian grey and had obtained two males and in December cream. The throat and lower cheeks are 1963 Dr. Windecker the Director of the white, the underparts cream. The cap, Zoo arranged for one of them to be brought neck and back grey, the brown eye situated to Slimbridge. After quarantine the male in the grey area of the head. There are four and our surviving female were installed in cream blotches on the back and the legs the Guinness Aviary. We chose an and bill are pale grey. The eggs are cream enclosure where there were clumps of in colour with an average weight of 55 pampas grass to help the male feel at home. gms and measuring 63 x 46 mm. A Patago­ On 12th February we had the first , and nian and an Andean Crested duckling five were laid in all. They were removed were reared together when one could after five days and placed under a Silky observe the brownness of the marked eye cross bantam. strip and large bill of the latter. The eggs wTere creami sh yellow, the average weight being 75 gms and the size First breeding of the Bronze-winged 70 X 51 mm. Duck Over the years it had been customary The Bronze-winged Duck, Anas specularis, for members of the staff to pick up the which frequents an area including South­ duck at every opportunity, a practice one ern Chile, Argentina and Tierra del Fuego, deprecated for one felt that if ever we is a mallard-sized duck with an overall acquired a male we would find that this mottled brown , a white patch on imprinting on humans would have des­ the cheek and a triangular white chin strap. troyed the bird’s interest in its own kind The speculum, a brilliant bronze, is and that if she did lay the eggs would brighter than that of the Crested Ducks. continue to be infertile. It was therefore There are very few specimens in captivity, all the more surprising that in spite of this the only birds I know of being at the preference for humans three eggs were Wildfowl Trust and at Cologne Zoo. fertile. Two embryos died at an early stage More than ten years ago the well-known but after thirty-one days the remaining Dutch aviculturist, D. G. Schuyl, acquired egg hatched. This long incubation period two birds which were accepted as a pair. suggests that the species may be related to Eggs were obtained and a possible reason the perching ducks (Cairinini) or the for the infertility was suggested to be the shelducks (Tadornini) rather than to the extreme tameness of the birds. Mr. Schuyl dabbling ducks (Anatini). described how they followed him like dogs, The duckling was large and rather and took great delight in being fondled. similar in colouring to a Chiloe Wigeon. It Eventually through his kind co-operation, was dark brown above, the under parts the birds came to Slimbridge in 1955. On being cream. The cap was grey-brown and cloacal examination it was found that both the dark brown eye surrounded with were females. They were released in our reddish brown down. There was a distinct Orchard Pen, an enclosure much fre­ white area on the cheeks and throat. There quented by the visiting public. Both birds were also four white blotches on the back. were delighted to have so many people to The large bill and the tarsus were slate follow round and engage their attention. grey. This predilection for humans was however Apart from a few shrimps, the duckling greatly to their detriment, for they got was not seen to take any food for the first under the visitors’ feet and were con­ three days, and spent most of its time on sequently lamed in a very short time. It the back of its foster-mother. On the was necessary therefore to shut them fourth day, however, it commenced to eat behind a fence in a small enclosure. Here the grated egg and starter crumbs they both proceeded to lay eggs in a clump provided. The bird grew apace, and was of Christmas roses. feathering at three weeks, the white face All sources were now explored with a patch developing at once. view to obtaining a male bird but we could On the dajr the duckling hatched, the find no one in South America who could first egg of a second clutch of five was laid. acquire a male for us. The Savvick expedi­ The duck was allowed to incubate for the tion in 1961 were commissioned to catch first three weeks, when it was found that us some specimens at all costs. This was she had cracked one egg. However, the successfully achieved and four birds were remaining four were fertile. She was given caught and despatched by air. Unfortu­ five Mallard to hatch, which she duly did, nately there were delays in transit, a single but was inclined to neglect them after the bird arrived alive and this, a female, only first few days. Her own eggs, now under a survived a short while. Meanwhile, sad to bantam, hatched again after thirty-one

THE COLLECTIONS IS days., but to our dismay all four ducklings They are now fully grown and in typical had their metatarsi fully flexed. The adult plumage. Their appearance in ‘clenched fist’ effect of the feet persisted for juvenile plumage is shown in a photograph 48 hours but then gradually disappeared on page 5 of illustrations. when the ducklings became quite normal.

Breeding Results 1964: Slimbridge

Date of eggs first incu­ eggs youn¿ egg bated hatched rearec,

Magpie Goose 29.6 24 12 7 Fulvous 10.3 23 20 Southern Red-billed Whistling Duck 10.4 13 12 Northern Red-billed Whistling Duck 3 3 Black Swan 4.2 10 0 Black-necked Swan 13.2 14 12 10 Whooper Swan 13.4 4 3 3 Trumpeter Swan 11.5 4 2 2 Swan Goose 5-4 20 9 6 Russian Bean Goose 23.4 12 II Pink-footed Goose 20.4 7 4 4 White-fronted Goose 11.5 7 0 Greenland White-fronted Goose 20.4 25 4 3 Lesser White-fronted Goose 4-4 22 5 5 Western Greylag Goose 4-4 8 8 Eastern Greylag Goose 10.3 2 2 Bar-headed Goose 15-4 22 7 7 Emperor Goose 23.4 44 21 15 Lesser Snow Goose 17.4 15 15 Greater Snow Goose 20.4 15 13 Ross’s Goose 3-4 16 10 8 Giant Canada Goose 27.3 8 8 Atlantic Canada Goose 17-3 7 5 Alanitoba Canada Goose 23.4 3 0 Taverner’s Canada Goose 6.4 4 2 Dusky Canada Goose 7-4 2 0 Cackling Goose 3.4 8 0 Hawaiian Goose 27.1 72 16 14 Barnacle Goose 23.4 25 20 Black Brant 22.5 13 5 4 Red-breasted Goose 17.6 21 7 7 Cape Shelduck 4-3 4 0 European Shelduck 8.5 8 6 6 Egyptian Goose 24.1 15 14 Abyssinian Blue-winged Goose 8.5 26 8 8 Andean Goose 15-5 14 14 Ashy-headed Goose 2.4 12 10 9 Ruddy-headed Goose 2.4 6 0 Lesser Magellan Goose 10.4 9 8 6 Greater Magellan Goose 13-4 3 0 Cereopsis Goose 1.1 4 2 Andean Crested Duck 2.4 12 4 4 Patagonian Crested Duck 22.2 x8 9 9 Bronze-winged Duck 12.2 10 5 5 Marbled Teal 8.5 30 Cape Teal 19.3 26 16 14 Versicolor Teal 6.3 29 2 i Red-billed Pintail 12.7 3 i i Bahama Pintail 15-5 28 i i i i Chilean Pintail 10.4 13 13 Northern Pintail 9-5 14 14 Kerguelen Pintail 12.5 19 17 Chilean Teal 22.4 6 6 6 Sharp-winged Teal 30.6 12 0 Falcated Teal 18.5 19 6 5

14 THE WILDFOWL TRUST Date of eggs first incu­ eggs young egg bated hatched reared

Australian Grey Teal 1-7 7 6 6 Chestnut Teal 10.3 21 20 19 New Zealand Brown Teal 9.2 26 14 8 Hawaiian Duck 9-3 4 0 Laysan Teal XI.4 73 28 26 North American Black Duck 30.3 7 5 Indian Spotbill 14.4 5 5 4 Chinese Spotbill 4-4 14 14 New Zealand Grey Duck 10.4 i i 10 Australian Black Duck 5-4 3 3 Philippine Duck 20.4 19 17 African Yellowbill 13.3 23 18 Abyssinian Yellowbill 29.3 19 12 i i African Black Duck 19.3 II 6 Gadwall 16.4 30 European Wigeon 31-3 32 32 American Wigeon 10 6 5 Chiloe Wigeon 15-4 15 II Blue-winged Teal 17-5 5 0 Cinnamon Teal 8.5 16 13 7 Garganey 7-5 3 i 0 Red Shoveler 14.5 5 0 Cape Shoveler 10.6 2 0 European Shoveler 17.4 13 12 II Ringed Teal 10.5 62 43 16 European Eider 20.5 14 10 8 King Eider 17.4 10 8 4 Red-crested Pochard 23.2 63 42 32 Rosybiil 2.6 27 13 10 Southern Pochard (hybrid) 28.2 13 4 4 European Pochard 20.5 7 0 Redhead 15-7 23 9 8 Common White-eye 18.S 15 15 Baer’s Pochard 1.6 9 9 8 Australian White-eye 1-5 16 12 New Zealand Scaup 23.4 20 18 Tufted Duck 2 2 Lesser Scaup 30.5 7 4 3 Greater Scaup 21.6 II 2 2 Brazilian Teal 10.5 6 0 Mandarin Duck 14.4 49 38 North American Wood Duck 15-3 102 70 Muscovy Duck 18.4 31 31 Old World Comb Duck 12.6 58 41 28 Hartlaub’s Duck 5.6 10 9 6 Barrow’s Goldeneye 15-5 5 0 European Goldeneye 2-5 7 3 i Smew 15-5 7 0 Red-breasted Merganser 2 North American Ruddy Duck 17-4 12

THE COLLECTIONS 15 Assets”. This set out the arguments lead poisoning from ingested lead shot against ill-considered drainage schemes (p.30). Council Member D r. G . W . Storey and for the wise use of wetlands. The again provided invaluable assistance in the English language version of 14,000 copies preparation and examination of histological was distributed throughout north-western specimens. The researches of workers in Europe to selected people and agencies other institutes, in this country and in directly concerned with agriculture and Finland, were facilitated by the provision drainage. A French version was distributed of specimens for physiological and parasi­ in southern Europe. tological investigation. As usual, prepara­ On the home propaganda front, an tions of heads, skulls, trachea, wángs and exhibition was mounted for the Game complete skins - the latter by our pre- Fair which took place near Stirling, Scot­ parator Mr. Barrow - were made for the land. A good deal of thought and prepara­ ever growing reference collections. These tion went into planning a permanent will be housed in a separate museum room exhibition illustrating the Trust’s work in when the move to the new block is made. conservation and research. This will be We were therefore able to accept gratefully housed in the new research/educational a fine collection of British wildfowl block, the building of which was nearing mounted by Gunn of Norwich and pre­ completion at the year’s end. Fruitful sented by Mr. L. Balfour. liaison was maintained with the Wild- Our links with Bristol University were fowlers’ Association of Great Britain and further strengthened. Mr. R. A. Avery Ireland and a joint publication, a pamphlet continued to utilise parasitological material “Know Your Wildfowl Food Plants”, was from the Collections in his studies for a prepared by Mr. Olney with a view to Ph.D. in the Department of Zoology. The encouraging and facilitating the improve­ Department of Psychology, laying stress on ment of wetland reserves for wildfowl. comparative behaviour studies, was much Supplementing observations of goose interested in the facilities available at Slim­ feeding behaviour, Dr. Kear carried bridge and Dr. Matthews gave courses and through another series of grazing trials seminars to the advanced students of both with tame birds (p.46). Investigation of the Departments. characteristics by which food objects are selected by newly hatched young was Personnel continued and a long-term study of the functional anatomy of the feeding appa­ We were greatly saddened by the sudden ratus in wildfowl begun. Miss C. Furness death of our colleague John Frith at the age joined us on a temporary basis in Septem­ of only 27. Our sympathy must especially ber to prepare the extensive illustrations go to his widow, a bride of six months, needed. and to his unborn heir. Experiments to investigate the north­ Mr. Olney, who came to the Trust in west “nonsense” orientation of Mallards 1956, left in August to take up the new were continued with both the Borough Fen post of Biologist to the Royal Society for and the Slimbridge stocks. Those with the the Protection of Birds. He went with former were aimed at ascertaining the everyone’s good wishes and our anticipa­ importance of learned landmarks by a tion of even closer relations between the lengthy series of releases at short distances two organisations. Mr. Phillips, who had from the Decoy. Visual relays of the flying left following a serious motor cycle accident ducks from one observer to another posted three years before, returned as laboratory to the north-west were successful and gave assistant, when Miss Rebbeck left after promise that it will eventually be possible nine months with us. to determine how long the “nonsense” orientation lasts. The Slimbridge birds were Finance subjected to shifts of their physiological “clocks” and then used to investigate the The Nature Conservancy continued its part played by the moon in orientation. essential support of the research pro­ This was a lengthy and frustrating gramme at the rate of £12,000 p.a. In addi­ business requiring very precise cloud tion the Conservancy, with Treasury conditions seldom occurring and difficult approval, awarded a capital grant (payable to forecast. in the financial year 1965-66) towards the Dr. Beer continued his routine post­ cost of building and equipping one floor of mortem examinations of birds dying in the the new research centre. The Trust is Collections, establishing the relative im­ deeply grateful not only for the actual portance of the various mortality factors money but also for the implicit recogni­ and devising prophylactic measures. A tion of the value of our activities in particularly interesting study was that of research and conservation.

18 THE WILDFOWL TRUST Ringing, 1963-64 ringed 630 Greylag Geese. This was un­ The number of ducks ringed in 1963-64 dertaken to provide a sample of marked was 5472. The reduction from the previous birds in support of the population study season is principally due to a much reduced being made of this species. Mr. J. G. catch of Mallard at Slimbridge. Although Young and helpers caught 21 Greylag the Trust has no intention of ceasing to Geese in Wigtownshire in June 1964. operate the duck decoy at Slimbridge, it has Following the successful round-up of been decided to cut down the catching moulting Canada Geese on the Beauly effort, particularly in the early part of the Firth, Inverness-shire in July 1963, des­ season, a period when very large numbers cribed in the 15th Annual Report, the Hon. o f Mallard have already been ringed in past Douglas N. Weir organised a further years. A striking feature of the catch at operation in July 1964. 93 birds were Abberton by Major General C. B. Wain­ caught of which five had been marked the wright, c .b ., is the high total of Wigeon previous year and three bore rings put on ringed. This is the second highest catch of in Yorkshire, thus adding valuable infor­ this species and comes after a period of mation to the results already obtained several lean years. Borough Fen Decoy, concerning the moult-migration under­ operated by Mr. W. A. Cook, had a slightly taken by these birds. 41 Canada Geese more successful season than last year with were rounded-up at Frampton Gravel Pits, more Mallard caught, but a drop in the Glos., on 16th June 1964. number of Teal. There was no catch of White-fronted Other trapping stations operated in Geese at Slimbridge in 1964. co-operation with the Trust included a Swans new one at Dersingham, Norfolk, where Mr. J. E. A. Lambert made a successful The ringing of Mute Swans in Britain, beginning with 131 Mallard and 8 Wigeon with the Trust paying for the rings, has ringed in collaboration with Mr. W. A. slowed up slightly as an increasingly high Cook. Messrs. C. A. and M. R. Boardman proportion of the population is already caught 37 Mallard at Ludham, Norfolk. marked. 2,303 were ringed in 1963 and the Mr. D. R. Anderson continues to operate total in 1964 will probably have been the duck trapping station at Duddingston smaller. Loch, Midlothian, where he caught 62 Two Whooper Swans were ringed in birds. We are pleased that Mr. W. Murray Dunbartonshire during the winter of of Culterty Field Station, Newburgh, 1963-64. Three Bewick’s Swans were also Aberdeenshire, has restarted duck trapping marked, one at Abberton Reservoir and on the nearby Ythan Estuary where the two at Slimbridge. late Miss E. A. Garden had pioneered in catching, especially diving ducks. We have Waders arranged to receive his results. A full report of a visit paid to Holland in September 1964 to catch waders will be Geese found on p. 48, together with a summary A Trust rocket-netting team spent a fort­ of the results of our five years catching on night in Perthshire in November 1963 and the Wash.

Ducks ringed, 1963-64

Borough Abberton Fen Slimbridge Other Total Total Species Essex Northants Glos stations 1963-64 1962-63

Shelduck 30 _ „ 30 4 Pintail II 5 - 7 42 Teal 1628 200 12 20 i860 2428 Mallard 547 1603 750 300 3200 3478 Gadwall 4 4 I Wigeon 250 I 8 259 49 Garganey 25 25 20 Shoveler 21 IO 21 52 59 Pochard 18 18 15 Tufted 16 I 17 m

2536 1815 792 329 5472 Ó2J 0

RINGING 19 Wild Geese and Swans at the New Crounds, 1963-64

European White-fronted Goose Anser February with a third bird reported on 5th albifrons albifrons. and 8th February. The first seven arrived on 23rd October Barnacle Goose Branta' leucopsis 1963, the latest date ever recorded. The »»»Bar build up during the autumn was also 8 arrived on 18th December 1963 and were remarkably delayed and there were still joined by a ninth on n th January. This is only 32 present on ist December. Num­ the most recorded at one time at the New bers then increased steadily with 2000 at Grounds. They remained until 17th the end of the year and nearly 3000 on 6th January after which date five remained. January. The peak numbers were in late Six were counted on 6th February and February with about 4500 on 23rd. these were last seen in mid-March. Departures began in early March with Dark-bellied Brent Goose Brama ber­ 2100 remaining on 10th. The last seen nicla bernicla were 29 on 24th March. Counts of young birds showed that the Three different individuals of this race breeding season had been only an average were present during January 1964. A single one. The proportion of juveniles in a small bird on 20th February was the last seen. sample in early December was 38-2% with Red-breasted Goose Branta ruficollis an average brood-size of 2.75. These fairly high figures dropped with the big arrivals A fine adult male, the fourth record for the and at the end of January there were New Grounds, appeared on 31st Decem­ 27-4% young, average brood-size 2-5. In ber 1963 and stayed until 8th March. early March a further reduction was Bewick’s Swan Cygnus columbianus be­ recorded to 20-75% young. wickii Lesser White-fronted Goose Anser ery­ The first arrivals were 5 on 17th December thropus 1963. More came during the following A single adult of this species was seen on week and by 30th December there were 26 2nd and 4th February 1964. present. As in previous years the birds were frequently in the pens. During Bean Goose Anser fabalis January and February 1964 numbers Two single birds were seen: an “orange­ remained around 20-25 with a peak of 32 billed” on 26th January and a “dark­ on 31st January. Departures took place in billed” on 8th February 1964. the first half of March leaving a single juvenile which stayed in the pens until Pink-footed Goose Anser brachyrhynchus 22nd April. 28 arrived on 28th September 1963 and there were 42 on 29th, but they left the Whooper Swan Cygnus Cygnus Cygnus same day because of earth-dumping opera­ Three were seen on 28th January 1964 and tions on the Dumbles and did not return. again on 9th February. A single bird was Two were present throughout January and recorded on 15th March.

20 THE WILDFOWL TRUST’ Year Book for 1964

Trends in the population of British wintering ducks

1 9 6 1 - 6 4

G. L. ATKINSON-W ILLES and J. C. FRITH

Summary The data available through the National Wildfowl Counts are used to keep a running check on the numbers of wildfowl occurring in Britain during the winter months from September to March. Each month a brief report is sent to all observers engaged in the investigation, and it is these which provide the basis of the present summary. The species reviewed are Mallard, Teal, Wigeon, Pochard and Tufted Duck and the results are derived from a sample selected from the more important concentration areas. Although referring to the trends apparent in the ten years prior to 1959-60, the discussion centres mainly around the train of events since 1960, and on the effect of the hard weather of early 1963. It is also shown that the autumn counts of dabbling ducks give a good indication of the relative abundance of the species over the winter as a whole, enabling a forecast to be made some four months in advance of the seasonal result. None of the species considered has shown any serious decline as a result of the hard weather of 1963. Mallard continue to increase slowly but steadily. Teal have maintained a more or less constant level since 1949, except for a period of great abundance between 1959 and 1962, which is attributed to events in Holland. The Wigeon population has also remained unchanged, although the numbers are liable to wide fluctuation from year to year. Both Pochard and Tufted Duck have shown substantial increases since 1949, and have also extended the length of their stay in this country. Since 1957 the Tufted Duck population appears to have become more or less stable; the Pochard made its last advance in i960.

The results of the Wildfowl Count investi­ season, 1959-60. In compiling the samples gation for the period 1948-61, and full for these monthly comparisons use has descriptions of the current methods of been made of the records from all places analysis, have already been published by which were covered in both the ‘master5 Eltringham and Atkinson-Willes (1961) and the paired month; the individual and by Atkinson-Willes (1963). The samples vary therefore in bGth size and present paper is concerned therefore with composition, according to the data avail­ recent results, and more especially with able. The resulting indices are nonetheless, events since 1961. This period is one of comparable, each being related to the especial interest because it includes the others through the medium of the master exceptionally cold weather of January and season. They provide the means of detect­ Februar}/ 1963, which is known to have ing annual variations in the population at caused heavy mortality amongst several certain stages of the season, notably during species of ‘wetland’ birds, though not autumn and early winter. apparently amongst the ducks. Of the five T h e seasonal index is compounded from species considered here (Mallard, Teal, monthly results, and describes in a single Wigeon, Pochard and Tufted Duck), none figure the relative abundance of a species has shown signs of disastrous decrease; over the winter as a whole. In compiling; indeed the present populations are mostly the indices only the records from the more above the average level for the past fifteen important areas in Great Britain have been years. considered. These total about 170 in all, As in previous reports the numbers of of which 150 are used by large numbers of ducks counted in each season are presented Mallard, 70 by Teal and Wigeon, 40 by as percentages of the numbers counted Tufted Ducks and 35 by Pochard. In in 1959-60 (i.e. an index of 85 against a practice not more than three-quarters of certain year indicates that only 85 ducks such places are covered on any one of that species were present for every 100 occasion, but despite this the number? of in 1959-60). Two sets of indices are given birds counted represents a substantial for each species : fraction of the estimated British population The monthly indices are obtained by (about 10% in the case o f the dabbling comparing in turn the counts for each ducks, and as much as a quarter of the month of each season with the data for the diving ducks). corresponding months of the ‘master’

TRENDS IN BRITISH DUCKS 21 Mallard Anas platyrhynchos Table I. Monthly indices showing the relative abundance of Mallard in the same months of different years. The figures show the number of birds present in various seasons for every hundred recorded in 1959-60. The figures in brackets are the highest indices obtained in the periods for which an average index only is given. The indices in this table and in Tables II-V should be compared only within the columns, NOT along the rows.

Sep Oct Nov Dec Jan Feb Alar

Average Index 1949-54 66(101) 58(64) 78(83) 91(97) 78(100) 85(98) 85(102) Average Index 1954-59 69(75) 59(74) 88(91) 90(101) 76(82) 94(102) 94(117) Master Year 1959-60 100 100 100 100 100 100 100 Index 1960-61 35 75 103 82 79 87 77 1961-62 114 84 96 131 105 96 102 1962-63 84 68 106 107 74 76 95 1963-64 92 Si 112 101 104 89 91 1964-65 90 78 122 85 95 83 114

F ig u re I. Seasonal indices for Mallard, 1948-1964 (solid line), and the monthly indices for September, October and November combined (broken lines). The similarity between the two readings makes possible a forecast of the seasonal index some four months in advance.

22 THE WILDFOWL TRUST The salient points emerging from Table I population at this time is less liable to are as follows: (a) Since 1959 the level of annual fluctuations than in any other population during the first half of the month. In earlier Novembers the lack of season has been substantially higher than any marked variation from year to year is in either of the two preceding five year indicated by the closeness of the average periods. In February and March, however, indices to the corresponding maxima; the indices have remained virtually un­ more recently the upward trend has been changed since 1949. This suggests that the remarkably smooth except for one rather increase in the early part of the season low result in 1961. Also of interest is the has been due mainly to a larger inflex of striking similarity between the fluctuations immigrants, and that the native stock, in the seasonal indices and those in the early which forms a predominant proportion of part of the season; this making possible the late winter population, has remained a reasonable forecast of the final result at a more or less constant level. while the season is still young (see Figure 1). (6) The results for the autumn of 1963 The practical application of such forecast­ (immediately following the cold winter) ing has yet to be exploited, but with compare favourably with those for 1962; growing confidence it may be possible to moreover the results for February and issue “ early warnings” as much as March 1964 (which provide a partial months before the end of the shooting measure of the resident stock) show no season, should the need arise. For the time significant signs of decrease. If anything being, however, the situation is satis­ there were rather more Mallard in Britain factory: the 2 i% annual increase detected in the season after the cold winter of by Eltringham and Atkinson-Willes (1961) 1962-63 than in the season immediately appears to be continuing, despite the before. rather wider fluctuations of recent years; (c) In most seasons the largest numbers moreover there is no evidence of a con­ of Mallard are counted in November (in trary trend in any of the months under 1964, 56,000 on the selected sample areas); review, implying that all sections of the it is also evident from Table I that the population are at least holding their own.

Teal Anas crecca Table II. Monthly indices to show the relative abundance of Teal in the same months of different years; the figures in brackets are the highest indices obtained in the periods for which an average index only is given.

Sep Oct Nov Dec Jan Feb Mar

Average Index 1949-54 24(32) 36(49) 33(47) 29(40) 83(121) 117(184) 156(245) Average Index 1954-59 28(40) 42(59) 53(69) 46(65) 102(160) 101(118) 123(168) Master Year 1959-60 100 100 100 100 100 100 100 Index 1960-61 88 63 46 30 65 75 91 1961-62 75 85 85 108 110 96 90 1962-63 75 99 92 45 62 53 62 1963-64 93 46 50 37 56 63 67 1964-65 — 56 53 41 77 69 83

As in the other tables, the figures in to a relatively low level, whilst those for the Table II should be compared only within latter part of the winter are somewhat the vertical columns, the fluctuations inflated. This is especially noticeable in the within the horizontal rows being very periods prior to 1959, and in no way largely a reflection of events which took implies a build-up of birds during the place in the master season, 1959-60. Due course of the winter. to exceptional circumstances during that Comparisons within the columns of' autumn the influx of migratory Teal into Table II reveal some striking changes in Britain was very much larger than usual; the behaviour of the immigrant Teal which later on, however, the population returned comprise the great majority of the British to a more normal level, and by March was winter population. During the past 15 noticeably smaller than in previous years. years there has been a marked increase in The indices for 1959-60 being fixed the autumn population, the largest influxes throughout at 100, the corresponding being in 1959, 1961 and 1962. Since then values for the other autumns are reduced the numbers have decreased, the present

TRENDS IN BRITISH DUCKS 23, levels being much the same as those five times the usual level. Compared with attained prior to 1959. Reports from the those for 1958, the 1959 counts (taken Netherlands (Eygenraam 1964) suggest from a sample of 55 waters) showed an that these fluctuations can be attributed to increase o f 8,000 Teal in September, 10,000 various stages in the reclamation of the in October, 16,000 in November and 19,000 Oostflevoland polder at the south-east in December. Of special interest at this comer of the Ijsselmeer. Drainage here time was the recapture in South-east began in 1954 with the closing of the dyke, England of several Teal which had been and by 1958 the water level had been re­ ringed in previous %vinters in the Rhone duced to a depth of a few inches over an delta in southern France; such recoveries area of 125,000 acres. In October of that year were previously unknown, despite inten­ more than 300,000 ducks, mostly Mallard sive trapping in both areas for several and Teal, were counted in the vicinity of years. the dyke alone, and the total number is In i960, the autumn counts were com­ believed to have been upwards o f a million. paratively small, due possibly to the wet­ By the following autumn much of this ness of the season and the great amount of shallow water had been removed, and the floodwater, but in 1961, and again in 1962, polder was able to accommodate less than a much larger numbers than usual were quarter of the previous population. As a present in October and November - the result many of the birds arriving there beginning, it seemed, of a new tradition. were forced to move on, and substantial If this in fact existed, it appears to have numbers came across to England, raising been disrupted by the cold weather of the size of the autumn counts to four or early 1963, which is known to have driven

Figure 2. Seasonal indices for Teal, 1948-1964 (solid line), and the monthly indices for September, October and November combined (broken line). The similarity between the two readings makes possible a forecast of the seasonal index some four months in advance.

24 THE WILDFOWL TRUST large numbers of Teal southwards, back been steadily downwards. In 5-10 years into France and Spain. In the following time the draining of another polder in the autumn (1963) the September counts were south-west comer of the Ijsselmeer may again large for the time of year, but the well result in further large influxes into more important influxes in October and Britain, but in the meantime any large November failed to materialise. In 1964 scale increase seems unlikely. the September counts failed to produce a As with Mallard it is possible to predict realistic index, but the subsequent counts with some confidence the level of the final were similar to those in the previous season. seasonal index from the results of the Reviewing the seasons as a whole (Figure autumn counts. For the past ten years the 2) it will be seen that the present level of pattern described by the two sets of values the indices is well within the range of the has been remarkably similar, the only years prior to 1959, and as such gives no serious divergence being in 1962-63 when cause for alarm; at the same time the the size of the seasonal index was affected optimistic outlook engendered by the years by a marked exodus of birds during the of plenty can no longer be sustained. In all cold winter. In the earlier years, the dis­ probability the big influxes between 1959 parity between the two graph lines is due and 1962 were due to a redistribution of to sudden changes which took place in the the autumn population and not to a general master season; with further changes taking increase throughout Europe. This is to place, a similar disparity is likely to emerge, some extent confirmed by the late winter but this will in no way preclude the counts which show no sign of a comparable possibility of forecasting so long as it increase; indeed the trend at this time has remains constant. Wigeon Anas penelope Table HI. Monthly indices to show the relative abundance of Wigeon in the same months of different years; the figures in brackets are the highest indices obtained in the periods for which an average index only is given. Oct Nov Dec Jan Feb Mar Average Index 1949-54 103(140) 99(119) 74(92) 90(115) 126(155) 92(123) Average Index 1954-59 9I(H 5) 114(144) 77(91) 104(130) 129(184) 97( i5i) Master Year 1959-60 100 100 100 100 100 100 Index 1960-61 87 III 62 104 126 93 1961-62 129 124 120 131 n o 87 1962-63 xoo 101 76 118 X03 50 1963-64 116 65 63 115 72 81 1964-65 121 102 78 79 n o 83 Compared with those for other species, ember comprise only a quarter of the total the Wigeon indices show much wider numbers recorded in the season (compared variation from year to year, and yet over with about a third in the case of Mallard the past 15 years it is evident that the level and Teal), the autumn results are still suffi­ of population has been well maintained, ciently representative to permit a forecast with no significant trend towards increase of the seasonal index. Except in the early or decrease. This is particularly apparent years between 1949 and 1953, when there in the seasonal indices plotted in Figure 3, was no correlation between the autumn but the same may also be deduced from the and seasonal indices, the two sets of values monthly indices. From the latter it is clear are shown to follow the same pattem with that the population in any given month is very fair regularity. That this should be so liable to quite substantial fluctuation, but suggests that weather conditions in mid- at the same time the range of variation has and late winter have much less influence remained more or less constant, and there on the size of the British population than are few months in which any perceptible was at one time supposed. In this respect change has taken place. Since i960 the the results for 1962-63 are of special results for January have perhaps been interest; the similarity between the autumn more consistently high than previously, and seasonal indices (in relation to the and those for March more consistently low, neighbouring years) implying that the but any suggestion of a trend would be pattern for that season was already deter­ premature. The results for December show mined as early as mid-November. T h e rather less variation than those in other cold weather that followed in January and months, and it is often at this time that the February did not apparently bring big largest counts are made. influxes from the Continent (see Table III) Although the numbers of Wigeon nor did it cause a massive exodus. counted in September, October and Nov­

TRENDS IN BRITISH DUCKS 25 F ig u re 3. Seasonal indices for Wigeon, 1948-1964 (solid line), and the monthly indices for September, October and November combined (broken line). The similarity between the two readings makes possible a forecast of the seasonal index some four months in advance.

P o ch a rd Aythya ferina The increase in the numbers of Pochard 1952-53 (although the new level was not is one of the most striking results so far established until two years later); there obtained, the recent level of population was then a period of remarkable stability being almost double that in the early until the second up-surge in 1960-61. As a 1950’s. From the seasonal indices in measure of the two increases, the average Figure 4 it will be seen that these gains level of the indices was 67 in the period have been achieved not by a gradual pro­ 1949 to 1952; from 1954 to 1959-60 it gression but in two distinct upward steps. stood at 95, and from i960 until 1963 at The first of these occurred in the winter of 130. At each stage the individual indices

26 THE WILDFOWL TRUST Table IV. Monthly indices to show the relative abundance of Pochard in the same months of different years.

Oct Nov Dec Jan Feb Mar

Average Index 1949-52 65 79 63 73 79 44 Index 1952-53 210 136 129 65 90 37 Index 1953-54 88 63 56 68 72 62 Average Index 1954-59 m 124 93 84 81 69 Master Year 1959-60 100 100 100 100 100 100 Index 1960-61 1S6 171 115 84 90 76 1961-62 147 221 i n 90 n o 70 1962-63 227 181 124 116 125 105 1963-64 95 i n 112 153 116 150 1964-65 112 176 100 117 120 197

Figure 4. Seasonal indices for Pochard, 1948-1964

TRENDS IN BRITISH DUCKS 27 varied from the mean levels by less than between 1954 and 1959. More recently 15%, and in the middle period by as little the process has been repeated, the second as 5% . up-surge in i960 being due partly to an As with the Tufted Duck, these increases even larger autumn influx and partly to the are attributable in part to a lengthening of upward trend of the mid- and late winter the period during which large numbers of results. birds are present. The effect of this factor Of special interest are the figures for the upon the size of the seasonal index is season 1963-64, the one immediately after clearly shown by the monthly indices in the cold winter. That autumn the numbers the winters of 1952-53 and 1953-54, which were substantially lower than they had been in this case have been excluded from the in the previous three seasons, and for a averages for the early years (see Table IV). time it seemed as though the species had In 1952-53 a very large influx of birds suffered heavy losses. By December, how­ occurred in October, and for the next two ever, the usual numbers had arrived, and months the numbers were well above the for the rest of the winter the level was average for the previous three years. From considerably higher than normal, especi­ January onwards the population was about ally during January and March. In 1964 normal for the time of year (implying that the arrival date was again delayed, but in no fresh immigrants had arrived to aug­ this case only until November. ment the early influx); but because the The reasons for these changes in habit birds had been in the country that much are not yet known, but the answer must longer the seasonal index was raised by presumably lie in northern or eastern more than 60%. In the following year the Europe. From the ringing data it appears autumn influx failed to materialise and the that the British winter population is com­ seasonal index fell back to its former level. posed almost entirely of birds from Ger­ From then on, however, the early arrival many, Poland and Russia ; the native stock date became a regular feature, and this, is small and there is no immigration from together with a general increase over the Iceland, where the Pochard is a recent and winter as a whole, resulted in the plateau still rare invader.

Tufted Duck Aythya fuligula Table V. Monthly indices to show the relative abundance of Tufted D u cks in the same months of different years; the figures in brackets are the highest indices obtained in the periods for which an average index only is given.

Sep Oct Nov Dec Jan Feb Mar

Average Index 1949-54 67(120) 57(74) 84(107) 68(88) 79(H 5) 77(87) Average Index 1954-59 86(116) 55(72) 94(124) 116(144) 77(92) 101(126) 106(114) Master Year 19^9-60 100 100 100 100 100 100 100 Index 1960-61 81 103 137 68 79 118 157 1961-62 119 112 113 76 77 120 112 1962-63 60 73 95 92 96 171 113 1963-64 73 70 97 88 123 94 16S 1964-65 — 60 95 88 73 82 i n

In a previous review of the Tufted Duck monthly results set out in Table V, it (Eltringham and Atkinson-Willes, 1961) appears that both factors are contributory the annual rate of increase over the period in this instance, though the relative import­ 1948-1959/60 was calculated at 8-J-%, a ance of each is not yet clear. result confirmed by independent studies Substantial increases undoubtedly took in both England and Scandinavia (Haart­ place during the 1950’s, the average level man 1957; Homes 1958). With the data of the indices for each and every month for a further four seasons to hand, it being noticeably higher in the second five appears that this increase has now ceased year period (1954-55 to 1958-59) than in (see Figure 5), and that the seasonal indices the first. It is clear, however, that the rate have remained constant at a level which of increase was greater in the autumn than was first attained in the winter of 1957-58. it was in the latter part of the winter. Since It should be stressed, however, that the 1959 the indices for February and March level of these indices depends not only on have shown further gains, and the same is the size of population, but to some extent also true of October and November, des­ on the length of time during which large pite a decrease in the last three seasons. In numbers of birds are present. From the December, on the other hand, the indices

28 THE WILDFOWL TRUST Figure 5. Seasonal indices for Tufted Duck, 1948-1964.

have dropped and for the past five seasons achieved, any further interpretations would the average level has been virtually the be out of place. same as it was 10-15 years ago. These changes in the relative abundance Acknowledgements of Tufted Ducks at various stages of the I am grateful to the Nature Conservancy winter are a subject for further investiga­ for the financial support afforded to the tion. In undertaking it, an attempt must be National Wildfowl Count investigation made to differentiate between the native over many years. I should also like to stocks and the two immigrant populations record my debt to John Frith who so from Iceland and Russia, and to ascertain cheerfully undertook the task of analysing whether or not the trends in the popula­ the data. He died, aged 27, on 28th August tions are the same. Until this can be 1964- References Atkinson-W illes, g. L. (Ed.). 1 9 6 3 . Wildfowl in Great Britain. Monographs of the Nature Con­ servancy No. 3 . London. Eltringham , s. K . and G. L. atkinson-w illes. 1961. Recent population changes in British ducks. Wildfowl Trust 12th Ann. Report: 4 0 -5 6 . EYGENRAAM, J. A. 1964. The wildfowl situation in north-west Europe. Proc. ist European Meeting on Wildfowl Conservation: 2 1 - 2 2 . London. Haartman, L. von. 1957- Population changes in the Tufted Duck, Aythya fuligula (L.). Com­ ment. biol. 16(5): i-ll. h o m e s , R. c. 1958. A ten-year review of duck counts in the London area. London Bird Report 2 2 , for 1957: 36-49.

TRENDS IN BRITISH DUCKS 29 Lead poisoning in îiic Slimbridge wildfowl collection J. V. BEER and P. STANLEY

Sum m ary Rather surprisingly, lead poisoning, following the ingestion of spent shot gun pellets, has been found to be an important cause of death among captive wildfowl at Slimbridge, Gloucestershire. Thirty-two species have been affected and the post-mortem findings are described. The source of the pellets has been investigated. The differential mortality among the various wildfowl tribes is possibly related to differences in feeding habits, diet and gritting as well as to suscepti­ bility. Methods of prevention are discussed. Lead poisoning casualties have also been found in other collections in England.

Introduction from the large BB pellet down to pellets Lead poisoning, caused by the ingestion of the size of No. 6 shot and fragments. Some spent shot gun pellets, has long been still showed signs of denting, others were recognised as an important mortality spherical, while some were eroded to discs factor in free-living wildfowl. Olney (1960) or tiny fragments. The surface of the has given a comprehensive review of the pellets was a dark grey metallic sheen situation. In 1959 and i960 a series of produced by the chemical and grinding deaths occurred in the Magpie Geese action of the gizzard. 47 (63%) of the cases Anseranas semipalmata at Slimbridge, and contained one pellet or fragment of lead some form of poisoning was suspected. while the remainder contained between Then one case showed all the classic signs of two and seven. This amount of lead is lead poisoning and lead pellets were found similar to that found by Jordan and Bell­ in the gizzard. Subsequently a close watch rose (1950) to be sufficient to kill Mallard has been kept for signs of lead poisoning Anas platyrhynchos fed on a diet of mixed in all post-mortems and, in all, 74 primary grain. cases have been detected. These have As in the case of birds poisoned in the occurred in the 32 species listed in the wild, most of the corpses were emaciated. Appendix. This was quantified by grading the pectoral muscles from I (very atrophied) to 4 Post-mortem findings (normal) and the subcutaneous and visceral The pellets found in the gizzard varied fat each, from o (no fat) to 4 (massive

Internal condition of corpse Figure i. Condition of wildfowl poisoned by lead.

30 THE WILDFOWL TRUST deposits). Adding the three grades gives One hundred soil samples each compris­ values ranging from I (extremely emac­ ing 100 ml. of the top six inches were taken iated) to 9 (healthy) to 12 (obese). Figure at random throughout the largest pen i shows that two-thirds of the Slimbridge (6 acres). Not a single lead pellet was cases were emaciated. found, showing that the general level of Many of the birds had nevertheless contamination is not high. Similarly no eaten shortly before death. The accumula­ pellets were found in fifty samples of deep, tion of food in their oesophagi was not soft mud well out in the ponds. Fifty always a direct result of impaction but was samples taken from along the marginal probably caused by a weakening or para­ shelf of the ponds, however, yielded four lysis of the gizzard muscles. Actual pellets. The enclosures are on alluvial soil gizzard impaction was noted in 24 (32%) reclaimed from the river some three cases. The impaction, sometimes extending centuries ago. The edges of newly dug to the proventriculus and duodenum, was ponds are therefore unstable and prone to formed of tough fibrous grass and other crumble into the water as birds dibble and vegetable material which could not be tread along the margins. It is here that any broken down by the weakened gizzard. lead pellets in the soil would most likely Jordan and Bellrose (1951) found proven- to be exposed within reach of the birds. tricular impaction in 44% of their penned Erosion of the pond margins has been a lead-poisoned Mallard. The homy pads major maintenance headache, for the ponds of the gizzard were eroded and ulcerated rapidly increase beyond the desired size, in 9 (12%) of the Slimbridge cases. and fill with mud, while the circulation Anaemia is a common finding in lead channels become choked with silt. To poisoning and was noticeable in 45 (61%) combat these effects it has been the practice of the post-mortems. One Red-billed to line the banks, two or three feet above Whistling Duck Dendrocygna autumnalis and below the water line, with rough cast was markedly anaemic before death, the concrete coloured to simulate earth. This bill and legs being almost white. An is a slow and expensive business so that a enlarged gall-bladder was present in 61 range of ponds with and without ‘anti­ (82%) cases and the excess bile usually erosion’ linings has been available through­ stained the gizzard, and also the cloacal out the enclosures. In ponds with no anti­ and tail , bright green. The liver erosion linings twenty-six samples yielded was atrophied in 15 (20%) cases and some 10 pellets; 21 cases of lead poisoning had deterioration was noted in 24 (32%) cases. occurred in these ponds. In ponds where In addition to the above post-mortem the edges were mostly protected by con­ findings which, coupled with the presence crete twenty-one samples yielded no pellets of lead pellets in the gizzard, are patho­ and there had been only 3 cases of lead gnomic of lead poisoning, congestive heart poisoning. There have been clear instances failure was noted in 20 (27%), kidney where a species, such as the Magpie Goose, impairment in 27 (36%) and pneumonia suffered from lead poisoning when kept in 8 (11%) cases. The parasites Echinuria with access to ponds with natural banks sp. and Amidostomum sp. were only found but not when kept in concrete-edged in 7 and 3 cases respectively, whereas ponds. Hansen, McNeil and Priebe (1957) con­ The pellets found in the gravel on the sidered that infections of the latter parasite marginal shelf were mainly No. 4 and No. 6 contributed substantially to the death of shot. No BB shot was found. All the pellets wild Canada Geese Branta canadensis were pale buff or off-white due to a coating suffering from lead poisoning. of lead hydroxide and salts which had prevented extensive corrosion over the Source of the pellets years. Most of the pellets showed the There has been little or no shooting in the characteristic denting which is produced immediate vicinity of the 35 acres of en­ during firing, but a few were very small and closures at Slimbridge since the Trust was rounded and had possibly already been founded in 1946. Controlled goose shoots ingested and defaecated by a bird. are still held three or four times a year but well away from the pens. In any case the Differential mortality heavy shot used figures relatively It is clear that lead poisoning occurs, under seldom among the pellets found in gizzards. captive conditions at least, much more It seems, therefore, that the pellets now frequently in some groups of wildfowl than finding their way into the captive birds are in others. The known occurrences and the two or more decades old, deriving from total number of post-mortems made in the the time when the area was used for more six-year period 1959-64 are compared in general (but always strictly controlled) Table I, using the taxonomic grouping into shooting. tribes proposed by Delacour (1954-64).

LEAD POISONING 31 Table I. Frequency of occurrence of lead poisoning in post-mortem exami­ nations o f Anatidae kept at Slimbridge, 1959-64

Post-mortems Lead poisoning undertaken cases Tribe number %

Anseranatini 28 6 21 Aythyini 163 22 13 Cairinini 260 17 7 Dendrocygnini 159 7 4 Anatini 530 15 3 47 I 2 Somateriini 44 I 2 Mergini 99 I i Anserini 302 2 < I Tadornini 149 I < I

1781 74 4

It is suggestive that the Anseranatini are which they feed. Moreover, where grit is root eaters with powerful digging bills; short, as in an alluvial soil, not only are that the Aythyini are diving bottom lead pellets more likely to be taken in, but feeders; and that the Cairinini concerned they are retained for longer in the gizzard. (most cases were in the Aix) obtain Excess grit passes rapidly through the their food by picking up individual seeds birds, taking any pellets with it. rather in the manner of poultry. All these It is probable also that both the feeding methods of feeding are likely to bring and gritting habits are different in young them into contact with pellets more birds from those of adults; they may also readily than, say, are the grazing habits of be more susceptible to poisoning. A combi­ most of the Anserini. But for a number of nation of these factors, together with the reasons considerable caution must be necessity for keeping young birds on exercised in relating differences in inci­ temporary, unconcreted ponds, probably dence of poisoning to the feeding habits. accounts for the much greater incidence of Experimental work in America (see Bell­ lead poisoning in birds o f less than one year rose, 1964) has stressed the importance of old. These produced 39 cases (14% ) in 269 the actual diet taken. After a bird has post-mortems; 768 comparable adult post­ ingested a certain number of pellets, lead mortems produced only 23 cases (3%). No poisoning is much more likely to develop case has been found in a downy bird over on a diet of whole grain than if the bird is the six years, but their chances of coming fed grain meal or green stuffs. It is thought into contact with lead pellets in the rearing that the greater abrasion against the cereal pens are small. grains leads to quicker erosion and solution of the lead. In the densely populated Prevention of lead poisoning in collec­ enclosures at Slimbridge natural foods are tion birds rapidly used up and the birds of many The situation at Slimbridge is by no species subsist on an artificial diet rich in means unique as the disease has been cereal grains. In these conditions the found recently in birds from collections in incidence of lead poisoning may reflect Lancashire, Norfolk, Surrey, Hampshire specific susceptibility as well as the likeli­ and Dorset. The general level of incidence hood or otherwise of the birds ingesting (4%) indicated by Table I probably under­ lead. To test the latter thoroughly it would estimates the seriousness of the position at be necessary to make X-ray investigation Slimbridge owing to diagnostic difficulties of the living birds in the collection. The in the earlier years. In 1963 and 1964, by disturbance this would entail is not when the condition was clearly recognised, justified. the general level was 7% (52 cases in 702 Another reason why feeding habits may post-mortems) making it one of the more not be closely linked with the incidence of important single causes of mortality. lead poisoning is that the pellets may be Lead poisoning is difficult to diagnose ingested in mistake for grit rather than for and cure in the living bird, so that methods food seeds. The birds may well obtain of prevention are most important. their grit in places other than those in When a potential collection site is being

32 THE WILDFOWL TRUST considered, the extent of any shooting in removed from a pen or pond should be the past should be ascertained and taken removed entirely or allowed to grass over into account. Ideally the site should be before birds are put back in the pen. A entirely free of lead but, if not, precautions plentiful supply of grit should be made can be taken to keep the incidence of lead available and the diet should contain as poisoning low. The banks of the ponds much green food as possible. should be protected by concrete from erosion, while marginal shelves in shallow Acknowledgements water can be covered with a uniform large We would like to thank Captain R. G. W. gravel. However, if there is an appreciable Berkeley and Mr. W. Bowditch for details amount of water-weed this should not be of the past shooting over the collection area disturbed. New pens and ponds are best and Mr. W. H. Hoff, Mr. T. Jones, Mr. J. populated with feeders and grazing Murray, Mr. D. T. Page and Mr. H. species. The Anseranatini, Aythyini and the Whitehead for details about certain birds. Cairinini should be kept in old pens that Also we would like to thank Mr. S. T. have had the pond banks protected against Johnstone and his staff for collecting the erosion. Any soil or mud that has been dead birds for post-mortem examination.

Appendix. Species that have died of lead poisoning in the Slimbridge w ildfow l collection.

Lead Post-mortems poisoning undertaken cases

Magpie Goose Anseranas semipalmata 28 6 Fulvous Whistling Duck Dendrocygna bicolor 6 1 4 Red-billed Whistling Duck D.autumnalis 33 3 Bewick’s Swan Cygnus columbianus bewickii 2 i Greylag Goose Anser anser 31 i Falkland Island Steamer Duck Tachy eres brachypterus 6 i Salvadori’s Duck Anas waigiuensis 13 I Versicolor Teal A.versicolor 18 I Northern Pintail A.acuta 18 i Chestnut-breasted Teal A.castanea 26 2 Mallard A.platyrhynchos 65 3 Laysan Teal A.laysanensis II i Chinese Spotbill A.poecilorhyncha zonorhyncha 9 i New Zealand Grey Duck A.superciliosa 7 i Philippine Duck A.luzonica 15 i African Yellowbill A.undulata 7 i Cinnamon Teal A.cyanoptera 13 1 New Zealand Shoveler A.rhynchotis variegata 6 I Steller’s Eider Polysticta stelleri 26 I Rosy-bill Netta peposaca 4 I South American Pochard N.erythrophthalma 12 2 European Pochard Aythya ferina 7 I Redhead A.americana 25 9 Common-White-eye A.nyroca 3 2 Australian White-eye A.australis 13 i Tufted Duck A.fuligula 6 I Lesser Scaup A.affinis 12 i European Greater Scaup A.marila 1 4 3 Brazilian Teal Amazonetta brasiliensis 2 7 3 Mandarin Duck Aix galericulata 30 2 North American Wood Duck A.sponsa 10 6 13 + 1 pull. European Goldeneye Bucephaia clangula II I North American Ruddy Duck Oxyura jamaicensis 7 I

LEAD POISONING References BELLROSE, F. c. 1964. Spent shot and lead poisoning in Waterfowl Tomorrow, edited by J. P. Linduska. 770 pp. U.S. Dept. Interior, Washington. DELACOUR, J. 1954-64. The Waterfowl of the World. 4 vols. Country Life, London. HANSEN, H. A ., c. w. m cneil and M. D. PRIEBE. 1957. Mortality of Canada Geese with impacted gizzards in E. Washington, 1949-1954. J. Wildl. Mgt. 21: 96-98. JORDAN, J. s . and F. c . BELLROSE. 1950. Shot alloys and lead poisoning in waterfowl. Trans. N. American Wildl. Conf. 15: 155-170 j o r d a n , J. s. and f. c. Bellrose. 1951. Lead poisoning in wild waterfowl. 111. Nat. Hist. Surv. Div. Biol. Notes 2 6 : 2 7 pp. C LN EY , p. J. s. i960. Lead poisoning in waterfowl. Bull. Brit. Orn. Club 80(3): 35-40; (4): 53- 59-

Breeding success of White-fronted Geese from the Nenets National Area

H U G H B O Y D

Sum m ary The breeding success of White-fronted Geese has been inferred from the age composition of flocks wintering at Slimbridge, Gloucestershire, since 1947. These Whitefronts breed in the north east of European Russia. Annual variations in brood-size (average 3 -24) have been com­ paratively slight, though there were unusual numbers of small broods in 1950 and 1958 and of large broods in 1951 and 1956. The proportion of first-winter geese has varied widely about a mean of 33-3%. The fluctuations seem to have reflected changes in output rather than in adult mortality. Attempts to relate production to the limited weather data from the breeding areas by means of correlation methods suggest that wet weather in July has markedly reduced production. Snow in late May and early June has been less important, while low temperatures without snow have had no perceptible effect. Alarked geese breeding for the first time, at nearly three years old, have had smaller families than parents four to six years old. So have those more than seven years old.

Introduction tion of young geese is compared with The best way of studying the fertility of annual variations in the losses of full-grown geese and the factors affecting it is by birds. The results of all three lines of direct observations on breeding groups inquiry are tentative. Their thorough continued over many years. For species exploration would require a great increase nesting in the Arctic such investigations in efforts to catch and mark geese, as well are very rarely practicable but much of the as access to detailed weather records not pertinent statistical information can be available outside the U.S.S.R. obtained by studying flocks in winter Recoveries of ringed birds have shown (Lynch and Singleton, 1964). The White that nearly all the Whitefronts visiting fronted Geese Anser albifrons albifrons that Slimbridge breed at the western end of the visit Slimbridge, Gloucestershire, have range o f A.a.albifrons, on the south island been studied in this way since 1947 (Lebret of Novaya Zemlya and on Vaygach and 1948, Boyd 1954,1957). The present paper Kolguev Islands and on the tundra of the adds data collected since 1956 and examines Nenets mainland from the Kanin peninsula three factors likely to affect the output of east to about 55°E (Shevareva 1959, Boyd young. First, attempts are made to use 1961). The Slimbridge-visiting White­ published weather records to investigate fronts do not form a simple closed group. the effects of weather conditions on the They are part of a much larger stock breeding grounds upon reproductive suc­ wintering chiefly in east Germany and the cess. Second, records of the family-sizes of Netherlands with a breeding range extend­ marked geese are used to illustrate varia­ ing as far as 70°E. (Philippona and Mulder, tion in output with age. Third, the propor­ i960). The consistent reappearance of

34 THE WILDFOWL TRUST ringed geese suggests that a high propor­ subsamples within any year are not inde­ tion of the geese that have once visited pendent. Because of differences in the Slimbridge continue to do so, but the accessibility of the geese and in the amount extent of the gains and losses due to of time spent in searching, the annual infidelity to tradition, rather than to births samples summarised in Table I do not and deaths, has yet to be measured. For the reflect the changes in the numbers of geese purpose of the ensuing analyses it is arriving at Slimbridge in autumn (compare assumed that the reproductive perform­ columns (1) and (4) with column (6) ). ance of immigrants is much the same as The means and the frequency distribu­ that of persistent members of the group, tions of brood-size show considerable although recent work in the Netherlands superficial differences between years. The has shown marked differences between standard errors of the means are relatively flocks wintering in different parts of that large, often because the samples have been country (W. J. Doude van Troostwijk, small but also because the distributions are personal communication). platykurtic and positively skewed. The coefficient of variation is always very high Fertility (from 36-2 to 53-8 even in the largest Two measures of annual production can be samples). Thus significant departures from got by looking at Whitefront flocks in the average are only demonstrable in four autumn: the proportion of birds in first- of the seventeen years. In 1950 and 1958 winter plumage and the sizes of family there were few large broods: in 1958 there parties. Both measures tend to diminish were very few broods at all and an un­ through the winter, because young geese usually high proportion of ones and twos, are more vulnerable than older ones (Boyd while in 1950 there was a marked excess of 1957)5 so that records collected in the twos and threes. In 1951 and 1956 there autumn best reflect the success of the were exceptionally many broods of more previous breeding season. Whitefronts than four young. have been scarce at Slimbridge before Column (5) of Table I records the pro­ December, particularly in recent years, portion of first-winter birds observed each and the earliest arrivals tend to be unrepre­ autumn. Marked departures from the sentative, so that for adequate samples it is average value for the total sample appear necessary to lump together data from to have occurred in thirteen of the seven­ October, November and December. Since teen years, only the values for 1949, 1954, most early arrivals remain for long periods, 1956 and 1959 lying close to the mean. This and so may be looked at repeatedly, the great variability is paralleled in the sub­

Table I. Annual measures of breeding success of White-fronted Geese seen at Slimbridge in October-December, 1947-63. Values in italics show departures from the long-term means significant at the 5% level. proportion mean ist winter birds no. of brood s.e. of sample ist w. max. number broods size means size per 1000 seen before 31 Dec. « (2) (J?) Í4) (5) (6) 1947 II 3'55 0-47 606 206 3000 1948 49 3 '22 0-21 184 196 1500 1949 45 3 29 018 466 290 650 1950 252 3 04 0-08 3511 391 3000 1951 176 366 0-14 3166 402 1900 1952 282 322 009 3647 372 3900 1953 105 3 19 0 16 I9OO 242 1500 1954 4 4'75 0-55 9OO 311 1000 1955 114 3 24 o-i6 9OO 470 1270 1956 102 367 0-19 683 326 1700 1957 133 3 54 0-15 I5OO 462 2200 1958 48 2-54 015 8O7 124 700 1959 239 3 05 010 2893 346 1400' i960 106 3 30 016 994 371 780* 1961 22 386 036 381 454 450 1962 43 279 0-20 2039 IO8 145a 1963 37 2 84 0-23 615 228 1000 total 1756 3 24 OO38 25192 mean 333 mean 1610

BREEDING SUCCESS OF WHITEFRONTS samples within a year and is undoubtedly pleasant. Snow cover persists on Kolguev affected by incomplete mixing of young for over 230 days a year and on Vaygach and old birds within flocks due to the for 250 days, while the rivers of the Kanin persistence of family parties. Boyd (1956) peninsula are frozen over for more than has discussed a similar situation in Anser seven months (Zaborski, 1955). In the brachyrhynchus from a statistical point of summer “ Kolguev is exceedingly subject view. to fogs and gales of great duration” Although by ingenuous statistical cri­ (Trevor-Battye, 1895) and Novaya Zemlya teria the mean brood-sizes show few is even worse. Though there is a long- ‘significant’ differences while the propor­ established chain of weather stations in the tions of young birds show many, the area, full records are not published outside correlation between the annual values for the U.S.S.R. and the only data immediately the two measures is much greater than available are those provided by The Daily m ight be expected (r = + 0-62). Taken Weather Report of the British Meteoro­ in conjunction with the fact that even in logical Office. T h e synoptic map for 1200 h. 1958 and 1962 the proportion of young GM T published in the Report includes geese did not fall below 10% this leads to a data from three mainland stations in or general inference of major importance: the near the breeding range of Slimbridge- variations in production of young seem visiting Whitefronts (at Cape Kanin, more likely to be due to differences in Tabseda and Amderma), from Vaygach rearing success than to alterations in the Island and from Malye Karmakuly on the number of geese laying eggs. Clearly, west coast of the south island of Novaya taking the entire range of this Nenets stock Zemlya. There is no report from Kolguev. as a whole, no year since 1947 has been a The data comprise wind direction and “ non-breeding” year in the sense of a year speed, present weather, temperature and in which breeding was wholly prevented or cloud cover. Such a set of instantaneous abandoned (Marshall, 1952). Variations in observations is far from ideal for assessing brood-size in autumn might reflect either the impact of the weather upon nesting differences in the numbers of eggs laid or geese, especially as until very recently in hatching or fledging success. Only direct there were many gaps in the plotted observations in nesting areas could distin­ records. For 1947-50 it has been possible guish between these alternatives with to supplement the D.W.R. records with certainty but it is possible to make some the monthly mean temperature and total progress by studying the phenology of precipitation at Malye Karmakuly and nesting and the effects of weather. Voygach published in World Weather Records 1941-50 (Weather Bureau, U.S. Breeding phenology and weather data Dept, of Commerce, Washington, 1959). Irregular observations scattered over many There is an encouraging measure of agree­ years, summarised by Dementiev and ment between the published monthly mean Gladkov (1952) and Shevareva (1959) led temperatures and those calculated from to the general phenological picture given the D.W .R. data. More surprisingly, there in Table II. In addition to the evident is a satisfactory consistency of trend differences between one place and another, between the records of total precipitation there are important differences from year and an index of “days-with-precipitation to year, though the data are too fragmen­ recorded at 1200 h. G M T ” derived from tary to show this well. Both types of the D .W .R . variation are due to climatic differences. From studies of other geese nesting in The weather around the shores of the various parts of the Arctic (see especially Barents Sea is usually extremely un­ Barry 1962, Cooch 1961, Goodhart and

Table II. Phenology of White-fronted Geese in the Nenets National Okrug, around the south-east shores of the Barents Sea.

Kanin Kolgnev Novaya peninsula Island Zetnlya first arrivals May 9-23 May 25-June 5 May 15-25 laying begins May 29-June 8 June 4-20 incubation begins June 5-15 June 11-28 hatciiing begins July 1-12 July 7-25 July 13-28 first voung fledged August 4-26 Zug. 10-Sep. 10 final departures after Sep. 19 from Aug. 31 Sep. 4-Oct. 7 length of stay 105-140 days

36 THE WILDFOWL TRUST Tafele III. Yearly variations in temperature and rainfall in Whitefront breeding areas, Alay-july.

May 16-June 15 July mean temperature & rainfall index weighted rainfall index mainland N. Zemlya means mainland N. Zemlya mean °C rain °C rain °C ram

1947 -0 7 0 ? —0-6 0 ? — 0-6 0 ? 31 250 140 1948 -2-6 80 — i l 95 + 0-5 88 56 0 28 1949 - 3'3 6l + 0-5 62 + 1-8 62 48 133 93 1950 69 I39 - 0-9 148 + 2-6 144 132 107 120 I95I ~4'3 0 - 1*3 130 + 1-2 65 0 160 80 1952 - 4 'i 67 + 1-6 m + 2-7 89 26 71 49 1953 -7-1 20 + 1-0 36 + 3 7 29 78 69 74 1954 -6-2 92 + 2*4 6 5 + 4 'i 79 20 32 26 1955 - 5 -Q 89 -0 .3 43 + 2-4 66 41 0 20 1956 H-47 87 +0-4 148 + 2-3 118 0 0 0 1957 - 3-4 240 — 0.2 276 + 1-4 258 43 129 86 195S -0-6 182 + 2-7 321 -I -7 252 104 345 225 1959 -2-5 244 — 0-2 281 + 1-0 263 0 348 174 i960 -1-8 3 0 5 -f o-i m + 0-9 208 83 200 142 1961 - 0-4 ISS — I I 250 - 0-5 194 14 77 46 1962 -3 7 2O7 — 10 200 + I - I 204 133 172 203 1963 -2-2 235 —o-i 100 + 0-9 168 127 103 115

Wright 1958, Maclnnes 1962) it seems two means are positively correlated, likely that weather conditions are especially especially on the Nenets mainland. Crad­ liable to affect breeding success at two dock and Ward (1962) have demonstrated periods in the nesting cycle. First, cold an association between temperature ano­ weather at the time of arrival of the geese malies in May and June in this region. in the spring may make it difficult or In testing hypotheses about association impossible for them to lay eggs, by delay­ between weather characteristics and breed­ ing the disappearance of snow cover from ing success it is proper to use non-para- nest sites or by fresh falls of snow. Second, metric techniques, since the available cold, and especially wet-and-cold, weather weather measurements are unlikely to be around the time when most clutches are metrical with respect to the factors that hatching or goslings are less than two directly influence egg-laying or the survival weeks old may also lead to relatively high of goslings. On the assumption that the losses. Table II shows that in the Nenets relationship between the variables is linear, region the first of these critical periods falls rank correlation coefficients have been somewhere between 16th May and 15th calculated to test association between the June, while the second may occur during scales of breeding success provided by most of July. Table III summarises the mean brood-size, proportion of first-winter relevant weather data for each year from birds and their joint rank order and the 1947 to 1963. Means for late May and for indices of May-June temperature and early June were also calculated separately. precipitation, July precipitation and their Their use affords no additional insight. The combined rank orders (.Table IV). From

Tafele IV. Rank correlation coefficients between measures of breeding success and of weather in the breeding season

measures of breeding success mean proportion combined brood-size of young ranking weather 16 May-15 June temperature + 0-27 + 0-41 + 0-10 precipitation - 0 -45* — o-oi —0-05 combined ranking +0-25 +0-09 -rO*23 July rainfall index — o-6i** - 0 -57* — 0-62** good summer weather -f-o-43* * significant at 5% level; ** significant at 1% level

BREEDING SUCCESS OF WHITEFRONTS 37 these coefficients, successful breeding available. There seems to be a marked appears to be positively correlated with difference between the relation of Nenets generally fair spring and summer weather. Whitefronts to the spring weather and that The only correlation between measures of of the Barnacle Geese Branta leucopsis and success and the weather in late May and Brent Geese B.b.bernicla which nest in the early June that is significant at the 5% level same region. For those species, both in suggests that broods were larger after dry Siberia and elsewhere, a delay in the start springs. of nesting leads to the abandonment of Since the assumption of linearity in the laying for that year. Perhaps the apparent relationships between weather and breed­ relative invulnerability of the Whitefront ing success may be unreasonable, contin­ population is due to ability to remain on gency tables have also been used to its breeding grounds well into September, compare the observed frequencies of good, which the other species seem not to do. average and bad output with various However, too little is known about the groupings of weather conditions. No con­ timing of departures for this point to be vincing association between spring tem­ explored thoroughly at present. peratures and breeding success could be All three indices of breeding success are demonstrated in this way either. strongly correlated with the rainfall in July, Analogy with the reported behaviour of production being high in years of low other geese nesting in other parts of the rainfall and poor in wet years. Perhaps this Arctic led to the expectation that the correlation is well marked because the condition of the environment at the times annual differences in rainfall in July tend of arrival of the geese would be of primary to be great. importance. In particular the extent and persistence of snow cover has been shown Effects of age upon fertility to determine how soon Branta bernicla and Continued observations upon the small A . caerulescens may begin to nest (Barry, number of ringed geese in the flocks at 1962, Cooch, 1961). The weather at the Slimbridge have confirmed the earlier time of return is important in such cases evidence that one- and two-year-old geese because of its effect on the snow cover, are not accompanied by offspring and that rather than on the geese themselves, which a smaller proportion of three-year-olds arrive ready to lay eggs. Dementiev and have families than do geese four years or Gladkov (1952) state not only that a delay more old (Boyd, 1954,1957). More remark­ of 10-16 days occurs between the arrival of ably, it now appears possible that produc­ Whitefronts and the beginning of laying tion of young may fall off with increasing but also that the geese arrive with the age after no more than four years of gonads in a relatively undeveloped state. maturity. The evidence is meagre, because If there is indeed little urgency about the very few geese of precisely-known age can beginning of nesting in this Whitefront be found, so that the performance of older population the weakness of correlations birds can only be inferred by comparing between early spring weather and breeding the output in successive years after mark­ success becomes less surprising, especially ing of all ringed geese seen, including those since no measure of the extent of snow whose age at marking was not known. cover in the middle of May has been Perhaps Table V shows no more than a

Table V. Variations in production of young with increasing age, from observa­ tions of families accompanying ringed White-fronted Geese at Slimbridge (a) Proportion with broods years after marking i 2 3 ' 4 5 6 + total with broods 36 39 36 24 7 4 14 6 without broods 25 18 12 7 10 4 76 61 57 48 31 17 8 222 proportion with broods 0-59 0-68 0-75 077 041 0-50 10 55, 010 > P > 0 05

(b) Size of broods broods of proportion of broods 1,2 3,4 5 4 total small large years 1,2 38 28 9 75 0-50 0-12 later 3,4 28 16 16 60 0-47 0-27 5 + 3 7 I II 0-27 009 total 69 51 26 146 X1 = 9 60, 0 05 > P > 0 02

38 THE WILDFOWL TRUST tendency to stability of breeding perform­ struct a table of the number of recoveries ance with increasing age. The point needs expected in each year. The losses in any further exploration, though this cannot be one year can then be estimated by multi­ done without a great increase in the number plying the average rate (27%) by the ratio of geese ringed and successfully detected (recoveries reported)/(recoveries expected). many years later. It seems unlikely that a The results are summarised in Table VI. reduction in the number of young reared after the age of eight or nine years could be Table VI. Estimates of annual losses related to senescence, for captive White- of White-fronted Geese (from one ist fronted Geese have often lived for fifteen October to the next) obtained from years or more and wild-caught birds have recoveries of ringed birds, 1950-64 sometimes not begun to breed in captivity until over ten years old. recoveries annual The suggestion in Table V that a high year reported expected losses (%) proportion of young parents rear only one or two goslings is consistent with observa­ 1950-51 2 5 39 10-0 tions on geese of several species nesting in 1951-52 8 7-04 30-7 captivity, in which there is a general 1952-53 i i 10-50 28-3 tendency for geese nesting for the first time 1953-54 19 1359 37'7 to do less well than more experienced 1954-55 6 9 93 16-3 1955-56 10 7-24 individuals. This inefficiency of first 37-3 1956-57 6 5 29 30-6 breeders may account for the existence of a 1957-58 I 3 -8i 7-1 negative serial correlation (rs = — 0-516) 1958-59 16 15-15 28-5 between the proportions of young birds 1959-60 14 20-26 187 observed in year N and in year N + 3, a 1960-61 12 14-59 22-2 year of large output being followed three 1961-62 15 10-52 38-5 years later by an increase in the breeding 1962-63 19 12-07 42-5 stock but a reduction in breeding success. 1963-64 5 8-56 15-8 In contrast, no statistically significant total 144 27-0 correlation is apparent between the pro­ 143-93 portion of young birds seen in year N and those found one, two, four or five years The hypothesis to be tested is that a later. relationship exists between the proportion of young geese found in the autumn and Annual mortality and production the losses of adults in the preceding year. It has so far been assumed that variations The correlation coefficient between the in the observed proportion of young geese proportion of young geese in the autumn in the autumn are chiefly due to differences of year N and the adult losses in the in the number of young reared. This preceding twelve months is — o-2i, a assumption needs justification because it is value far too low to provide good evidence theoretically possible that the changes for such a relationship (0-5 > P > 0-4). T he could be brought about in another way, if use of multiple regression coefficients, the number of young reared were relatively partialling out the effects of brood-size and constant but the survival of adults altered of summer weather upon the proportion appreciably from year to year. A detailed of young geese in autumn, serves to reduce study of adult losses is in preparation. For the value of the coefficient. Thus, on the the immediate purpose attention will be available data, it appears that annual varia­ confined to a set of estimates of annual tions in adult mortality do not lead to losses in the years 1950-51 to 1963-64. important differences in the autumn age These are derived from recoveries of geese ratio. ringed at Slimbridge in February or early March in eight years between 1948 and Discussion 1962. Applying the maximum-likelihood The publication of results as tentative as modification of Lack’s method devised by these can best be justified by considering Haldane (1955) to the entire recovery the feasibility of alternative, more rigorous, series, the average annual mortality rate is methods of studying the factors affecting found to be 27-0 + 3-6%, assuming that gosling production. In the case of the the rate does not vary with the ages of the Nenets Whitefronts political difficulties birds. (This assumption appears to be well preclude direct observations by foreigners. justified, especially since no Whitefront Even in politically-accessible areas it will has been ringed before it was at least always be comparatively expensive to put months old.) Using this constant value of observers into breeding areas in the spring 27% and the number of recoveries from before the return of the geese and to main­ each year of ringing it is possible to con­ tain a watch throughout the breeding cycle.

BREEDING SUCCESS OF WHITEFRONTS 39 It can be done, as the outstanding efforts of possibly relevant factors over many years the Canadian Wildlife Service have shown deserve investigation. In the writer’s (Barry, 1962, Cooch, 1961, Lemieux, 1959). opinion the work reported here suggests The present study should also have shown that in carefully-selected cases the combi- the desirability of looking at the behaviour nation of observations in winter and of of geese nesting in the low-arctic to see weather data from established meteoro- how it differs from that of the high-arctic logical stations may be of value. Some species studied in Canada. But, supposing Arctic weather stations keep records of the that observations in breeding areas must extent of snow cover. It would be instruc- always be few and short-lived, any methods tive to repeat analyses of the type attempted of maintaining continuous records of here for a population nesting around a fertility and of analysing the effects of station providing such full weather data.

References BARRY, T. W. 1962. Effects of late seasons on Atlantic Brant reproduction. J. Wildlife Mgr... 2 6 : 1 9 - 2 6 . BO YD, H . 1954. White-fronted Goose statistics, 1952-53. Wildfowl Trust 6th Ann. Report: 73-79. b o y d , H . 1956. Statistics of the British population of the pink-footed goose. J. Anim. EcoL 25: 253- 273- b o y d , H. 1957. Mortality and fertility of the White-fronted Goose. Bird Study 4: 80-93 . b o y d , H. 1961. The migrations of British geese and ducks. Pp. 75-84 in: The New Wildfowler, ed. N. M. Sedgwick, P. Whitaker and J. Harrison. London. COOCH, G. 1961. Ecological aspects of the Blue-Snow Goose complex. Auk 78: 72-89. c r a d d o c k , J. M . and r . w a r d . 1962. Some statistical relationships between the temperature anomalies in neighbouring months in Europe and western Siberia. Met. Office Sci. Paper No. 12: 1-31. De m e n t i e v , G. P . and N . A. Gl a d k o v (eds.). 1 9 5 2 . The Birds of the Soviet Union, vol. 4: 301-306. (In Russian.) GOODHART, J. and T. W r i g h t . 19 5 8 . North-east Greenland Expedition 1 9 5 6 . Wildfowl Trust 9th Ann. Report: 1 8 0 - 1 9 2 . Ha l d a n e , J. B. s . 19 5 5 - The calculation of mortality rates from ringing data. Acta X I Congr. Int. Orn. : 454-458. l e b r e t , t . 1948. Waarnemingen over luftijdsgroepen bij Kolganzen, Anser albifrons (Scop.). Ardea 36: 198-200. l y n c h , J. J. and J. R. s i n g l e t o n . 1964. Winter appraisals of annual productivity i n geese and other water birds. Wildfowl Trust 15th Ann. Report-. 114-126. m a c i n n e s , c . d . 1962. Nesting of small Canada Geese near Eskimo Point, Northwest Territories. J. Wildlife Mgt. 26: 247-256. m a r s h a l l , A. J. 1 9 5 2 . Non-breeding among Arctic birds. Ibis 94: 310-333. p h i l i p p o n a , J. and t h . m u l d e r . i9 6 0 . Het Voorkomen van de Europese Kolgans, Anser a. albifrons (Scop.), in het bijzonder in Nederland. Limosa 33: 90-127. s h e v a r e v a , t . p . 1959. Some facts concerning the migration of wildfowl nesting in the north of the U.S.S.R. Migratsii Zhivotuykh 1 : 95-123. (In Russian.) t r e v o r -b a t t y e , a . 1895. Ice-bound on Kolguev. 458 pp. London. z a b o r s k i, b . 1955. U.S.S.R.: Arctic Archipelagoes. Pp. 486-498, in: Geography of the Northlands, ed. G. H. T . Kimber and D. Good. New York.

Brent Geese in western Europe during the winters of 1962-63 and 1963-64 P. J. K . B U R T O N Summary Hard weather during January and February 1963 concentrated most of the population of Dark- bellied Brent Geese into England and France, making a good estimate of numbers possible. The population in mid-January 1963 was between 23,000 and 25,000. Less comprehensive counts during the winter of 1963-64 suggest that the numbers were then much the same. Very few young were recorded from any areas during 1962-63, but during 1963-64 counts from all areas lay within the range 30-40% first-winter. The Pale-Bellied Brent wintering in Ireland have had two successful breeding seasons in succession, with about 39% young in sample counts in 1962-63, and about 33% in 1963-64. Introduction Although the winter of 1962-63 was excep- counts made of Brent Geese were more îionally severe throughout Europe, the comprehensive than any obtained pre-

40 THE WILDFOWL TRUST viously. In part, the weather helped by inland during January and February. The concentrating Brent into relatively few snow cover was very thin for most of this areas. Such full coverage was not attempted time, and did not hinder grazing very during 1963-64. During 1962-63, a special much. Inland foraging was also reported appeal was made for observations regard­ from Foulness, Canewdon, Fambridge ing the effect of the hard weather on Brent and Leigh-on-Sea (P. Stockwell, Miss M. Geese and these, together with details of Drake). Many instances of extremely tame counts in both winters, are given below. behaviour occurred; one party of 38 landed Counts of age-ratios and total populations on the children’s paddling pool at Leigh- were made in all major wintering areas in on-Sea, while others on the shore in the both winters. same area allowed dogs to approach within a few yards before taking flight. A single Dark-bellied Brent Goose Branta b. stray found its way to Hanningfield bernicla Reservoir. Despite all this, only 10 dead ENGLAND Brent were reported in Essex, contrast­ Devon ing with high mortality of several other 24 on the Taw estuary, 17th February, coastal species, particularly Shelduck. 1963 (A. J. Vickery). The maximum during 1963-64 was 8,813 on 15th December, 1963. In counts made Hampshire and Sussex by the writer, 464 first winter birds were Details for Langstone and Chichester found in a total of 1,420, about 33%. Harbours in both winters have been received from B. W. Renyard. The maxi­ Herts mum combined total for both harbours 2 at T ring Reservoir, 16th M arch, 1963 during 1962-63 was 1,500 on 12th January. (N. E. Gammon). No first-winter birds were seen. The main feeding areas of the Brent were not as Norfolk badly affected by ice as the upper part of At Scolt Head, 500 were present from late the shore, and thawed more quickly. The December 1962 to the beginning of March flocks split up more than usual, and one 1963, but no young at all were found sickly bird was seen. Otherwise, the (R. Chestney). There were 2,500 altogether weather appeared to have little effect on at Blakeney and Wells on 25th January, Brent in these areas. 15 were recorded at 1963 (H. Hunt). About 10% first-winter Christchurch Harbour on 4th January, birds were estimated at Blakeney (R. A. 1963 (A. J. Wise). Richardson). During the following winter, an un­ In the autumn of 1963 the first arrivals usually large influx occurred during mid- at Scolt Head were 57 on 25th October, December, and the flocks quickly became earlier than usual. 350 were counted there scattered, making counting difficult. The on 6th January, 1964, and from then until highest full count for the two harbours was 26th February numbers fluctuated between 1,360 on 14th December, 1963. Counts of 350 and 550, the proportion o f your;g numbers of young birds in the flocks remaining constant at 28%. The majority during the winter totalled 377 out of 919, left by early April and the last seen were 4 1 % . three on 3rd May, 1964 (R. Chestney). Kent Wash In the north, about 370 were present at (Lincs. and Norfolk). D. Broom estimated Shellness and Egypt Bay on 1 ith Novem­ the average number present during Janu­ ber, 1962. During mid-January 1963, the ary 1963 at about 3,500. total is not thought to have exceeded 150, most of these birds being on the Medway Northumberland. and Swale (D. F. Musson). At Pett Level, Some 2,000 appeared at Holy Island about a flock of from 60 to 80 (including one New Year 1963 and stayed until the end Pale-bellied bird) flighted regularly up to a of the cold weather. There were no signs mile inland during February 1963 (H. F. of increased mortality (F. Stabler). These Greenfield, Dr. J. G. Harrison). birds are assumed to represent most of the Spitsbergen section of the Pale-bellied Essex population. The maximum count during 1962-63 was 128 Brent arrived on ist December, 1963, 9,495 on 13th January, 1963 (R. V . A. and increased to 3-400 by 13th. These are Marshall). No first-winter birds were seen thought likely to have been Dark-bellied at all throughout the winter. In the Brad- birds. By mid-February 1964 5-600 geese well area, Brent fed regularly on the salt­ were present, most likely Pale-bellied ings and to a lesser extent on pasture fields (F. Stabler).

BRENT GEESE IN EUROPE 41 Cheshire Manche 80 2 seen flying east at Leasowe Shore, Côtes du Nord 130 Wirral, on 6th January, 1963 (B. W. Finistère 110 Kendrick) were most likely to have been Morbihan 5,230 Dark-bellied. Vendée 150 Charente-Maritime 400 Gironde 300 WALES Glamorgan Total 6,400 25-35 were present on the Burry Estuary, The counts from Manche, Côtes du Gower, during January 1963. In January Nord, Vendée and probably Gironde may 1964, a maximum of 37 were recorded at be underestimates. Counts of first-winter Whiteford Point, and on 2nd February, 12 birds were made as follows :- first-winter birds were seen in a flock of 32 (D. Cabot and R. Howells). Morbihan : no young seen out of approx­ imately 1,250 examined (R. Bozec). 7 Anglesey young out of 149 (F. Roux). 2 first-winter birds at Newborough Warren Côtes du Nord: 4 young out of 11 on 27th January, 1963, are virtually certain (J. P. l ’Hardy). to have been Pale-bellied (P. Hope Jones). Vendée: none seen in 760 (Dr. Ricou- leau). CHANNEL ISLANDS In Morbihan, the Zostera was frozen, Jersey and the Brent left the reserve where they The maximum total in 1962-63 for St. usually enjoy protection. A massacre was Aubyn’s and Grouville Bays was 410, on averted by the suspension of shooting on a 21 st January and again on 22nd February. national scale throughout the severe On 13th January, 1963, when counts were weather. On 19th and 20th January, small made in several countries to coincide with parties and individuals were reported the British wildfowl count, there were 350. ¡feeding on fields near the sea in company with Whitefronts in Manche, Seine Mari­ Guernsey time and Pas de Calais. Records north of 27 on 20th January, 1963, three on 21st and the Seine are unusual, as is the record of 22nd (W. A. Burridge). None was seen 76 at the entrance to the port of Croix de during 1963-64. Vie, Vendée, on 22nd January. Despite this disruption of their normal routine, the Herrn mortality of Brent in France is not con­ This was not visited during 1962-63, but sidered to have been any higher than in a 90 were seen on 21st December, 1963, normal winter. 75-80 on 30th March, 1964, and 40 on Counts in January and February 1964 13th April (W. A. Burridge). recorded between 9,560 and 10,680 in­ dividuals in 19 localities. Several suitable DENMARK areas in Charente-Maritime, Côtes du Nord and Finistère could not be searched (Details submitted by Mette and Jorgen and it is likely that the true number of Fog.) No young were seen at Jordsand in Brent wintering in France lay between the autumn of 1962, where the maximum 11,000 and 12,000. (F. Roux and F. Spitz: count was 1,300 on 15th October. Most Les recersements d’anatides en France Brent left Denmark when the severe pendant l’hiver 1963-1964. Oiseaux de weather started, and a series of aerial France 14(4): 1-17. 1965.) Counts of age counts during January 1963 only revealed groups in Morbihan by Abbé R. Bozec 720 on the 13th in East Jutland. gave a total of 134 young out of 449, about In 1963-64, details were submitted of 3° % - 167 shot birds in the autumn; n o of these were young. On 12th January, 1964, an HOLLAND aerial count in Jutland revealed 230 birds. The number of Brent in Holland during the severe weather of 1962-63 appears to have been negligibly small. Few were seen FRANCE in the Kattendijke area until 19th March, During 1962-63 a series of counts was 1963, when there were 136. Numbers seen organised between 9th-i5th January by on Terschelling during autumn 1962 were F. Roux. The counts covered all but a few considerably smaller than in previous of the regular wintering areas of Brent on years, and the proportion of young the French coast. The results were:- recorded was about 5%.

42 THE WILDFOWL TRUST In 1964 about 300 were counted at fared much better than most wildfowl Veerse Meer on 10th January, and 160-180 during the hard weather. For the most on 2nd February. On the latter date, 12 part, an alteration of normal feeding young were seen in a flock of 40. A t behaviour was the principal effect, and Terschelling a maximum of 1,400 was even the number of strays reported from attained on ist December, 1963, with the unusual areas was no more than in most percentage of first-winter birds decreasing winters. from 33% in October to 8% in January, The results of age-group counts since 1964. 1954-55 are summarised in the table below. (Details for South Holland were sent Figures from 1954-55 to ! 957-58 refer to by T. Lebret, and for Terschelling by Essex only while those from 1958-59 on­ J. Tanis.) wards are based on results from several areas. SPAIN Although it might have been expected that Proportion of young birds larger numbers of Brent than usual would Season in Dark-bellied in Irish Pale-bellied visit Spain as a result of the severe weather, population population there is no evidence that this occurred. 1954-55 40% ? Some were seen near Baldayo, province of 1955-56 26% ? Coruña, where a few occur in most winters 1956-57 7% ? (Don Mauricio Gonzalez Diez). 1957-58 53% ? 1958-59 hardly any ? Discussion 1959-60 20% ? An attempt was made to synchronise ail 1960-61 50% 39% counts in all areas with the British National 1961-62 7% none 1962-63 Wildfowl Count on 13th January, 1963. 5% 39% 1963-64 35% This was almost completely successful, and 33% the population during mid-January may be put with some confidence at between Pale-bellied Brent Goose Branta b. 23,000 and 25,000. This total is consider­ hrota in Ireland ably greater than was expected, considering Details of Brent observations in Ireland that two poor breeding years had passed have been collated by Major R. F. Rutt- since the population was estimated in ledge. 1960-61 at ‘between 21,000 and 26,000’ By contrast with Dark-bellied Brent, the (13th Annual Report). It is virtually certain Irish Pale-bellied birds evidently had a that the earlier estimate was too low. The good summer in 1962. Counts of the discrepancy underlines the fact that the proportion of young in the flocks at several coverage of Continental wintering areas is different wintering areas made by D. still incomplete, notably in Germany. The Cabot, T. R. E. Devlin, F. King and greater success of counts during 1962-63 Major R. F. Ruttledge, gave a total of 256 must largely be due to the hard weather first-winter birds out of 659, or approxi­ driving Brent out of areas where they mately 39%. Counts of total numbers were normally escape observation, into regions drastically disrupted by weather condi­ well covered by counters. Nevertheless, tions, but it appeared that numbers were mortality between February 1961 and in fact rather higher than in the previous January 1963 was low, probably reflecting year, especially in Counties Kerry and the lower mortality of the adults which Wexford. formed the bulk of the population over this During 1963-64, counts in the same period. areas by A. C. Baird, D. Cabot and Major The counts made in various areas during Ruttledge totalled 1,138, of which 371 1963-64, though less comprehensive, give (33%) were birds of the year. a general picture of numbers maintained, but not increased. Since the proportion of Ackn o wledgements young was about 35% during this winter, All the observers above, and many others, higher total figures might have been ex­ have helped to make this report on Brent pected. The hard weather of the preceding population the most comprehensive winter may have been partly responsible achieved. Their labours during two win­ for the failure to increase. However, reports ters, one of Arctic severity, deserve the from all areas make it obvious that Brent warmest thanks and congratulations.

BRENT GEESE IN EUROPE 43 Birds at Borough Fen Decoy, 1964

W . A . C O O K

This is an account of observations on birds and ears were cocked for the first warbler at Borough Fen Decoy from January to which did not oblige until 12th April, when December 1964. More of the available time three Chiff-chaffs were seen and heard in was spent on counts and nest records than the wood. These were followed by Willow on ringing, so that it is rather surprising Warblers on 13 th, Blackcap the next day that the total of 1,480 birds marked (Table and Whitethroat on 21st. A new species I) is the highest since ringing started in for the Decoy, a Grasshopper Warbler, i960. This may be due to the higher was seen on 26th and 27th April. Another number of pulii (439) ringed. Recoveries first for the Decoy was a Buzzard on 15th reported in 1964 are listed in Table II. A April. On this same day 30 Redwings Bullfinch trapped on 12th January, 1964, settled in the top of an oak and stayed for had been ringed at , Lincs., about an hour. The last recorded Field­ 62 miles north, on 18th November, 1963. fares were three on 19th. Swallows were The weather in January was as open and late (28th), average (20th), and mild as 1963 had been coid. Only one small Turtle Doves early (20th). Swifts on 30th flock of 16 Pinkfeet fed near the Decoy, on April were followed by Spotted Fly­ 16th. Three Bramblings were seen from catchers on 12th May. 22nd to 27th. Fieldfares never reached Most of the summer migrants had left double figures and Redwings were irre­ by mid-September, latest dates being gular, with a maximum of 7 on 10th. Sedge Warbler 3rd, Whitethroat 18th, February showed little difference in the Willow Warbler/Chiff-chaff 24th. Strag­ general pattern except for an influx of 25 glers into October were three Blackcaps Yellowliammers in the last week. Two and five Reed Warblers on 5th. A very late Garganey appeared on the pond for one Turtle Dove was seen on 9th. Long-tailed day only in March. Fieldfares were more Tits made a welcome re-appearance on plentiful towards the middle of the month, 18th September, a small flock of five being 75 on 17th dropping to 15 by 31st. Eyes the first since December 1962, This built

Table I. Birds other than Anatidae ringed at Borough Fen Decoy in 1964

Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec total

Moorhen I I I i I 5 i I 12 Wood Pigeon 2 2 3 4 2 10 4 2 7 Great Tit I 2 II i 9 3 2 4 33 Blue Tit 6 II 2 3 3 n 4 I 32 Song Thrush 2 8 8 22 31 10 15 6 4 14 8 I 129 Blackbird 4 18 43 II 53 15 10 16 17 50 27 5 269 Robin II i 6 3 2 2 3 i 20 Reed Warbler 6 2 II 10 Blackcap 4 6 2 12 9 6 I 40 Garden Warbler 3 6 3 12 Whitethroat 4 7 12 5 2 i 3 1 Spotted Flycatcher 2 7 I 4 1 4 Dunnock I 7 4 1 7 6 8 13 10 5 6 6 I 84 Starling 5 5 3 13 Greenfinch I 6 6 6 I I 15 21 5 22 10 103 Goldfinch 4 3 24 27 21 i 2 6 86 Linnet I I 4 32 48 54 7 II 149 Bullfinch I I 2 3 4 2 5 8 7 33 Chaffinch 12 I 3 I 4 I 9 II 7 8 57 Reed Bunting r 3 IIII 8 25 Tree Sparrow 8 i i 8 36 15 38 20 12 8 3 1 35 I 223 19 others 2 10 8 3 2 i i 6 15 7 5 6 i 7 6

Total 38 64 96 125 181 207 207 1 5 4 85 188 12 4 l ì 1480 Species of which less than 10 were ringed: Stock Dove I, Turtle Dove 6, Cuckoo 1, Great Spotted Woodpecker 4, Swallow 9, Jackdaw 1, Willow Tit 5, Long-tailed Tit 4, Tree-creeper 2, Wren 4, Fieldfare 4, Redwing 9, Redstart 1, Sedge Warbler 9, Willow Warbler 8, Goldcrest I, Brambliing 1, Yellowhammer 5, House Sparrow 1.

44 THE WILDFOWL TRUST Table II. Recoveries of birds other than ducks ringed at Borough Fen reported in 1964

age date date ringed where found recovered movement

Moorhen AJ 32047 FG 21.ir.61 , , Linds. 31.3.64 6m.W. Moorhen AJ 32062 Juv 26.5.62 Elsham, , Lincs. I O .I .6 4 65m.N. Wood Pigeon 3080681 FG 25.1.63 Easton on the Hill, Northants. 23.3.64 iom.W. 3092555 ist W 1.4.63 Ickleton, Saffron Walden, Essex 14.11.64 8om.SSE Turtle Dove 2037512 Pull 6.7.61 Bouliac (Gironde) France 7.9.64 44°54'N, o°3o 'W Swallow A K 87522 Juv 15 -8 .6 3 Maxey, Peterborough 27.4.64 5m.W Blue Tit A K 87802 Juv 10.10.63 Moulton Marsh, Spalding, Lincs. 20.8.64 i2m.NE AH 25219 FG 4.5.64 Haxey, Epworth, Lincs. 2.12.64 62m.NNW Redwing 59128 R FG 24.10.62 Legazpia, Spain 13.1.63 43°03/N. 2°2o'W Blackbird 67542 X ist W 6.1 1 . 60 Dogsthorpe, Peterborough 20.1.64 5m. S Linnet A K 87035 Pull 23.5.63 Malaga, Spain 3.11.63 36°43'N, 4°25'W AH 25032 FG 10.12.63 Elm Park, Romford, Essex 11.1.64 77m. SSE Chaffinch AH25141 FG° 19.3.64 Kenilworth, Warwicks. 22.12.64 57m. WSW

Only recoveries more than five miles distant are listed. There were in addition 7 local recoveries, of 5 species, during the year.

Table III. Nests found in use in Borough Fen Decoy, 1964

number unsuccessful nests successful nests of nests eggs young some complete species found deserted lost lost or died reared success

Mallard I I Moorhen 4 I I 2 Woodpigeon 15 6 I 2 I 5 Turtle Dove 8 2 I 2 3 Swallow I I Great Tit I I Blue Tit 2 II Wren 3 3 Mistlc Thrush II Song Thrush 34 6 6 3 6 13 Blackbird 37 2 9 4 II II Reed Warbler 3 3 Sedge Warbler I I Blackcap 3 I 2 Whitethroat 4 i I 2 Dunnock 10 I 2 2 2 3 Spotted Flycatcker 2 2 Starling I I Greenfinch 15 I 2 4 8 Goldfinch 18 3 2 i 12 Linnet 74 5 10 14 20 25 Linnet/Cuckoo I I Bullfinch I i Chaffinch I 1 Tree Sparrow 35 I 2 7 15 10

Total 2 7 6 25 38 37 72 104

BOROUGH FEN DECOY 45 up to twelve by the end of 1964 which I may be one of the reasons for the increase hope will survive the winter and breed in of 170 records over 1963. This may also be 1965. interpreted as evidence of natural recovery The first winter migrants were 15 Red­ after the winter of that year. A special note wings on ist October and ten Fieldfares on was made of nests containing partly 18th. Peaks of about 60 and 70 respec­ hatched clutches, and details have been tively were reached by the end of the extracted for a Nature Conservancy month, their numbers shrinking to less inquiry into the possible effects of pesti­ than ten through December. cides upon egg fertility. The Decoy was The first of the 276 nests recorded operated in July, a month earlier than (Table III) was a Moorhen with one egg on usual, in order to learn about the dispersal 25th March. This nest was in a tussock of of the Mallard present in summer. This Juncus communis that has provided the first resulted in many late warbler nests being Moorhen nest of the season for the past missed. All flying warblers ringed were four years. Once again it was successful and weighed and measured for a British Trust the young had hatched and left the nest by for inquiry. Blackcaps topped 2ist April. Many of the nest sites in the the list with 52 individual records, 40 Decoy appear to be traditional and this newly-ringed and 12 re-traps.

The assessment by grazing trial of goose damage to grass

J A N E T K E A R

Grazing trials using captive geese form an situation. Ten geese were penned for 6 J important part of the study into the inter­ hours on each plot, giving the equivalent action of wild geese and agriculture which of about 11,000 goose-hours per acre. is being carried out by the Wildfowl Trust. Grazing started at 8.45 a.m. and after Experiments have involved mainly winter- removal from the experimental plots, the and spring-sown cereals (Kear, 1965) since geese were kept overnight in a shed with it was the possibility of damage to these adequate water for washing. Water for crops which most interested the farming drinking only was provided during the community. Grassland trials, in which grazing period. some of the effects of goose grazing were Table I. Yield of grass and clover field simulated by clipping plots with garden grazed by geese in October shears (Kear and Rodger, 1963), indicated that close clipping has no effect on silage Green weight (lbs.) Dry Matter (%) yield provided that it is not continued Grazed Control Grazed Control beyond the end of March. Thus it seemed that some loss of herbage during the winter October 5th 49 30 1S-5 17-7 was unimportant. However, a number of 6th 37 40 195 i8-r farmers’ complaints concerned the early 7th 33 3« 15-5 17-7 grazing of undersown grass soon after Average 40 36 17-8 17-8 harvest when it was claimed that the geese rather than grazing actually pulled up the The spring barley was drilled on 4th grass by the roots. During early October April, 1964, undersown with a grass and 1963, therefore, a grazing trial using a clover mixture* on 15 th M ay and harvested captive flock of Pinkfeet and Greylag Geese on 6th September. Grazing covered the was run on a young ley at Rosemaund period 5th-7th October and on the first and Experimental Husbandry Farm in Here­ last grazing days there was rain. The geese fordshire. obviously found the grass palatable, but The experiment was set up so that the only the slightest ‘damage’ by trampling trial contained one grazing treatment and could be seen on the wet days. Uprooted one control and was replicated three times. plants scattered on the surface, or patches The procedure was that given in Kear of bare earth from which plants might have (1965): the randomly arranged plots been pulled, were entirely absent at the measured 8-5 feet (13 drill rows) X 30 feet, end of each grazing period. Table I gives or 1/171 of an acre. From field observa­ the yields of the plots on 22nd May, 1964, tions it appears that 9,000 goose-hours on and shows that no statistical difference the same acre is maximal in any season and could be found between the harvests from a goose usage rather greater than this was the grazed and control areas. Thus it therefore the aim in the experimental appears that, even with very high grazing

46 THE WILDFOWL TROST usage, geese need cause no damage to * 5 1b. 2 23 Ryegrass (perennial) young grass in early autumn. 5 1b. S 24 a, 3, 5 1b. S 101 „ „ It is a pleasure to thank the staff of the 4 1b. S 48 Timothy Rcsemaund Experimental Husbandry 4 1b. S 215 Meadow Fescue Farm at Preston Wynne, Hereford, for 2 1b. S 123 Red Clover their assistance in the running of this trial. I 1b. S 100 White Clover

References

K e a r , j. 1965. The assessment of goose damage by grazing trials. Trans. 6th Int. Union Game Biol. KEAR, J. and J . B. A. RODGER. 1963. Wild geese i n east Scotland. Scot. Agrie. 43: 123-126.

The reaction of captive Mallard to grain treated with a commercial bird repellent J A N E T K E A R

Wildfowl predation presents a very minor Methods problem to agriculture as a whole in Wheat grain was selected for testing be­ Britain, and only at certain times and in cause it is known to be preferred to other certain places does it become necessary to cereals by both tame and wild-caught limit their activities (Kear, 1963). It is Mallard over short periods (Kear, un­ recognised that the application of a sub­ published data). The birds were kept in stance to a crop which will render it pairs (a male and a female together) in unattractive but not kill would be very separate cages and fed on a mixed diet of advantageous, but the study of chemical wheat, rusks and commercial poultry protection against birds is still in its early crumbs, with water and grit always avail­ stages. A variety of substances relying on able. In their daily test regime, the ducks the sense of taste, smell, touch or pain has had a dish of mixed food over night and been tried unsuccessfully with ducks in for part of the day, but for six daylight America (Neff and Meanley, 1956); whole hours they were offered only wheat grain. barely soaked in gum turpentine and in For a preliminary period, this grain was kerosene was completely eaten and the untreated, and for the following two weeks commercial American repellent Pestex, the birds had a choice of treated and un­ dusted on to the grain, did not even slow treated grain from two similar containers, down the birds’ feeding rate. However, the position of which was altered at Neff and Meanley (1957) and Neff, random. For the next two weeks they were Meanley and Brunton (1957) claimed offered only treated grain in both dishes and consistent success against grackles, cow- during the final fortnight they returned to birds, redwings and other birds when the choice situation. The treated sample anthraquinone was used at heavy levels. was prepared by mixing xo kilos of wheat Later, Duncan (1963) reported the reac­ with i pint of Morkit ‘solution’, made up tions of feral pigeons to seven active as directed on the packet (about 1-7 gms ingredients of commercial repellents in dry weight of Morkit to 10 kilos of wheat). solution. All solutions, with the exception This amount of liquid effectively wetted of anthraquinone, produced a significant the surface of each grain, which was sub­ reduction of fluid intake and ß-naphthol sequently dried in warm air. The control was markedly rejected. Duncan pointed wheat sample was moistened with one pint out that, although insoluble anthraquinone of tap water per ten kilos and also dried. showed no repellent action when tested in this way, this does not mean that it is Results valueless when used as a powder. Anthra­ During the first two weeks of the test the quinone (a harmless, yellow crystalline ducks consumed on average 15-7 gms per ketone, C 6H,(CO)2C8H4) is in fact a basic bird per trial period, and of this only 25-2 ingredient of a German-made bird repel­ per cent during the first week and 23-6 lent marketed in Britain as Morkit. At the per cent during the second week was of the Wildfowl Trust, a few preliminary tests treated wheat grain. During the third and have been made in which four caged hand- fourth weeks, when only treated grain was reared Mallard were offered grain treated available, the birds reduced their intake with Morkit. and consumed on average 5-9 gms and 4-6

COMMERCIAL BIRD REPELLENT 47 gms respectively per bird per trial period. caged birds normally prefer uncontami­ In the last two weeks the Mallard took on nated food with which they are familiar average 13-3 gms per bird per test period, whatever the contaminant (Neff et al., and 7'9 per cent during the fifth week and 1957)3 and a true repellent must satisfy only 3-1 per cent during the sixth week was two paramount requirements : it must repel of the grain treated with Morkit. even hungry birds, while not being toxic to plants nor harmful to structures (Dun­ Discussion can, Wright and Ridpath, i960). W ith It appears from these few experiments that wildfowl, however, the problem is often Morkit, even at low concentrations, will not to remove the birds altogether but to repel ducks that are not particularly persuade them to feed in places where the hungry. What it is that the birds dislike damage they can do is negligible. Sub­ about anthraquinone is uncertain. To sequent, more important trials will assess humans it is tasteless, though producing a the value of anthraquinone when sprayed rather odd sensation in the mouth as an on to selected areas of grass in an effort to after effect. It must be pointed out that control the grazing of geese and swans. References DUNCAN, C. J. 1963. The response of the feral pigeon when offered the active ingredients of co m ­ mercial repellents in solution. Ann. appi. Biol. 51: 127-134. DUNCAN, C. J., E. N. Wr ig h t and M. G. RIDPATH. i960. A review of the search for bird-repellent substances in Great Britain. Annales des Epiphyties, No. hors serie: 205-212. KEAR, J . 1963. The protection o f crops from damage b y wildfowl. Wildfowl Trust 14th Ann. Report : 66-71. Ne f f . J. A. and E. m e a n l e y . 1956. Research on bird repellents. Progress report No. 1. U.S. and Wildlife Service, pp. 1-13. Ne ff, j. A. and b . m e a n l e y . 1957. Research on bird repellents. Progress report No. 2. U.S. Fish and Wildlife Service, pp. 1-21. Ne ff, j. A., B. m e a n l e y and R. B. b r u n t o n . 1957. Research on bird repellents. Progress report No. 3, part I. U.S. Fish and Wildlife Service, pp. 1-19.

Wader ringing by the Wildfowl Trust, 1959-64

M. A. OGILVIE

In August 1959, the Wildfowl Trust’s pact flocks on suitable fields, usually rocket-netting equipment was successfully choosing ploughed land or fields with very used to catch waders on the south shore of short vegetation. It was this habit that was the Wash. The initiative for this operation first observed and then taken advantage of came from Dr. C. D. T. Minton and other by the Wash Wader Ringing Group using ringers under the collective name of the the rocket-nets. The catching was all done Wash Wader Ringing Group. Although in daylight, the tides sometimes giving us the rocket-nets were designed for catching two chances in a day, more often just one. geese and had, apart from occasional sorties In each of the five years 1959-1963 after ducks, been used exclusively for this catching operations were carried out for purpose, the equipment required no modi­ one or two periods of a week, between July fication in kind for wader-netting. The and September. At this time of year rela­ greatest single obstacle to catching waders tively few suitable fields were available as with nets thrown over them, as opposed to roosting sites, making the choice of where flight-netting, is finding suitably hard to set the nets a little less difficult. The ground, frequented by the birds and pre­ technique improved with experience but a ferably not ever covered by the tide, on number of important discoveries were which to place the nets. The topography made early on. Unlike geese, many waders of the Wash with its areas of salting and do not lie quietly when caught by the net mud in front of the sea-wall and large and it was necessary to cover every bird fields behind provided the answer. During with blackout material immediately after normal high tides the waders are driven off firing the nets. This done, the birds were the mud-flats, over which they feed, on to extracted and placed in the hessian keeping the saltings. Here they roost until the water cages. Here they sat quietly until ringed has receded. During periods of spring and released. It was learnt very soon that tides, however, the saltings are generally two rocket-nets of | acre each cover very completely covered and the birds then fly little of a field which may be up to 110 over the sea-wall and roost in large, com­ acres in area. However if, as not infre-

48 THE WILDFOWL TRUST Table I. Ringing totals and recoveries of waders caught on the Wash 1959-1563.

RECOVERIES Recovered Britain Total rate outside local local species ringed total % abroad Wash dead recaps Oyster-catcher 207 7 3-38 I I 2 3 Grey Plover 417 3 0-72 I 2 Turnstone 302 3 0-99 I 2 Curlew 235 24 10*20 2 2 19 i Bar-tailed Godwit 72 2 278 2 Redshank 934 31 3-32 2 13 16 Knot 3157 29 0-92 7 IO 5 7 Dunlin 7560 38 0-50 22 3 3 10 other species* 32 - - Total 12916 137 I-OÓ 35 29 50 23

* Also ringed, no recoveries :— Ringed Plover 2; Golden Plover 1; Whimbrel ij Black-tailed Godwit 7j Curlew Sandpiper 7; Sanderling 14.

auently happened, the waders landed out­ other extreme, Curlews and Godwits were side the catching area, it was possible to only driven off the saltings for perhaps the move the flock either all together or bit by three or four highest tides in a week and bit in the desired direction by driving them for one or two hours each time instead of very gently with a slow-moving vehicle or four or five. Efforts, not always successful, sometimes a single person on foot. were directed, especially in the last two Mounted decoys were used, as in goose- years, towards catching species other than netting, to attract the birds to the catching Dunlin. Ringing large numbers of Dunlin area by the nets. The best possible decoys, just because it was possible to do so was again as in goose-catching, were small placed second to deliberate attempts to flocks of birds landing in the catching area catch Knot, Bar-tailed Godwit and Curlew, before the main flight over the sea-wall three species which have not been ringed began. During the late summer and early on quite the massive scale that the Scandi­ autumn the numbers of waders in the navians in particular have marked Dunlin. Wash are quite high; not infrequently Only Knot were caught in large numbers, 5-10,000 waders roost in a single close- with smaller though useful catches of packed flock on one field, and there may Oystercatcher, Grey Plover, Turnstone, be three such flocks roosting along the Curlew and Redshank. 15-mile south shore of the Wash. As in every type of catching operation, failures Results from ringing or part-failures always tend to predomi­ Set beside the expected reporting of nate, so that the totals caught in one throw I5~25% °f ducks and geese ringed, the of the nets range from under 100 (often) to recovery percentage of waders is low (1%). 2,200 (once). Only very occasionally were Even among the species that may legally be both nets fired at once, the almost invari­ shot in most of the countries they visit, able practice with geese, because it was returns are meagre. Table II records all thought possible that between them the the recoveries so far reported outside the two nets might one day catch more birds British Isles. than could be safely and conveniently Oystercatcher managed. A large team of ringers, skilled The single overseas recovery is the second in handling and ringing birds with care and British-ringed Oystercatcher to reach speed, was always present and with even Morocco. It is known from other ringing the largest catch was not overwhelmed by (Buxton, 1957) that there is a regular the numbers involved. migration from Britain down the west As Table I shows, Dunlin were caught coast of France into northern Spain with a in much greater numbers than any other few birds reaching Portugal, south Spain species, because they were most plentiful and the north coast of Africa. as well as being the easiest to catch. Other Three Oystercatchers marked on the species were not so tolerant of being moved Wash in early August have been recaught around a field, and, as one of the smallest breeding there in subsequent years. species, the Dunlin were the first to be affected by the rising tides so there was Grey Plover always a longer period and more days when So far the ringing in 1963 of 383 of this they came over the sea-wall to roost. At the species, rather more than three times the

WADER RINGING 49 number previously marked in Britain, has of ringing, indicating a strong attachment provided a single recovery in Morocco, the to winter-quarters. only one away from the Wash. This bird fits in well with the pattern of recoveries Bar-tailed, Godwit from over 500 Grey Plover ringed in The two recoveries are both local, one and Denmark and Norway. These birds, two years respectively after ringing. From breeding it is thought in Siberia, migrate European ringing, the origin of the winter­ through western France to Africa, one bird ing birds in Britain is northern Eurasia reaching 6°N by early October (Narrevang, (Norrevang, 1959). 1959). Redshank Turnstone Ogilvie (1963), using recoveries of British- There have been just three local recoveries ringed Redshank notified to the end of of Turnstone, two of them a year after 1962, concluded that, while the local marking. Other ringing has shown (Nor- breeding stock moves south and west in revang, 1959) that the breeding populations autumn, the wintering population in from Greenland and Ellesmere Island and Britain, comprised largely of birds from from northern Scandinavia and Russia Iceland, is fairly sedentary throughout the migrate to western Europe and south to winter months. The exceptionally severe west Africa. weather during the early part of 1963 caused many birds to leave Britain and Curlew decimated those that remained. Pilcher The two foreign recoveries confirm the (1964), writing about the effects of the continental origin of Curlew wintering in cold on the north coast of the Wash, lists Britain. A single recovery on the Severn 144 corpses of Redshank found in one week estuary is possibly an example o f the known at ¿tie end of February. 14 recoveries were onward passage of some birds through reported during the cold spell including England, some going to Ireland, others to one in France and seven others over 50 western France. Over half the local miles from the Wash. In the autumn of recoveries were in years subsequent to that 1963, Redshank were still very scarce on

Table II. Overseas recoveries of waders caught on the Wash 1959-1963

Ring number date ringed age cause of death recovery locality recovery date

Oystercatcher A T 83155 17.8.62 Fg shot Near Bouznika, Morocco 16.12.62 (33D49'N 7°lo'W) Grey Plover D S 14153 6.9.63 Ad caught El Merja region, Kenitra, Morocco 14.3.64 (34°25'N 6o30'W) Curlew A T 83036 28.8.61 Ad shot Hojer, Jutland, Denmark 3.8.64 (54°58'N , 8°48'E) A T 83042 28.8.61 Ad found dead Söderveckoski, Borgä, Usuimaa, 6.7.64 Finland (6o°23'N, 25°25'E) Redshank P 10005 18.8.59 Ad killed St. Martin de Brehal, near Coutances, I3-I-63 Manche, France (49°03'N, i°27'W) P 19404 29.8.61 Juv killed St. Marie du Mont, Manche, France 21.11.61 (49°22'N, i ° I 4 'W ) Knot 7342S2 17.8.62 Juv shot Crown Prince Island, Disco Bay, 8.6.64 Godshavn, West Greenland (69°oo,N, 53°2o'W) 734389 3.9.63 Juv ? dead Igdlerssuit, Umanak, West Greenland, 28.6.64 (7i° i5'N, 53°25'W) CX 25424 3-9-63 Juv caught & Borni Hills, Liberia (6°55'N, io°55'W) 11.9.63 killed CX 25719 3.9.63 Juv killed Lake Malika, 20 kms from Dakar, 29.9.63 Sénégal (i4°38/N, I 7° 27/W ) CX 26635 6.9.63 Juv killed M ’Boro, near Tbies, Sénégal 25.9.63 I 4 ° 4 9 /N , i 6 ° 5 2 'W ) CX 26864 6.9.63 Juv killed M ’Boro, near Thies, Sénégal 25.9.63 (I4°49'N , i 6°52/\V) CX 27680 6.9.63 Juv killed Lake Tamna, near Kayar, Sénégal 13.10.63 (i4°53'N'j I 7 ° 2 4 'W )

SO THE WILDFOWL TRUST Table II. Overseas recoveries of waders caught on the Wash 1959-1963-continued'

Ring number date ringed age cause of death recovery locality recovery date

D u n lin 624034 18.8.59 Ad shot Near Hoibaek, Sjaelland, Denmark 20.8.61 (55°43'N , h ° 44'E) 624167 18.8.59 istw killed Baie de Gouiven, near Plouneour, 31.7.62 Finistère, France (48°38/N, 4°I9'W) 624803 18.8.59 Ad shot Rammu Island, Harju, Estonian IO.8.61 S.S.R. (59°35'N, 25° i3'E) 627010 9.8.60 Ad ? dead North shore of Ringkobing Fjord, 0.8.61 Jutland, Denmark (s ó ^ 'Ñ , 8°I5'E) 627372 II.8.60 Ad found dead Octeville, Seine Maritime, France 25/29.3.62 or killed (49°33/N, 0o07'E) 627403 II. 8.60 Ad shot Vallensbaek, near Taastrup, Sjaelland, 15.8.61 Denmark (55°36'N, I2°23'E) 622747 26.8.60 Ad controlled Amager, Copenhagen, Sjaelland, 18.8.61 Denmark (55038'N 3 I2°34'E) 622908 26.8.60 Ad killed Póvoa de Santa Iria, near Loures, c.1.2.62 Estremadura, Portugal (38°5o'N, 9°io'W) 61309 S 25.8.61 Ad caught & Santa Iria, near Loures, Estremadura, c.25.12.62: killed Portugal (38°5i/N, 9°05'W) 61556 S 29.8.61 Ad found dead Manslagt, near Emden, Niedersachsen., 16.6.62 Germany to^ T S T , 7°o8'E) 61661 s 29.8.61 Juv killed Near Severodvinsk, Arkhangel, 19.5.63 U.S.S.R. (64°32'N, 39°55'E) 639521 17.8.62 Ad controlled Skanör, Skâne, Sweden 23/25.7.64. (55°25lSr, i6°24'E) 639488 19.8.62 Juv killed Audenge, Gironde, France 21.9.62 44°4o'N, i °o i 'W) BA 48030 7.8.63 Ad killed Puerto Real, Cadiz, Spain c.23.2.65 (36°32'N, 6°i i 'W) BA 48517 7.8.63 Ad killed Figueira da Fez, Beira Litoral, 22.9.63 Portugal (40°09'N, 8°5i 'W) BA 4813- 4/5.9.63 Fg found dead Grève de FEpois, Baie de Bourgneuf, 12.5.64 Vendée, France (47°02'N, 2°oo'W) BA 49788 6.9.63 Ad killed Baie de Mont-St.-Michel, Ille et I5-3-64 Vilaine, France (48°38'N, i °3o'W) BA 49822 7.9.63 Ad controlled Aflandshage, Amager, Sjaelland, 6.8.64 Denmark (55°33'N, I2°36'E) BA 4989- 7.9.63 Ad shot Figuiera da Foz, Beira Litoral, 23.9.63 Portugal (40°09/N, 8°5i 'W) BA 50034 7.9.63 Ad controlled Amager, Sjaelland, Denmark 9.8.64 (59°38'N, I2°34'E) BA 50046 7.9.63 Juv killed Baie de l’Aiguillon, Vendée, France II. 11.63 (46°i8'N, i ° i 5'W) the Wash and only 12 were caught com­ showed that birds from Arctic Canada and pared with the previous four years’ total of Greenland, and from Siberia, come to- over 900. western Europe, with many passing: through on their way to Africa. The cap­ Knot ture of 2,000 K not on the W ash in Septem­ The breeding distribution of this species ber 1963 has produced as yet very few, but described by Kozlova (1962) is both wide­ very spectacular recoveries, especially those spread yet discontinuous, with colonies on from West Africa showing an extremely Victoria Island, Melville Island and Elles­ rapid onward passage. In just eight days, mere Island in Northern Canada; north­ one bird was killed in Liberia, 3,300 miles west, north and east Greenland; probably to the south. Other recoveries were some in Spitsbergen; and the Taymyr reported from Sénégal, two within three Peninsula and Novosibirskiye Islands in weeks of ringing and two more before five Asian Russia. Wintering is recorded from weeks had passed. All these were juveniles the Caribbean, the west and east coasts of that had already travelled considerable South America; western Europe, equato­ distances from wherever they were bred. rial West Africa, and Angola; the west and The only evidence as to the origin of the east coasts of Australia, and New Zealand. Knot ringed on the Wash comes from two From ringing in Scandinavia, where over recoveries in west Greenland. There is a 3,000 have been marked, Norrevang (1959) definite movement through Britain to.

WADER RINGING 5 1 Ireland, possibly of birds of a different However, a much greater advantage is stock. Others winter in the Wash, as shown gained by having records over five years by nine local recoveries and recaptures in covering the whole of the period from mid- the same season of ringing. July to early September. Thus it has been possible to study the variation of age-ratio Dunlin with date, and the timing and speed of the As mentioned above, this was the easiest wing-moult. Full results of this work are bird to catch and, although efforts were being written up and will be published made to catch other birds instead, more elsewhere in the near future. Dunlin were caught each year than any other species. The total of 7,500 ringed Foreign-ringed birds caught on the is less than half the number marked in Wash Scandinavia since the war. Ogilvie (1963), Many Dunlin ringed on passage in Scandi­ using recoveries notified to the end of 1962, navia have been recaptured each year by showed that winter visitors to this country the rocket-nets at the Wash. They were come from Scandinavia and Russia, and marked in Finland (2), Sweden (25), also from Iceland with a certain amount of Norway (7), Denmark (5), Heligoland (1). autumn passage through Britain of both Two others ringed in May in eastern Fin­ stocks to areas further south. The recoveries land and in June on the Great Ainov since then have not altered this picture. Islands in the White Sea were probably From recaptures and recoveries it is known breeding birds. that Dunlin arriving on the Wash as early A single Turnstone ringed on passage in as mid-July may stay there the whole south Norway was caught at the Wash in winter, whilst passage-migrants continue September 1963. to pass through for a further two months or more. Over 200 Dunlin have been Other wader-ringing undertaken with recaught in subsequent seasons and these the Trust’s rocket-nets have shown that there is a marked tendency The Dee, Cheshire for birds to return not only to the Wash In September 1961 a Trust team joined itself, but to a particular part of the coast. with Dr. E. White of Liverpool University The main catches of Dunlin have been in an attempt to catch Oystercatchers on made in two areas either side of the mouth the Dee estuary. A single catch of 151 was of the River , only seven miles apart, made on the Welsh side of the Dee, after but the number of birds recorded as several frustrations and disappointments moving from one roost to the other even on the islands off the north shore. Dr. after three or four years is less than one- White subsequently developed his own sixth the number recaught at the ringing equipment and is studying the waders of place. Such strong attachment to discrete the area. The Oystercatcher has now areas away from a nesting place had not become the subject of an intensive study previously been met with in waders, by the Ministry of Agriculture, Fisheries though well known in wildfowl. and Food who are using their own design Age-ratios, moult, weights and meas­ of cannon-nets. urements Vlieland, Holland Whilst it was always the aim to extricate, A Wildfowl Trust rocket-netting team ring and release the birds caught as expe­ visited Vlieland from 3rd to n th Septem­ ditiously as possible, the opportunity was ber, 1964, at the invitation of Dr. A. C. taken to examine as many as was practi­ Perdeck, Director of the Vogeltrekstation, cable and to collect such information as the a division of the Instituut voor Oecologisch age, state of wing-moult, weight and Onderzoek, Arnhem, to discover whether various measurements. With a small catch the equipment could be used successfully and plenty of people every bird could be to catch some of the very large numbers of examined in this way, but only a sample waders frequenting the island in late could be taken of the larger catches. The summer and autumn. Members of the age and state of primary-moult was com­ W.W.R.G. also took part, together with paratively simple and quick to record at the members of the staff of the Vogeltreksta­ same time as ringing each bird and con­ tion and representatives from Germany and sequently more data of this kind were Belgium. Catching operations began on gathered than from the more detailed and 4th when a net was set by a small fresh­ time-consuming weighing and measuring. water stream crossing mud-flats visited by Because the timing of the catching trips many Shelducks in order to drink. A catch each year depended on the spring tide of 61 was quickly made. A second catch of periods, the dates varied widely and direct 31 was made on 7th, when the ducks were comparisons from year to year are invalid. noticeably more wary.

52 THE WILDFOWL TRUST Table III. Birds cau g h t on Vlieland., September 1964

Species Total Species Total

Shelduck 95 Greenshank 2 Oystercatcher 2 Knot 2 Ringed Plover 5 Purple Sandpiper I Kentish Plover I Dunlin 8 1 Turnstone 349 Curlew Sandpiper I Redshank 486 Common Gull 15 Spotted Redshank I Black-headed Gull m

total catch 1 1 5 2

The first catch reassured us that the what had promised to be a notable haul of equipment could be used in very wet waders. The Vliehors could not be used conditions, the rockets firing well despite after 7th because of the resumption of immersion in sea-water. Thus, in the target-practice by tanks, which caused the absence of any promising assembly of birds to leave. resting waders on dry land, it was decided On 8th one net was set in a small grass to set both nets on a sandy shore close to field being used as a roost by gulls and a high-water mark for a catch on the morning few Oystercatchers and the second net was tide of 5th. In the event, the tide covered set in a very small field very close to the the nets as well as the rockets with over 6 village of Oost-Vlieland. The first field inches of water and no large concentration proved useless, perhaps because the of waders in the catching area was achieved, earliest-arriving birds found setting in despite great activity as the tide began to progress, but a catch of Turnstones and ebb. The nets were not seriously displaced gulls was made near the village. by the tide. A catch of 89 was made in one The only dry site remaining to be net, nearly all Dunlin. Attempts on the exploited was a large Curlew roost on succeeding days to move the large numbers dunes inland. This posed considerable of Knot, Dunlin and Bar-tailed Godwit in problems in setting, because it was hard to this area confirmed that they were not find space to set both nets and impossible prepared to sit on dry land at high water, to see the area adequately from a safe which was essential before they could be distance. On the afternoon of 8th the nets caught. were set in a T-shape, with a firing-point From 5th onwards the evening tides within 40 yards of and almost in line with were too late for catches to be made before the end rocket of the nearer net. Much time dark. For the morning of 6th the nets were was spent in covering the nets, which set on the sand flats of the Vliehors, an remained uncomfortably conspicuous for area used by several thousand Oyster­ such wary birds as Curlew. On the morning catchers. The shore there is so gently of 9th several thousand Curlew and Bar­ shelving that accurate prediction is very tailed Godwit settled in the vicinity, but difficult, if not impossible: the tide rose fewer than a hundred sat in the catching higher than expected, the nets were carried area and no build-up could be achieved, over the rockets and pieces of driftwood despite many efforts at moving the birds. also settled across the nets, so that they could The nets were removed and set in a wet not be fired. Continued attempts to drive field close to the team’s base at Het Post- Oystercatchers into the catching area failed. huis which had come belatedly into favour For the tide of 7th the nets were moved with waders, especially Redshanks, and up the sand flats to a point most unlikely gulls. The nets were set in tandem to fire to be inundated. It was necessary to move down-wind and disguised. A catch of the Oystercatchers a long distance to bring nearly 800 birds was made in one net. them into the catching area. This was This international exercise was ex­ achieved very successfully by herding them tremely stimulating to everyone who took in front of the Land Rover, Oystercatchers part. We are most grateful to Dr. A. C. being exceptionally willing to walk or run Perdeck for bringing it about, for securing and unwilling to fly during their long high- financial support and for his generous and water resting period. Unfortunately, just successful arrangements for the visitors. as the first birds had entered the catching It is perhaps not invidious to express area, a low-flying aircraft proved too great particular satisfaction at the presence of an additional stimulus. A small catch of J. P. van de Weghe, of Vogelringstation gulls was inadequate compensation for Braakman, and F. Gräfe, of Vogelwarte

WADER RINGING 53 Helgoland, not merely as representatives buting notably to such success as was of Belgium and Germany but for contri- achieved. References b ü x t o n , E. J. M. 1957. Migrations of the Oystercatcher in the area of Britain: results from ring­ ing. Brit. Birds 50: 519-524. K o z l o v a , E . v . 1962. Fauna of the U.S.S.R. : Birds, Vol. 2, section 1, part 3. 433 pp. Moscow. (In Russian.) N0RREVANG, a . 1959- The migration patterns of some waders in Europe, based on the ringing results. Vidensk. Medd. Dansk Naturh. Foren. 121: 181-222. OGILVIE, M. A. 1963. The migrations of European Redshank and Dunlin. Wildfowl Trust 14th Ann. Report'. 141-149. PILCHER, R. E. M. 1964. Effects of the cold winter of 1962-63 on birds of the north coast of the Wash. Wildfowl Trust 15th Ann. Report: 23-26.

Nests and eggs of Greylag Geese in Galloway J. G . Y O U N G Sum m ary Sixty eggs in 10 nests of Greylag Geese in Galloway in 1964 were measured. Their dimensions (average length 84-5 mm., breadth 59-2 mm.) were similar to those published for other British eggs which tend to be smaller than eggs from continental Europe. All 10 nests were successful, though 5 eggs failed to hatch. In a second group of nests, 6 out of 8 clutches were successful. At least 42 goslings were reared in the first group and 28 in the second. The sites and dimensions of the nests are described. Introduction large rocks, two in dense secondary growth In recent years Greylag Geese Anser anser and one on open ground. In a group of four have been increasing and spreading as on one island, the nearest nests wrere six breeding birds in south-west Scotland. The feet apart and the furthest forty-five feet. increase is probably due largely, though The average diameter of the nests was 26 perhaps not wholly, to ‘overspill’ from the inches, with a rim of 3-f inches and a cup flourishing feral colony on the estate of the inches deep. Earl of Stair near Stranraer, Wigtown­ Clutch-size shire. The study area, a loch and its environs, was first used by a single pair in Three single eggs were found deposited in 1951. In 1952 seven adults and five gos­ positions where there was obviously no lings were seen on 29th June. In 1953 31 nest. The clutches in the ten nests were geese were counted, of which only ten or distributed as follows : twelve were adults. In 1957 there were 20 clutch-size 45679 adults with seven broods. The breeding number of clutches 22231 stock does not seem to have increased beyond this point, ten nests having been The mean clutch-size, excluding the single found in 1963 and again in 1964. The area eggs, was 6-0. This is rather larger than is also used as a moulting place, counts of would be expected from the note by over 150 geese in early June being not F. C. R. Jourdain (in Witherby, Jourdain, uncommon. Ticehurst and Tucker, The Handbook of This paper is concerned with the ten British Birds, III, 1939) ‘Eggs:— Number nests of 1964, with the dimensions of the variable; usually 4 to 6, occasionally 7 or 3 60 eggs they contained, and with the only, rarely 8’. Two pure white eggs were success of this and another group of nests seen in different clutches, in which the rest elsewhere in Galloway. of the eggs were stained. The white eggs hatched at the same time as the other eggs Nests so must presumably have been incubated All the nests were built on islands. They for the same period. were built on the ground, of large twigs, withered grasses and moss, and contained Hatching success considerable amounts of down. In two All the nests were successful in producing nests examined twig by twig on different young. 55 of the 60 eggs (91-7%) hatched, islands there was no evidence of material the five that failed to do so occurring in having been carried to the nest. Most of the five different nests. The clutch of nine in nests were near the water’s edge. Five were nest VI all hatched and a brood of nine at the bases of large trees, three beside w7as later seen on the loch.

54 THE WILDFOWL TROST There were eight nests in another group The egg weights are summarised in in Galloway. These were not studied in de­ Table II. Eggs with well-incubated em- tail but it is known that two clutches failed ryos weigh substantially less than those to hatch, at least one being deserted. of freshly-laid eggs. It seems likely that much of the relatively large differences in Fledging success egg weights between clutches can be The exact number of goslings that lived to attributed to differences in the elapsed fly is not known but in the principal study times of incubation, rather than to differ­ at least 42 were still alive on 28th June. On ences in egg volume. the same day there were at least 28 sur­ vivors from the six successful nests in the Moult second group. A total of 286 birds moulted in these two areas, 75 on the main study and 211 at the Eggs second locality. The eggs were measured on 25th April, ten days before the peak of hatching. The Acknowledgements linear measurements are summarised in To ensure that the minimum amount of Tables I and II. The mean length and time was spent at the nests I had the breadth agree very closely with those of the assistance of Len Allison, James Morrison, collection of British eggs measured by George McMurdo and Robert T. Smith. Jourdain (Witherby, et al., 1939). From Sir Geoffrey Hughes-Onslow gave me the published data it seems as if British eggs history of geese in the study area. I am tend to be smaller than those found in especially indebted to Hugh Boyd, Sir Europe but indistinguishable from those Arthur B. Duncan and Donald Watson for collected in Iceland. comments on this paper.

Table I. Length and breadth of Greylag eggs from Galloway compared with those from elsewhere

number length (mm) breadth (mm) locality of eggs mean range mean range source

Galloway 60 84'5 78-92 59-2 54-64 other British xoo 85-32 77-0- 94-4 58-04 49 5- 62-5 (I) Iceland 18 + 84'9 76-92 58-7 53-63 (2, 3) Norway ? 80-92 58 mode 53-62 (3) Denmark 29 90-7 85-95 6i-i 57-64 (3) Russia 51 88-2 79-5- 95-5 60-3 53-5-68-5 (4)

Sources : ( 1 ) F. C. R. Jourdain, in Witherby et al., 19 3 9 . (2) G. Timmermann, 19 3 8 , Die Vogel Islands', P. Nielsen, 1 9 1 9 , Ornith Tids. 1 3 : 3 3 - 7 9 . (3 ) E. L. Schioler, 1 9 2 5 , Danmarks Fugle, I. (4) S. Alpheraky, 1 9 0 5 , The Geese of Europe and Asia.

Table ü. Differences between clutches in the dimensions and weights of Greylag eggs

mean length mean breadth mean weight nest no. of eggs mm mm gm

I 1 87-3 60-7 145-9 II 7 84-4 57-1 148-7 III 6 80-8 60-3 133-0 IV 6 83-8 58-8 147-7 V 5 84-4 55-6 149-6 VI'. 9 84-1 57-8 147-6 VII 4 860 62-3 168-5 VIII 7 87-9 60-7 1610 1X 1 5 84-2 59-4 1536 X " 4 81-8 59 5 1330

Total 60 84-5 592 148-9 range of individual egg weights 122-172 gms.

GREYLAG GEESE 55 Organic chlorine insecticide residues in Goosanders and Red-breasted Mergansers

C. H. W ALKER and D. H. M ILLS

Summary Appreciable quantities of residues of organic chlorine insecticides or their metabolites were found in eleven Goosanders and nine Rea-breasted Mergansers collected in Scotland from March to July, 1964. The levels of contamination with dieldrin, which is very toxic to birds, were in most cases low compared with those reported in other birds feeding on freshwater fish in other areas of Britain. Introduction Results and Discussion Organic chlorine insecticide residues were The results of the analyses for organic shown by Moore and Walker (1964) to be chlorine insecticide residues in the liver present in two fish-eating birds, the Heron are given in Table I. As in other species Ardea cinerea and the Great Crested of bird (Moore and Walker, 1964), pp1 cristatus. The average residue DDE was the most common and abundant concentrations in the breast muscle of these residue found. This compound is a meta­ two species were much higher than those bolite of ppxDD T and there is no evidence occurring in birds of prey such as the that it is biologically active to birds. On Sparrow-Hawk Accipiter nisus, the Barn the other hand, dieldrin is very toxic to O w l Tyto alba, the Tawny Strix aluco birds and Turtle et al. (1963) found 6-2 and the Little Owl Athene noctua. Because to 32 o parts per million (p.p.m.) dieldrin such high concentrations of residue were to be present in the flesh of feral pigeons found in two fish-eating species it was killed with this chemical. Dieldrin in decided to determine the concentrations avian tissues may come from insecticidal present in two fish-eating ducks, the dieldrin, and/or from the conversion of Goosander Mergus merganser and Red­ aldrin which occurs very rapidly after breasted Merganser M . serratus. entry into birds. Heptachlor epoxide is a metabolite of the insecticide heptachlor. Methods With the exception of two Goosanders Liver samples taken from eleven Goosan­ from the Tweed, the levels of contami­ ders and nine Red-breasted Mergansers nation in both the Goosander and the were examined (by C. H. Walker) by Red-breasted Merganser are quite low gas-liquid chromatography (G.L.C.) as compared with those for other birds described by Goodwin, Goulden and feeding on freshwater fish in other areas of Reynolds (1961) and de Faubert Maunder, Britain. Working with breast muscle, Egan and Roburn (1964) and by paper Moore and Walker (1964) found an chromatography (Evans, 1962). The extrac­ average level of organic chlorine insecticide tion and clean-up for these techniques residues of 13-3 p.p.m. (wet weight) in were similar to those described by de seven Herons and 5-8 p.p.m. in four Great Faubert Maunder et al. (1964) except that Crested . As pp'DDT is used a small layer of active charcoal (o-ig) was widely outside agriculture, the source of included in the alumina column when the ppJDDE residues given in Table I is difficulty was experienced with pigmented open to some doubt. Dieldrin and gamma material in the extracts. The G.L.C. BHC may have originated from sheep dips. results were obtained using a Perkin Elmer Samples of Salmon parr, which are 452 gas chromatograph with an Apiezon frequently eaten by both the Goosander column. Where the amounts of pesticide and the Red-breasted Merganser, were were large enough, paper chromatography taken from two Ross-shire rivers, the Meig was used to confirm the results obtained and the Bran and from the upper reaches by G.L.C. Small amounts of pp’D D T and of the Aberdeenshire Dee. They were ppxTD E could not be measured, as break­ analysed for organic chlorine insecticide down of pp’D D T (sometimes with forma­ residues by Mr. A. V. Holden of the tion of ppxTDE) occurred on the Perkin Freshwater Fisheries Laboratory, Pit­ Elmer instrument. Liver samples were lochry, who found that 12 whole parr from taken in preference to breast muscle the Meig and Bran contained respectively samples as higher levels of residues are about 0-020 and 0-003 p.p.m. dieldrin usually found in the liver and it is becom­ (wet weight) and 0-005 and 0-003 p.p.m. ing standard practice to use this organ in ppxDDE. The average amount of dieldrin analysis of birds for organic chlorine plus pp’DD E in 13 fish from the Aberdeen­ insecticide residues. shire Dee was 0-03 p.p.m. (wet weight). In

56 THE WILDFOWL TROST Table ï. Residues of organic chlorine insecticides found in Red-breasted Mergansers and Goosanders in Scotland in 1964. Residue (p.p.m. wet weight) Gamma Heptachlor Locality Date pp1DDE Dieldrin BHC epoxide Red-breasted Merganser R. Conon, Ross-shire 29.4.64 0-70 o-io* R. Carrón, E. Ross-shire 3-7-64 <0-20 R. Tay, Perthshire 6.7.64 r i 33 6.7.64 2-3 0-44 <0-10* 33 6.7.64 0-30 0-04* 33 6.7.64 0-13 33 6.7.64 0-56 0-20* 0-28* 33 6.7.64 2-0 0-20* 0-30* 33 6.7.64 I I 5 0-40* 0-27* Goosander R. Tweed, Berwickshire 26.3.64 9 3 10-2 <0-10* 33 15.4.64 43-0 3-4 R. Orrin, Ross-shire 23.4.64 1-2 R. Garry, Inverness-shire 9.5.64 3-7

References d e f a u b e r t m a u n d e r , M. J., H. EGAN and j . p.o b u r n . 1964. Some practical aspects of the d e te r m i­ nation of chlorinated pesticides by electron-capture gas chromatography. Analyst, Loud., 89: 157-167- DE FAUBERT MAUNDER, M. J., H. EGAN, E. W. GODLY, E. W. HAMMOND, T. ROBURN and J. THOMPSON. 1964. Clean-up of animal fats and dairy products for the analysis of chlorinated pesticide residues. Analyst, Land., 89: 168-174. EVANS, w. H. 1962. The paper-chromatographic separation and determination of chlorinated insecticide residues. Analyst, Lond., 87: 569-575. Go o d w i n , E. s., R. GOULDEN and J. G. Re y n o l d s . 1961. Rapid identification and determination of residues of chlorinated pesticides in crops by gas-liquid chromatography. Analyst, Lond., 86: 697-709. h u n t , E. G. and A. I. b i s c h o f f . i960. Inimical effects o n wildlife of periodic D D D applications to Clear Lake. Calif. Fish and Game 46: 91-106. Moore, N. w. and c . H . w a l k e r . 1964. Organic chlorine insecticide residues in wild birds. Nature, Lond., 201: 1072-1073. TURTLE, E. E., A. TAYLOR, E. N. WRIGHT, R. J. P., THEARLE, H. EGAN, W. H. EVANS and N . M . SOUTER. 1963. The effects on birds of certain chlorinated insecticides used as seed dressings. J. Sci. Fd. Agrie., 8: 567-577.

INSECTICIDE RESIDUES 57 The display flights of Shelduck J O H N H O R I

Display flights have been described for times be heard from the female, accom­ various species of Anatidae, but the flights panied by an infrequent chorus of soft clear of Shelduck Tadorna tadorna have not whistles from the males. The vocalization been noted. Aerial pairing displays are is strongly reminiscent of aerial courtship most frequent in May, with the greatest flights in Wigeon. volume in the first half, although I have Single, unpaired males often fly up to also seen them in other months, particu­ join in aerial displays whilst others some­ larly February and March. As with dab­ times ‘drop out’, planing back to the bling ducks, displays centre on a single marsh in a leisurely way. Flights of up to female and involve varying numbers of six minutes duration have been recorded. males; up to eight have been observed in All the females involved have been sub­ North Kent, but larger numbers may adult: flights are characteristic of the non­ occur. Flights usually originate when an breeding gatherings and are a major part impaired female rises from a fresh water of the pairing displays (see also Hori, Ibis fleet or pool where she has been ‘attended’ 106: 333-360, 1964). by a number of unpaired males. She then Pairing display flights have to be distin­ leads the group in wide circles over the guished from sexual pursuits of mated marsh in a flight which has two main females which also occur at this period. In phases. Initially the female often twists and the latter unmated males, predominantly turns violently, darting into a new direction sub-adults, attempt to break up established or diving steeply. The males follow as pair bonds; such attempts often attract closely as they can and try in turn to further unmated males and violent aerial fly alongside her. For a short time one pursuits can result. However, these never will achieve this position, but then she contain the ‘gliding phase’ and vocaliza­ veers away and another male then attempts tion described above, whilst the aggressive to ‘close’. After this rapid flighting, or nature is quite distinct from the ‘darting’ sometimes between periods of it, a slower phase of the display. Further, the mated and much more graceful display occurs. male invariably defends the pair bond, The group circle and swing leisurely using clashing with other males in mid-air and regular flapping flight interspersed with driving them off. When a single male periods of gliding on characteristically set attempts to break into a pair bond the wings. The ‘cranked’ wings are held very flight is strictly comparable with ‘three- much like those of gliding geese with the bird flights’ of Mallard and Shoveler tips hanging vertically downwards and the (Hori, Wildfowl Trust 14th Ann. Rep.: primaries quivering slightly. As a party of 124-132. 1963); the behaviour of the gliding birds swing overhead a subdued participants is very close to that of Shoveler. running note ‘amk, amk, amk’ can some­

Wildfowl and wildfowling in Bulgaria NIKOLAI BOEV The Zoological Institute of the Bulgarian Academy of Sciences, Sofia

Summary Bulgaria is not very important as a breeding place for wildfowl, because it is too far south, but large numbers stop there on passage in autumn and early spring and considerable numbers remain through the winter in milder years. The drainage of marshes has greatly reduced the habitat available and the construction of hydro-electric reservoirs has done little to offset the losses. The number of wildfowlers in Bulgaria has risen from 36,000 in 1939-40 to 68,000 in 1945-46 and 100,000 in 1964. The kill has fallen from 128,000 ducks and 11,000 geese in 1939-40 to 126,000 ducks and 12,400 geese in 1945-46 and to only 25-30,000 ducks and 4-5,000 geese annually at the present time. In efforts to restore the position the shooting season has been shortened - it is now ist September to 25th March - and a bag limit of ten ducks and three geese introduced. Further restrictions may be necessary, in conjunction with efforts in other countries. Shooting techniques are described. The keeping of Ruddy Shelduck in semi-domestica­ tion was formerly widespread, but the species has decreased greatly. Only five species nest regularly in Bulgaria: the Greylag Goose, Mallard, Garganey, White-eye and Red-crested Pochard. The Greylag has decreased seriously and none of the others are increasing.

58 THE WILDFOWL TRUST ‘After the autumn equinox birds migrate This boundary is determined mainly by from Pontus (i.e. the Black Sea provinces) the availability of unfrozen water where and from the colder countries, wishing to the birds can find food, and partly also by escape the approach of winter. Some of them whether there are places for roosting wander into neighbouring countries, but (Bobrinski 1951). On the assumption that, others make for more distant lands. After the on the way to their winter quarters, birds spring equinox the birds return, on account of need places that are ecologically favourable their fear of the heat. The cranes, for to them, then even up to the present day example, fly from the plains of Scythia (i.e. Bulgaria really answers to their biological from the direction of the Dobrudja) to the requirements. marshes of upper Egypt and from there In the Sofia district the appearance of towards the sources of the Nile. The Pelicans wild ducks and geese depends on the also change their abode. They come from climatic changes. A cool and rainy spring Strimon (Struma) to the Danube, where they usually holds back the migrants. In the rear their young....’ event of a deterioration in the weather, particularly if it turns cold in early spring, Thus Aristotle, more than twenty-two the birds that are on their way north turn centuries ago, sketched in broad outline back. Few large flocks winter for long by the picture of the migration of birds the Danube. They prefer the lakes of the through Bulgaria. Because of its southerly Black Sea coast and the water meadows by situation (the northernmost point is on the rivers in south Bulgaria, particularly in latitude 44°i2'3o" and the southernmost on Thrace. Among the Sofia shooters there is latitude 4i°i4/) and its position near the a belief that when the ‘Serbino’ (as they warm Mediterranean shores, Bulgaria is a call the west and south-west winds) blows, land preferred for migration by many it blows the birds away to the east and then species nesting in the North. On account the migrants hardly ever land. On the of its close proximity to the shores of the other hand, when the ‘Rumunetso’ or Aegean Sea, the presence of the ‘backbone’ ‘Krivetso’ (i.e. ‘oblique wind’, because it of the Balkan Peninsula, the Stara Planina comes from the north-east, from the massif, which keeps it sheltered from the direction of Rumania) blows, it pushes the cold north winds, and of its immediate migrating flocks into the Sofia district and contiguity with the Black Sea, which also then good shooting is expected. But if the has a moderating effect on the winter, ‘Moryak’ (the ‘seaman’) or ‘damp wind’ Bulgaria is not very cold, in spite of the blows from the south or south-west and fact that, to a considerable extent, the brings the warmth of the Mediterranean Rodope Mountains stop the warm south Sea and thaws the ice, the migrants are winds. Almost the whole of northern Bul­ expected to pass quickly through from garia and the greater part of the moun­ south to north almost without stopping, tainous areas have a mean January tem­ since the weather is improving and it is perature below 0 °C. T h e 0 °C isotherm warm. embraces eastern Bulgaria, but the larger areas of southern and central Bulgaria and Conservation problems also the Black Sea coast have a mean In the past Bulgaria was even more favour­ January temperature above 0 °C. T h e able for migration. The flooded areas valley of the Struma and the Pirin district formed by the overflowing of the rivers in have a mean January temperature above their lower reaches (particularly the tribu­ 2°C and the southern part of the Black Sea taries of the Danube and of the Maritsa coast, the part beyond the Strandja Moun­ and the rivers flowing into the Black Sea) tains, has a mean January temperature and the many lakes and marshes formed a above 3°C. Only on the peak of Mussalla diverse and variegated landscape, which in the Rila Mountains is the mean January understandably lured the migrants into temperature as low as —11° C.If we com­ calling here twice a year. And since most pare these data with the biological require­ of these expanses of water were well over­ ments for the wintering of waterfowl, it can grown with hygrophytic vegetation, which be seen that Bulgaria presents itself as a provided the birds with cover in the breed­ suitable annual wintering place, particu­ ing season, a variety of waterfowl nested in larly upper Thrace, sheltered as it is from this country, in numbers undoubtedly the winds, and also the regions by the greater than today. These lakes and Black Sea. As is well known, in Eastern marshes mainly originated in the Quater­ Europe the —6°C January isotherm forms nary age, when subsidences of the earth the eastern limit for occasional wintering of took place, giving rise to depressions of some ducks, but for the majority of species various sizes. At the beginning of this the —2°C January isotherm serves as the century the map of Bulgaria still showed 29 effective boundary of their winter range. large Danubian marshes, 18 large lakes and

WILDFOWL IN BULGARIA 59 marshes situated along the Black Sea coast which varies very much, produces a chang­ and 11 in the interior of the country. Most ing shore line unsuitable for the dense of them have been drained through the growth of water-loving vegetation in which necessity to reclaim new agricultural land the birds could hide and nest. Also the food and in die batüe against malaria. Some of supply in these reservoirs is too poor for them were very large, like the Straldja them to attract ducks except as roosting Marsh in the eastern part of the plain of places. Nevertheless the presence of these Siiven. This marsh, on which pelicans, reservoirs, particularly in western Bulgaria, swans, etc. nested, had an area of about 35 continues to support the migration route sq. km. and was over four metres in depth. which passes through the western part of Others were situated on mountain plateaux, the country. like the Dragoman Marsh, where many The improvement and enrichment of the wild ducks nested. Some of the marshes, lakes with plants that are preferred by such as the Batak Marsh in the Rodope wildfowl during the moult (e.g. with Mountains, on which cranes used to nest, Vallisneria sp., Water Chesnut Trapa still exist, but not in their original state. natans, Duckweed Lemna lemna, Wild Rice The Mandra Marsh has been altered and Zizania aquatica, etc.) has not yet been the White Pelicans, which up to thirty years attempted in Bulgaria, nor have biotech- ago nested there, have been banished. Now nical measures for assisting nesting, such they visit it only sporadically in large as the preparation of artificial nesting wandering flocks. The draining of some of boxes, either floating or standing on piles, the lakes in the eastern part of the country and the creation of other suitable nesting is envisaged in connection with the in­ places for ducks, been applied. There are, creased construction of holiday resorts. however, limitations on the gathering of This could deprive us of the last suitable reeds, the stalks and leaves of which are places of refuge where some interesting used to produce various woven articles and species of wild ducks and geese still nest. rough matting. Where this gathering is These are also essential resting places for necessary, periods in the autumn and win­ waterfowl, following the line of the Black ter are set aside for it, so that it does not Sea migration route. hinder the settling of the birds in the Three of the breeding places of marsh spring. The former savage burning of the and water birds still existing in the last ten dry reeds in early spring is now strictly years, the Pomorie Marsh, the Mandra forbidden, but the clearing from the banks Marsh near Burgas and the inner part of of the lakes of the salt-loving and sand- Lake Varna (the part not made salty by the loving vegetation with a view to improving channel to the Black Sea) are not nature the numerous holiday resorts, as well as the reserves. Only the Srebuma reserve, in the already increased visits of holiday-makers Silistra district near the Danube, is pro­ to the Black Sea coast, have an unfavour­ tected by statute on account of the Dalma­ able influence on some species, particu­ tian Pelicans and other marsh birds nesting larly the Shelduck Tadorna tadorna. T h e there. However, it has been cut off from cutting down of the old hollow trees which the Danube by the draining of the con­ contained suitable nesting holes and in necting channel and this prevents the water general the reduction of the old self-sown from being renewed and so hastens its forests by the shore restricts both Tadorna choking up and eventual doom. We hope tadorna and the Ruddy Shelduck Tadorna that, thanks to the co-operation of the ferruginea in their choice of habitation. International Council for Bird Preserva­ Among the unfavourable factors might tion, we will be able to join in the M.A.R. also be mentioned the turning of herds of scheme to make possible the provision for pigs on to the marshes to feed, which the future of more suitable places for the undoubtedly has a bad effect on the nesting and resting of waterfowl. broods of water birds and waders nesting At the present time a great hydroelectric on the ground. In most of the lakes by the construction programme is being carried Danube and the Black Sea, fishing is out. Over 23 large reservoirs with areas of carried out on a large scale and this also over 1,000 decares (250 acres) have been disturbs the birds which inhabit those built. For example, the Isker Reservoir lakes. In spite of the purification plants near Sofia alone has an area of about 30,000 envisaged for the newly constructed oil decares (nearly 12 sq. miles) and the water refinery near Burgas there is a danger of held back forms a huge lake fifteen kilo­ the oiling of birds by floating waste, metres long. A few hundred small reser­ particularly on Lake Vaya and Otmanli voirs and fish ponds have also been built. Bay. Last year we observed the first such Unfortunately, for waterfowl these enticing fouled birds - a Black-headed Gull Larus expanses of water constitute almost aquatic ridibundus, a wagtail Motacilla alba, and deserts. The inconstancy of the water level, wild ducks - and probably their number

60 THE WILDFOWL TRUST will grow. The chemical waste from some shooters, 159,000 ducks and 11,300 geese factories discharged into the marshes and were shot: and in 1945-46, with 68,000 rivers also has an unfavourable influence shooters the figures were 126,000 and on the lower animal life in the water. This 12,400 respectively. At the present time necessitates the preservation of other clean the number o f shooters is about 100,000 coastal marshes, rich in food and protective but only about 25-30,000 wild duck and vegetation, where birds can breed or rest 4-5,000 wild geese are shot annually. The during migration undisturbed. reason for this decrease lies in the reduc­ Unfortunately Bulgaria lies below the tion in the number of suitable nesting sites, southern limit of the breeding ranges of due to the draining of expanses of water in most species of waterfowl. It is definitely the lands situated to the north of this included in the breeding ranges of only country where the birds mostly breed, e.g. Anser anser, Anas platyrhynchos, Anas the Ukraine, and also in the comparatively querquedula, Aythya nyroca and Netta long shooting seasons and the lack of rufina. All the other species may have limitations on the amount of game taken nested in slightly larger numbers in the in many of the southern countries. Un­ past than they do today, but nevertheless fortunately, in the Middle and Near East it was an uncommon occurrence, and the uncontrolled and unlimited shooting of today the nesting of such birds in this waterfowl continues and hence they be­ country is quite sporadic. come in shorter and shorter supply and the The comparative warmth of recent years ‘duck crisis’ worsens. For this reason a is probably a reason for the northward severe shortening of the shooting season movement of the southern limit of the and the laying down of limits on the size breeding range of some species and it may of bags of game taken has recently been be connected with the decrease in numbers necessitated in this country. To each wild- of breeding pairs in the southern regions. fowler a limit of three wild geese and ten However the appearance of new more wild ducks is allowed. In the ‘Scheme of southerly types (particularly Central Asia­ regulations and seasons for hunting in the tic and Mediterranean or birds known to U.S.S.R.’ (1964), which has been issued be characteristic of lakes in the Steppes) for discussion, even lower limits have been has not been noticed. For example, the proposed, which makes the future pros­ occurrence of the Marbled Teal Anas pects of waterfowl more optimistic. It is angustirostris has not been established, nor proposed to allow, in one day’s shooting, has the nesting of the White-headed Duck not more than five waders and snipe and Oxyura leucocephala, and the numbers of only five wildfowl (ducks and geese) in the Gadwall have not increased. As for the European part of the U.S.S.R., and up to expansion of the range of the southerly ten small feathered game and eight water­ species Netta rufina, it began about twenty fowl in the Asiatic part and in the northern years ago and there is absolutely no great regions. The acceptance of these limits increase in its frequency in this country nor would be acclaimed by ail countries. In is it a markedly predominant species. The Bulgaria, while the shooting of indigenous disappearance of the last scattered and game is allowed only two days a week and isolated nesting sites of the Greylag Goose is not allowed except by groups of at least Anser anser and o f Tadorna ferruginea three people, migratory game (including probably indicates the unhappy prospect waterfowl) can be shot on any day of the that in the near future these birds will not week and by individuals shooting alone. be in the list of species nesting in this Formerly the shooting seasons were very country. long - from ist or 15th July (later, from ist August) to ist or 15th April. A few Wildfowling years ago new shooting seasons were estab­ As in all the countries situated in southern lished in this country - the shooting of Europe, the Bulgarian shooters are mainly wild geese begins on ist September and ‘consumers’ of wildfowl that consists not finishes on 25th March. We reckon that of local but of migrating birds which are this season is still too long and that in no ‘despatched’ to this country annually from case should the shooting season for water­ the northern lands - its ‘producers’. The fowl continue after ist March, in con­ number of Bulgarian wildfowlers has formity with the recommendations of the almost doubled in comparison with pre­ I.C.B.P. This proposal is designed to war years, but according to statistical data prevent the killing of birds that are pre­ the number of ducks killed has fallen about paring to breed, many of them having five times and of geese two to three times. paired by the middle of March and some In 1939-40 there were 36,000 shooters and having already begun to nest, e.g. Mallard, 128,000 wild ducks and 11,000 wild geese Ferruginous Duck, and especially the were shot: in 1944-45, with 55,000 Greylag Goose. This is the way in which

WILDFOWL IN BULGARIA 61 most harm is done to the few remaining and with a bait of worms and a fishing line birds still nesting in this country. We attached to a stake buried in the ground by believe that, when the shooting season for the shore. Today these unethical poaching wildfowl has been shortened in Rumania methods are no longer used. too, it will be even more possible to At the beginning of this century the guarantee an untroubled migration for the Greylag Goose was so abundant as a birds returning to the North, since this nesting bird that the fishermen from measure has already been taken in the Tataritsa in the Silistra district, Dobrudja, European republics of the U.S.S.R. and killed 40-50 Greylag Geese with sticks in almost all European countries. during the moulting period and caught The use of waterfowl is mainly for sport. about 100 young birds for food. Such Collecting their eggs is forbidden. The use devastating raids on the geese continued of their skins is now unknown and even in up to just before the last war. Thus, for the past there was only very limited and example, on 15th July, 1940, when the local use of skins, mainly of grebes Podiceps young geese had already grown almost as cristatus, etc., for the lining of clothes. The large as the parents and the adult birds collecting of down from the nests of were moulting, a gang of 70 people caught Tadorna tadorna is also unknown now, but about 150 Greylag Geese, unable to fly, in for that reason no efforts at all are made to the Koykusha Marsh between the villages prepare artificial holes in the ground in of Belene and Oresh, again by the Danube. which it can nest. In 1942, young geese with clipped wings It is absolutely forbidden by law to were kept in many gardens in the village of shoot five species: Tadorna tadorna, Sreburna. These birds had been caught on Tadorna ferruginea, Oxyura leucocephala, the neighbouring marsh, which is now a Cygnus cygnus and Cygnus olor. reserve for pelicans and other birds. Now In Bulgaria wildfowling is only a sport that abundance of geese no longer exists and has no commercial aim. It is forbidden and is already just a quickly fading memory. to sell or trade with the birds killed. Only The Greylag Goose is declining as a nesting organised shooters have the right to shoot. bird in this country. Hunting it by the Even during the Turkish oppression, in a destructive method described above is now copy preserved in the Rila Monastery of a strictly prohibited. ‘firman’ (decree) issued in the town of Shooting from a ‘gyume’ is a characteris­ Edime (Adrianople) from Sultan Bayazid tic method. This is an oriental method of Hassan II to the Grand Vizier Kara hunting, which formerly was used in Mustapha Pasha, giving him control of the Bulgaria only in the region of Thrace, but lands in the Plovdiv province, we read that has now spread to the Sofia district and among the taxes from which he was other places. The ‘gyume’ is a hut sunk exempted, besides ‘resuli badihava’ i.e. the into the earth by the marsh and covered right to breathe air, there was also ‘resuli with turf. Since it is almost below the timar’ i.e. the right to hunt birds. But with surface of the earth, it looks from above the passing of the first game law of 1880, something like an army bunker, merging all game, resident and migratory, were with the background of the marsh land­ counted as state property and only a scape. Inside it is covered with sheet iron recognised hunter had the right to hunt so as to be dry and it has a place for a small it on payment of a tax. Hunting with stove. There is room for two to five people. special nets called ‘purliga’, which was There are also portable hides, usually with carried out here and there, mainly along walls of rushes or sticks. These cannot be the Black Sea coast, principally for Quail heated. There are small openings like but also for other migrants too, was limited loopholes directed towards the marsh, or to two months (from 15th August to 15th sometimes to all sides, so that one can October) and a large tax of three gold levs shoot in various directions. This type of was imposed. Quite soon afterwards this shooting is usually accompanied by the rapacious and commercialised form of use of ‘decoys’, hybrids between domestic hunting was forbidden and forgotten. ducks and Mallard Anas platyrhynchos, Among those methods of hunting that are which have good vocal capabilities and can no longer used there are also : hunting with quack. Rubber or wooden models of wild a circular fishing net called a ‘serkme’ with ducks and the use of silhouettes or whistles weights round the edge for Coot Fulica are unknown. The decoys are usually atra and Ferruginous Duck Aythya nyroca; arranged in two diagonal lines. If they with a net called a ‘vinter’ stretched on a quack superfluously and without reason, hoop and put in the water with a live duck they may be arranged in pairs, so that each tied up inside it as a decoy; with snares male is with a female, when they keep stretched in small channels cleared among quiet. If they do not quack to lure the wild the marsh plants where the ducks swim; ducks, some are hidden in the ‘gyume’ and

62 THE WILDFOWL TRUST then the others begin to call to them. The At the end of the last century a few authors same result can be achieved if they are (Reiser, Christovich, Lorentz et al.) arranged in two separate lines, the males reported the same phenomenon in the in one and the females in the other. The villages along the Danube, in the town of wild ducks Anas platyrhynchos, Anas acuta, Svishtov and other places. This custom Aythya nyroca and, less commonly, Anas may be due to the spread of Roman influ­ penelope, Anas querquedula and Anas ence and may have been preserved through crecca respond to the quacking of the the ages since the Roman era, particularly decoys. Actually, these latter species land along the Danube in Rumania and Bul­ in front of the ‘gyume’ as much as the garia. Some historians suppose that these former ones, but they stay on one side, are were the sacred geese kept on the Capitol very wary and usually soon fly away. The hill, the cackling of which woke the decoys each have on their legs a ring which Romans and saved the old town on the is free to turn and to which is connected a approach of unfriendly forces to attack it. cord about a metre long. This cord is tied The Ruddy Shelduck is a much-loved to a ring fixed to a small stake driven into bird in the folklore of the southern Slavs. the ground. In front of each decoy is a pile In Serbian songs it is extolled as the of earth so that the bird can get out of the golden-winged ‘utva’ and in Bulgarian water and rest on the little hillock, or else songs as the golden-winged ‘shatka’. In one under water there is a stake hammered of the Bulgarian folk songs they sing about into the ground and on to it is nailed a the hunting of Krali Marco, a feudal lord board like a little table, on which the bird in western Bulgaria and Macedonia who may rest. The decoys are not fed much so became a vassal of the Turks after fighting that they are lighter and smaller in size than against them. Here is an interesting extract domestic ducks. They are most often from it : kept with clipped wings, since sometimes Krali Marco said to the king, when they fly away they do not return. ‘Gather your forces and feed your Shooting with decoys from a ‘gyume’ is falcons. a very deadly method. In the migrating Let us go to hunt game. season there are cases of over one hundred Let us hunt that wild game, birds being killed in one night. For this That wild game, the golden-winged reason the number of such erections on the duck’. marshes is limited. In the Sofia district it For this hunt they are said to have gathered is no longer permitted to build new ones, 3,000 soldiers, each with a falcon trained but the existing ones have been left to be for hunting, and Krali Marco himself had used as long as possible. a trained Imperial Eagle Aquila heliaca. Having in mind the unsportsmanlike They went to hunt game mass-productive nature of shooting wild And passed through a broad plain. ducks and geese from a ‘gyume’, which is And they reached a great lake. contradictory to the ethics of the sport, we They saw the golden-winged ‘shatkas’. reckon every limitation on this oriental All the ducks fell to the bottom, method of shooting to be a means of saving They fell to the bottom of the lake. a multitude of wildfowl on their return to They could not find a single one. their homeland. A novel from the Bulgarian renaissance In antiquity the Ruddy Shelduck at the end of the last century by Tsani Tadorna ferruginea was kept in gardens as a Ginchev mentions hunting with falcons for favourite decorative bird and as a sub­ Ruddy Shelduck, Wood Pigeons Columba stitute for a watch-dog, since it gave the palumbus and Otis tarda in the alarm on the approach of a stranger. Among meadows and flooded places overgrown discovered fragments of old Bulgarian with willows by the River Yantra. At drawings of various birds, there are some that time, during the Turkish oppression, of ducks and some showing stylised forms only important Turkish administrators of geese, which resemble this species. The and military leaders (pashas, viziers, domestication of the Ruddy Shelduck is a beys, etc.) went hunting like that with very interesting problem. It was still found trained falcons. Today that kind of here and there in this country until quite hunting is forgotten, and perhaps soon the recently. In the village of Rousocastro in Ruddy Shelduck too will be forgotten as a the Burgas district (1952), shelduck reared Bulgarian bird. In those days it really did together with domestic ducks did not try occur there by the Yantra, where Reiser to escape even though their wings were not saw it at the end of the last century. clipped. In 1950 in the village of Tyule- [Editorial note: a second part of this novo in the Dobrudja I saw a domesticated paper, discussing the status of all species of shelduck of this kind, which honked on the wildfowl known to have occurred in Bul­ approach of a stranger like a ‘live alarm’. garia, has had to be held over.]

WILDFOWL IN BULGARIA 63 Breeding of the Cape Barren Goose on the Anser and Glennie Islands, Victoria, Australia

D. F. DORWARD1 and G. M. PIZZEY2 1 Dept of Zoology, Monash University, Victoria. 2 Ceres, Red Hill, Victoria.

Sum m ary In June 1964 Cape Barren Geese were found to be breeding on the islands off Wilson’s Promon­ tory. This was the first authenticated record since 1910. This report of the 1964 findings includes introductory notes on the known history of the species and on its notable biological significance and rarity. The desirability of increased con­ servation measures is stressed and proposals for such measures (including other ecological research work relevant to good management) are outlined. Introduction waterfowl. Some workers have linked it This report was written for submission to the with the extinct New Zealand goose Fisheries & Wildlife Department of Vic­ Cnemiornis, others with the Shelducks and toria, with a view to establishing a research with the South American Kelp Geese, and and conservation programme. It is reprinted others with the true geese of the north; here, by permission, in a slightly amended some consider it deserves a tribe of its own. form. All that is certain at the moment is that the Cape Barren Goose is an unusual goose­ The Cape Barren Goose Cereopsis novae­ like bird of undoubted rarity and appa­ hollandiae is one of the rarest geese in the rently ancient origin, which possesses no world. A handsome bird, standing nearly close relatives and is found nowhere else on two feet tall, grey with black wing-tips earth - a bird worth preserving. and tail, and a striking yellow-green cere on the bill, it introduces a boid and rather The Cape Barren Goose in the Fur- wild note to the open landscape it inhabits. neaux Group, , and on the It bears a remarkable resemblance in many Victorian mainland ways to the true grey geese of the north The Cape Barren Goose breeds on a few and as such is the only one o f its type in the islands from as far as the Recherche Archi­ southern hemisphere. This ‘parallelism’ pelago in West Australia to the Furneaux or convergence is of considerable zoological Group, but the latter area is its head­ interest. quarters. Aerial surveys conducted since It received its vernacular name after 1957 by the Tasmanian and Bird being used as a source of much-needed Protection Board indicate that the popula­ food by survivors of the ship “Sydney tion in the Furneaux Group has fluctuated, Cove”, wrecked on Preservation Island counts varying from 943 in i960 to 2,600 south of Cape Barren Island in Bass Strait in 1964. early in 1797. Matthew Flinders, who The Cape Barren Goose has a long travelled there from Port Jackson in the winter breeding season. It commences rescue schooner ‘Francis’, commented laying as early as April and continues in ‘. .. I found this bird in considerable some cases until the end of October. About numbers on the smaller islands, but September each year some flocks make an principally upon Preservation Island; its annual summer migration to the plains of usual weight was from 7 to 10 pounds and Western Victoria, but the migratory habits it formed our best repasts, but had become of the species are still to be investigated, a shy . . .’. About the same time, in the project only now getting under way. So summer of 1797-98, George Bass recorded far as is known, at present there are only taking geese on unidentified islands off about four places where geese may be seen Wilson’s Promontory during his whaleboat with any certainty during this summering voyage to Westernport. Together with period. In each case these are jealously- mutton-birds and seals they formed an guarded grazing properties. In one place a important food standby. flock of 100 birds appears most years but Early as these records may seem, they records of 50 years ago indicate that such appear late in the Cape Barren Goose time- flocks were once found over a much larger scale. Recognisable waterfowi occur in the area of the Western District. There is little fossil record as early as the Cretaceous, 60 doubt that overall numbers have shown a million years ago. Studies on its bone- considerable decline. Since the majority of structure, muscle-formation and behaviour Cape Barren Geese seen during this sum­ are currently going on in an attempt to mer migration probably originate in the establish its relationships with the other Furneaux Group, hitherto it seemed that

64 THE WILDFOWL TRUST their continued presence in Victoria and Glennie Groups in a fishing boat depended on the success of the conserva­ chartered from Port Franklin. High winds tion efforts of another State. It is now four and rough seas made possible only an years since the last shooting season of four inspection by sea of Wattle, Kanowna and weeks was permitted in the Furneaux Anser Islands in the Anser Group and of Group. On that occasion 184 licences were the eastern sides of Greater Glennie, issued and 252 birds taken, which may have Dannevig, Citadel and McHugh Islands represented something like 20% of the in the Glennie Group. Geese were seen on total Furneaux Group population, as the all these islands. Finally, a landing was aerial count of the previous year had shown made on , numerous there to be about 1,200 geese in the area. geese were seen, and four nests with eggs Since then the bird has been declared a discovered. partly-protected species, and it has been The greatest numbers of Cape Barren claimed that numbers have shown an Geese seen at one inspection during the increase, although there is little doubt that investigation, which took place between some illegal shooting, destruction of eggs, June 13 and 17, were as follows. and capture of goslings continues. We have observed geese in these islands, and appre­ Anser Group ciate the problems faced there by the Wattle Island - 4 pairs, possible duplica­ Tasmanian conservation authorities. The tion of I pair; Anser Island - 6 pairs on goose islands are scattered, sometimes ground, flock of 20 flying ; considerable distances from the nearest - 3 pairs. port, and hard to police. They are fre­ quented by fishermen (not only local ones) Glennie Group and mutton-birders ; some are privately Great Glennie Island - 23 geese flew as the owned, and farmers grazing stock are in boat arrived. 9 pairs seen elsewhere; some cases antagonistic to the presence of - 3 pairs; - grazing geese. Of all these islands (about 3 birds; McHugh Island - 1 pair. 20), one, Goose Island (about 250 acres T he occurrence of geese in pairs intruded and one of the most remote) has been itself immediately. Generally these were declared a sanctuary; one other smaller seen on more or less pure areas of poa one, Little Woody, has been reserved for tussock of anything from one to five or more wildlife purposes; and in the cases of those acres in extent, ranging from 50 feet above islands held on Crown Land leases, it is sea-level, where vegetation succeeds the intended that restrictive clauses beneficial steep granite shoreline, to the crests of the to the geese will be inserted when the leases islands which vary in height between 150 become due for renewal. and 500 feet. With practice it became possible to predict areas where geese would The Cape Barren Goose on Victorian appear as the boat approached. Invariably islands the birds were already alarmed by the time In view of the situation in the Furneaux they were distinguished, and just as Group, the status of the species on islands invariably flew before the boat approached off the Victorian coast, many of them within gunshot. In the light of the tameness already declared sanctuaries and none of Cape Barren Geese observed on the having grazing interests or being privately adjacent mainland at the conclusion of the owned, is of some interest. investigation (see below) this wildness A perusal of old records, conversations would seem to indicate that on the islands with fishermen, and a brief visit by D.F.D. at least the birds associate the approach of during the non-breeding season, indicated a boat with gunfire, or at least danger in that the Glennie and Anser Groups of one form or another. No flying birds were islands off Wilson’s Promontory might be seen to cross between the islands. When breeding grounds for geese. As already disturbed they either moved directly to mentioned, Bass had taken geese on settle on another part of the same island, islands off the Promontory in 1797-98. or flew about for a short time before doing More recently, in 1910, a party of Mel­ so. bourne naturalists, which included Sir Since the prime purpose of the venture James Barrett, had landed on Great was to establish beyond doubt that the Glennie Island and reported geese breed­ Cape Barren Goose still breeds on the ing. Contemporary records in the files of islands, the time spent ashore on Great the Fisheries and Wildlife Department Glennie Island was directed entirely to a indicated the presence of geese on several search for nests. To this end all 10 members of the islands, although apparently no formed a beat along the eastern slope of the breeding records had been made. Accord­ island, moving northward from the anchor­ ingly, in June a party of ten visited the Anser age. However, it soon proved that stalking

CAPE BARREN GOOSE 65 was more effective than beating, since the development of the area proceeds. It would birds rose at extreme range and 3 of the be desirable to restrict or prevent landing 5 nests discovered were located by Dor- on the islands to minimise disturbance of ward who had observed birds in pairs on breeding geese. two of the territories during a visit to Great The anchorage at Great Glennie pro­ Glennie in April 1964. Two nests, several vides the only shelter on the west coast of hundred years apart, were sited in an area the Promontory. Professional fishermen of tussock 50 ft. above sea-level directly have been using this anchorage and landing above the steep granite slope rising from on Great Glennie, and probably shooting the sea. One of these nests was empty but geese, since these waters began to be fresh, the other contained five eggs. The worked. One of the authors has been told other three nests were on the exposed by fishermen in a nearby coastal town of ridge of the island, some 200 ft. above sea- parties taking up to 40 geese in a day, and level. One nest had five eggs (three stained, of goslings being brought home for pets. two clean) and a down lining. The second The comparatively small size of these had two little-stained eggs. The third, only islands makes shooting easier; geese do some twenty feet from the second, was not normally leave the islands on being empty and weathered. It lacked down and disturbed, but fly about and offer many was probably at least a season old. All five chances. nests were built in slight depressions hard Hence there is need for active measures against tussocks on the lee side, the wind- to protect the geese of these islands from curved grass tending to bend over them. shooting. Probably the cheapest method The nest territories appeared to be approx­ would be a non-regular aerial patrol. Such imately 300-500 yards in diameter. a patrol would seek to recognize any boats It seems reasonable to conclude that in the anchorage. The propaganda value of between the months of April and Decem­ such a patrol would probably be greater ber the Anser and Glennie Groups form than the actual policing function. an important Cape Barren Goose breeding At the same time an aerial count of the ground. Apart from flocks at least 26 pairs geese along lines pioneered in Tasmania of birds were seen. The amount of available could be used to assess the annual fluctua­ territory would seem to suggest that at the tion in numbers, an essential part of any time of our visit there may have been two wildlife management programme. Includ­ to four times that number of pairs actually ing Norman and Shellback Islands, the present and about to breed. In other words, Groups concerned are strung over a dist­ up to five per cent of the world’s Cape ance of some twenty miles, and could easily Barren Goose population may rely on be covered in a morning’s flying. The air these Victorian islands for breeding pur­ distance from Moorabbin Airport, Mel­ poses. This is a possibility which has bourne is 100 miles. apparently not been appreciated up to the Another important step which could be present. taken at present would be irregular patrol­ ling by a sea-going boat. Inspectors of the Conservation Fisheries and Wildlife Department are Any conservation campaign to ensure the already responsible for maintaining watch security of this breeding population of on the area and the activities of fishermen. geese must rest on more than the declara­ If a Fisheries and Wildlife Department tion of sanctuaries, since both groups of vessel were available for all the Depart­ islands have long been designated as such. ment’s coastal commitments, policing of The four main islands in the Glennie the islands could be made an additional Group - Great Glennie, Dannevig, Cita­ one. del and McHugh - were declared a sanc­ tuary in 1910; the Anser Group, and the Research two northernmost islands on the west coast The Cape Barren Goose is not only a rare of the Promontory (Norman and Shellback animal, it is also one of considerable zoo­ Islands), and in addition Rabbit, Granite, logical interest. At present, ecological Doughboy and Benison Islands on the east research is being done on its breeding coast, all became part of the Wilson’s biology by workers in Tasmania, and one Promontory National Park in 1916. It is of the authors is conducting a research already becoming the practice of the hardier programme on its behaviour, history, holiday fishermen to take light boats out classification, and evolutionary relation­ through the surf from the popular Tidal ships at Monash University. Hitherto all River settlement, from which Great Glen­ field work has necessarily involved travel­ nie Island is a bare six miles - about 20 ling to Tasmania. In light of the recent minutes run in a fast dinghy. Access to the discoveries, it is hoped that the emphasis islands will presumably become easier as of the Monash programme will shift to the

66 THE WILDFOWL TRUST Victorian coast. The Department of National Parks Authority and to the Zoology at Monash. University already is Director of Lighthouses, Commonwealth beginning to work in co-operation in a Department of Shipping and Transport, number of ways with the Fisheries and for permission to make plans for such Wildlife Department, and it is envisaged research work in areas under their jurisdic­ that further co-operation will arise in the tion. case of the Cape Barren Goose. Thus, for Research is the basis of any conservation example, research workers making obser­ programme. The research discussed above, vations regularly on the islands could assist together with the protection measures, with poilcing, while their transport diffi­ would constitute such a programme. Since culties might be eased by the Department the Cape Barren Goose, like most water­ vessel. Again, while research workers catch fowl, is a potential game bird, a conserva­ geese for banding and other purposes, X-ray tion programme for it is the same as a game examination of the birds (for determination management programme. Eventually, any of shooting pressure, as already in progress successful game or wildlife management for ducks) could be carried out. Also, at the programme comes to include some con­ Department’s wildfowl study area at Lara trolled cropping. This would no doubt be a breeding programme for geese is planned ; appreciated by sporting interests in the studies complementary to those in the State. In addition, a successful programme islands could be made, and birds reared for would earn world-wide respect in the field release in the islands. of conservation research, a field in which Other ecological studies for the islands present successes are few and when they are in the planning stage: a new Monash occur highly acclaimed and remarkably University Research Scholar will, it is popular (as, for example, the Koala in hoped, undertake work on the ecological Victoria and the return of the Osprey to inter-relations of burrowing sea-birds the Scottish Highlands). The World Wild­ (petrels, ) and rabbits. Rabbit and life Fund and the International Union for Citadel Islands are particularly suitable for the Conservation of Nature would un­ this purpose. A study of the regeneration doubtedly lend approval and support to and rehabilitation of following this project, although their commitments removal of rabbits (a project already dis­ elsewhere are already too great to make cussed with the Vermin and Noxious financial support probable. The State of Weeds Destruction Board) is proposed; Victoria has the reputation of being a the relevance of this to geese is that restora­ leader in Australian conservation matters. tion of the habitat would almost certainly It seems highly desirable that the chance result in re-occupation of these islands by to preserve one of the country’s rarest birds geese. Approach has been made to the should be seized while it yet remains.

The ecology and numbers of aquatic birds on the Kafue Flats, Zambia R. J. DOW SETT and A. de VOS Department of Game and Fisheries, Chilanga, Zambia, (R. J. Dowsett) and Kafue Basin Survey, F.A.O. (A. de Vos)

Introduction between a few inches and 10 feet. The rise The Kafue Flats in southern Zambia are and fall of the flood water is a gradual located at about i5°3o'S and between 27 process. and 28°E. They are flooded annually by The Kafue Flats area, with its striking the Kafue River, and extend for some 140 concentrations of Lechwe antelope and miles along the river with a width of birds (including wildfowl, shorebirds, between 10 and 30 miles. The total area wading and some fish-eating birds), has of the Flats is some 2,500 square miles. long been considered one of the greatest The area is at an elevation of about 3,100 spectacles in Africa. Many distinguished ft; it has an average rainfall of 32 inches ornithologists have expressed the opinion per annum and a mean annual temperature that the variety and numbers of aquatic of 70-75°F. The flood water rises, after birds on the Flats compare favourably with the rains have begun, in November and the best wetland areas in the world. The December and the flood peak occurs preservation of this area for all time has between April and June. At times of peak long been advocated. Two of the most flood the level of water on the Flats varies important sectors of the Flats remain

CAPE BARREN GOOSE 67 under private ownership. Although con­ means of numerous observations on the siderable protection has been afforded by ground, a number of sample transects and the owners of Lochinvar Ranch (on the an aerial flight. The numbers obtained are south side of the Kafue River) and of Blue necessarily approximate due to limited Lagoon Ranch (on the north side) - pri­ time available, but these figures provide a marily to conserve Lechwe - anything basis for future research. short of the creation of a National Park Numerous observations were made dur­ must be considered unsatisfactory if this ing the period August to November on unique spectacle is to survive. Lochinvar and Blue Lagoon Ranches, Little is known about the ecology and mainly by the senior author. A good deal movements of aquatic birds in Central of ground was covered. Sixty-three days Africa. The Kafue Flats provide perfect were spent in the field in 1964 and about conditions for the study of wildfowl one quarter of this time was spent on breeding, habitat and movements. Scien­ ornithological work (the remainder being tific names of all species mentioned in the devoted to Lechwe studies). The approxi­ text will be found in Appendix 2. The mate area in which aquatic birds were nomenclature used is that of C. W. Benson censused was 50 square miles on Lochinvar, and C. M. N. White Check List of the Birds and 8 square miles on Blue Lagoon. Within of Northern Rhodesia, Lusaka, 1957. these areas most aquatic birds were con­ centrated in a few places where the habitat Numbers was suitable. Each of the concentrations Between August and November 1964 the was counted at least once. The figures in authors made preliminary attempts to Table I, which are totals of birds counted obtain an estimate of the numbers of in the concentrations, may be taken as the aquatic birds (i.e. cormorants, pelicans, totals for the whole census area of 58 herons, egrets, , ibises, ducks and square miles. geese) on the Flats. This was done by

Table I. Numbers of aquatic birds found in censuses of 58 sq. miles within the Kafue Flats, August-November, 1964

counts av. no. per range mean sq. mile

Reed Cormorant 301-348 325 5 6 Darter 74-106 90 1-6 White Pelican 1719-1999 1859 321 Grey Heron 32-46 39 0-7 Goliath Heron 32-37 35 06 Purple Heron 32-38 35 0-6 Great White Heron 124-141 133 2'3 Little Egret 42-55 49 0-8 Yellow-billed Egret 102-260 181 3 1 73-129 101 1-7 Squacco Heron 129-164 147 2'5 Rufous-bellied Heron 32-39 36 06 Openbill 1019-1247 1133 195 Saddlebill 26-28 27 0 5 Marabou 41-57 49 0-8 Wood Ibis 104-116 n o 1-9 Sacred Ibis 107-129 118 2-0 Glossy Ibis I 19-229 174 3-0 African Spoonbill 25-33 29 0-5 Hottentot Teal 52-72 62 I I Red-billed Teal 3114-5660 4387 756 White-faced Tree Duck 2227-3031 2630 45 3 Fulvous Tree Duck 1227-6327 3777 651 Knob-billed Goose 539-668 604 10-4 Spur-winged Goose 3770-4362 4066 70-1 Fish Eagle 30-36 33 0-6 African Jacana 261-597 429 7'4 Crowned 106-196 151 2-6 260-264 262 4-5 Blacksmith Plover 262-574 423 7'3 Long-toed Plover 125-143 134 2'3 Stilt 97-130 114 20 Grey-headed Gull 437-1062 750 12-9

68 THE WILDFOWL TRUST Several of the species listed are known to density per square mile of 75.6 given for wander quite extensively on the Flats, but the most numerous local duck, the Red­ it has been assumed that movements on and billed Teal, would give a total o f 189,000 off the two ranches are likely to be equal. individuals in the 2,500 square miles of the It is necessary to point out that some Flats. species appeared more prone to wandering A number of sample transects were than others, and this explains the fluctua­ taken. Water levels dropped so rapidly tions in numbers of such species as Red­ during this period that in most areas billed Teal, Fulvous Tree Duck and Grey­ aquatic birds frequently had to move from headed Gull. Some species might have one suitable locality to another. These escaped notice on occasions, especially transects therefore scarcely reflect a true skulking Squacco Heron, African Jacana pattern of movements. Nevertheless, it and nesting Blacksmith Plover. Counts of seems worthwhile discussing a few general the more conspicuous species, such as aspects that arise from the data. Between Goliath Heron, Saddlebill, Spur-winged August and November 1964 there were far Goose, Fish Eagle and Wattled Crane more aquatic birds per acre of suitable show reasonable agreement between the habitat on Lochinvar than on Blue Lagoon. several counts made, and hence their range This is especially true for ducks, and less as shown in the table is limited. Fluctua­ so for egrets, herons and Spur-winged tions in some other species cannot be Geese. However, parts of Blue Lagoon did explained. No worth-while counts could be hold especially good numbers of egrets and made of the smaller species of shorebirds. herons. These differences are apparently In the absence of more intensive obser­ the result of differences in the habitat vations it is not possible to make any esti­ requirements of various species, which will mate of numbers on the Kafue Flats as a be discussed more fully. whole. However, the areas censused Five counts along transect I at Lochinvar probably carried as high a density as between 19th August and 3rd September anywhere on the Flats; by taking an showed that although ducks and geese may average density over both suitable (con­ move around a great deal, the majority of centration areas) and unsuitable areas (dry egrets and herons may remain in one area grassland surrounding the watered zones) for as long as it suits their needs. However, as has been done in the foregoing table, Spur-winged Geese and White Pelicans figures are obtained that might be taken as fluctuated greatly in the two counts over representative of the entire Flats area until transect I at Blue Lagoon. more detailed surveys are possible. To Transect II at Lochinvar on 4th August give some idea of the potential of the area was part of a count made by the junior as a major wildfowl centre, the average author of some species along 165 miles of

Table II. Numbers of aquatic birds seen along 165 miles of the Kafue River, 4th and 5th August, 1964

total seen ave. per mile of river

Reed Cormorant 4 14 4 251 Darter 282 1-7 White Pelican 50 03 Grey Heron 8 005 Goliath Heron 30 0-2 Purple Heron 3 0 02 Great White Heron 24 o-i Little Egret 280 1-7 Yellow-billed Egret 84 0 5 Cattle Egret 4 0-02 Squacco Heron 91 0-6 Rufous-bellied Heron 2 001 Openbill 4354 26 4 Marabou 60 0-4 Wood Ibis 10 006 Sacred Ibis 275 1-7 Glossy Ibis 6 0-04 Fish Eagle 72 04 Spur-winged Goose 79 0-5 Crowned Crane 3 0-02 Wattled Crane 3 0 02 Grey-headed Gull 1553 9-4

AQUATIC BIRDS IN ZAMBIA 69 the Kafue River upstream from the Kafue of aquatic birds. Much of the semi­ Bridge. The 165 miles were censused waterlogged anthill zone, and the pans in on 4th and 5th August in a motor-powered the woodland area, provide suitable condi­ boat, and an attempt was made to record tions for several species to nest in con­ all birds present on the river. The counts siderable numbers. Unfortunately, the of the main species are shown in Table II. Flats are little visited during the rains, and From this census it was evident that the knowledge of the breeding birds of the 13 mile stretch of the Kafue River along area is sparse. Towards the end of the the Lochinvar boundary, and some 30 rains pelicans, some herons and egrets miles to east and west of it, contained some probably breed out on the Flats, but again 80% of the aquatic birds recorded on the few data have been collected. As the water whole trip. Within this area of concentra­ level drops steadily, new food supplies are tion there was a fairly even distribution of continually uncovered for the considerable aquatic birds: for example, the overall numbers of various species that feed in average number of Reed Cormorants per shallow water and along the water’s edge. mile was 25, with 2 Darters and 9 Grey­ In a really dry year permanent streams and headed Gulls, and these figures differ little lagoons will provide suitable feeding until from the number per mile along the boun­ the flood waters begin to rise again. dary of Lochinvar (30,3 and 2 respectively). The following notes indicate habitat This census also confirmed that several preferences of certain species during the fish-eating species such as Reed Cormo­ second half of the dry season, as noted rant and Grey-headed Gull occur in very during August to November 1964. large numbers on the river although they may be scarce on the Flats. Other species, Reed Cormorant and Darter such as Skimmers (of which a party o f 10 Present in rivers, lagoons and permanent was observed on the river, and which does streams, numbers fluctuating as numbers occur at both Lochinvar and Blue Lagoon of fish vary locally. Reed Cormorant more in flocks o f up to 100), also occur in suit­ likely than Darter to be found on small, able habitat on the river, but not on the reedy streams and inundated areas, and on flood plain itself. permanent water the former seems always When water levels on the Kafue Flats more numerous. are dropping steadily, transects have a White and Pink-backed Pelicans dubious value. However, transects along the edge of the flood line either at peak Usually in small parties, but the White flood or in a year when the water level Pelican may occur in concentrations of drops slowly, might give useful results. several hundreds where fish (especially On 19th September one of us (A. de Schilbe mystus and Clarias mossambicus) are Vos) took part in a flight over a section of temporarily numerous. The Pink-backed the Kafue Flats. Estimates of total numbers apparently does not occur in large numbers. of some species present were as follows: Both species wander a great deal, depend­ W hite Pelican 350 (would include a few ing on concentrations of fish, on rivers, Pink-backed); Great White Heron 1,500 lagoons and streams, or even shallow flood (might include a few Yellow-billed and plain. A freshly dead White Pelican little Egrets); Openbill 7,000; Wood Ibis contained three Clarias mossambicus, total­ 500; African Spoonbill 200; Red-billed ling 10 lbs., on 6th October (A. T. Fuller, Teal 5,000; White-faced and Fulvous Tree pers, comm.) Duck 15,000; Spur-winged Goose 3,500; Herons, egrets, storks, etc. Crowned Crane 50; Grey-headed Gull Shallow flood plains: Great White Heron, 500. Little Egret, Yellow-billed Egret, Rufous- The flight was carried out at a height of bellied Heron, Wood Ibis, Sacred Ibis, about 400 feet, in good visibility and with Glossy Ibis. an airspeed of 185 miles per hour. Further flights, at a reduced height and with slower Muddy edge of inundation: Grey Heron, airspeed, would probably produce rea­ Little Egret, Black Heron, Cattle Egret, sonably accurate data about the numbers Hammerkop, Openbill, Saddlebill, Mara­ of most species present. bou, Glossy Ibis, African Spoonbill. Vicinity of permanent water: Grey Heron, Habitat preferences Goliath Heron, Purple Heron, Squacco Without the seasonal rise and fall of water Heron, Saddlebill, Marabou. level on the Flats, much of the area would Reeds: Purple Heron, Squacco Heron. be far less favoured by aquatic birds than it is. During the rains the shallow inunda­ Drying mud flats and damp plains: Cattle tion of much of the Flats provides exten­ Egret, Openbill, Marabou, Sacred Ibis, sive and suitable feeding for most species Black-headed Heron.

70 THE WILDFOWL TRUST Ducks and geese Flats is important, and until some attempt African Pochard: A diving duck requiring is made to solve the many problems that fairly deep channels or lagoons, although arise, proper management of aquatic birds A. J. Tree (in litt.) considers that in the in the area cannot be hoped for. North Kafue it may prefer inundated areas So little is known of aquatic bird move­ to perennial waters. Generally uncommon ments in Zambia that this subject can be throughout Kafue basin. touched on only briefly, and a few oustand- ing examples given. Reed Cormorant, Yellow-billed Duck: A dabbling duck Darters, pelicans and Grey-headed Gulls usually in shallow pools or edge of inun­ move as the areas in which fish are con­ dated areas. Apparently never in any centrated change. The , Clarias numbers on the Flats. mossambicus, can often be seen moving in Hottentot Teal. A dabbler, feeding in very large schools and the wanderings of fish shallow water. Feeds a good deal by night, predators with them may be considerable. often resting during the day in deeper Openbills occasionally move down the water. Kafue River in flocks of several thousands, Red-billed Teal: A dabbler feeding in between July and October; such move­ shallow or fairly shallow water along ments have been observed in the North muddy edge of streams, in inundations or Kafue Basin (Tree, pers, comm.) and on small pools. the Kafue Flats. Cattle Egrets, Sacred Ibis and an African Spoonbill all ringed in their White-faced Tree Duck: Feeds mainly at breeding areas in South Africa have been night in shallow water or on bare mud. By recovered in Zambia in their non-breeding day frequently resting in considerable season. numbers along water’s edge. Fulvous Tree Duck: Generally less numer­ Associations with Lechwe ous than the last species. Habitat prefer­ The main concentrations of aquatic birds ences appear identical, although the during the period August to November Fulvous Tree Duck may prefer inundated 1964 were often in areas frequented by grassland to bare mud. Lechwe, and this was especially noticeable Pygmy Goose. Sometimes inundations, during an aerial flight over part of the Flats usually permanent lagoons, as long as on 19th September. There does not appear plenty of floating water lilies and grasses to be any other reason for this than that available. Lechwe and aquatic birds had similar habitat preferences during the period of Knob-billed Goose: Usually inundated observation. flood plain or lagoons with water lilies and Lechwe may have an indirect effect on floating grasses. aquatic bird numbers on the Kafue Flats Spur-winged Goose: Swampy ground, in so far as fish numbers are dependent upon inundated grassland or dry ground with the fertility of the water, which may be fresh flush of grass growing. increased by Lechwe excrement. However, information obtained by the Fisheries The above notes show the usual habitat Section of the Department of Game and preferences of the major species of aquatic Fisheries, based on analyses carried out by birds. It is not proposed to discuss pre­ the Public Analyst, suggests there is no ferences of resident and migratory shore­ significant difference in chemical constitu­ birds here, nor of the less common aquatic tion of water from Lochinvar and from birds, but it should be remembered that other areas. Reed Cormorants, Darters, the Flats are an important nesting and pelicans and Grey-headed Gulls do seem feeding area for many African shorebirds, to be dependent upon the very large and that at times many hundreds of numbers of fish that occur in the vicinity of Palearctic migrants pass through the area. Lochinvar. Both areas, the Kafue River The main prerequisite for all these species especially, held very large numbers of fish and for most of the aquatic birds discussed at this time. above is shallow water with ample feeding, The only direct associations of birds and deeper water to which to retire for rest with Lechwe appear to be those species or escape from predators. The seasonal rise that feed on insects disturbed by Lechwe, and fall of the water level on the Kafue namely Cattle Egrets and Cape and Flats produces habitat ideally suited to an Yellow Wagtails. Cattle Egrets are seen less enormous number of water birds. often with Lechwe on the Flats than with cattle: they probably avoid getting their Movements feet wet if possible. Yellow Wagtails The whole question of the migrations or (Palearctic migrants) feed around the feet wanderings of aquatic birds on the Kafue of Lechwe, but Cape Wagtails have been

AQUATIC BIRDS IN ZAMBIA 71 seen to climb all over a standing or bedding Aug. (1 mixed, eggs). All in colonies with Lechwe, picking flies from inside its ears Darter, which it outnumbers; sometimes and off its body, the Lechwe readily sub­ various herons and egrets also present. mitting to such behaviour. If the ‘Lechwe Darter: Details as for previous species, fly’ (Musca sp.) is dependent upon the than which less numerous. Lechwe for its existence, then it is worth White Pelican: Two records of small remarking here that a great many swifts, colonies (one with Crested Crane) in hirundines and pratincoles and other birds March and April. appear to eat a tremendous amount of these Grey Heron: March, 12 nests in a mixed flies at certain times of the year on the colony of cormorants, herons and Open- Flats. bills. The need for management Purple Heron: August, at least 100 nests The aquatic birds of the Flats are depen­ in a mixed cormorant and heron colony. dent upon the seasonal rise and fall of the Except for one nestling all contained eggs. water level to provide suitable feeding Great White Heron: Mixed colonies, grounds. Any decrease in the amount of August (x) and March (2). water at present entering the Flats, such as Squacco Heron: 50 nests in a mixed might be caused by a dam on the Kafue cormorant/heron colony, August, all with above the Flats, would seriously affect eggs. numbers of aquatic birds. The amount of Night Heron: Details as for Squacco suitable habitat for feeding would be Heron. reduced drastically, and if the only water available were to be restricted to rivers Openbill: A large colony of this species, and lagoons, a considerable decline in October. 24 nests in a mixed colony, with wildfowl numbers would follow. Areas on cormorants and herons, March. the Flats suitable for nesting would be lost Saddlebill: Four records of nests or fledged to many aquatic birds and shorebirds. birds in April (1), May (2) and August (1). If properly managed the aquatic birds of Egg laying apparently in April. A solitary the Kafue Flats can give pleasure to many nester. tourists and sportsmen. If neglected, this White-faced Tree Duck: At Lochinvar magnificent spectacle will soon be just a lays in February and March in woodland memory. Already there are signs that all often J mile from water. A female shot in may not be well with the reproduction of February contained an almost fully de­ aquatic birds on the Flats. Few species can veloped egg. be age-classified in the field. Nevertheless, Fulvous Tree Duck: One record of a pair sample counts on Lochinvar and Blue with 4 ducklings on October ist. Lagoon suggest that White Pelican, Wood Pygmy Goose: One record of ducklings Ibis and Saddlebill numbers include no more than 5% immature birds. More less than a week old in late October. research along these lines is urgently Knob-billed Goose : At Lochinvar hatches required, and a research station should be regularly February and March at tempor­ established on Lochinvar. ary pools in woodland. Spur-winged Goose: 12 records of eggs Acknowle dgements or young in February (4), March (1), April We should like to thank the following (1) and June (6) - in this latter month most for their assistance: Mr. A. T. Fuller and records refer to goslings. Also a record of a Lt. Col. and Mrs. R. A. Critchley for number of broods in late December. At facilities extended at Lochinvar and Blue Lochinvar, eggs laid regularly January to Lagoon Ranches, respectively; and Mr. March, often on anthills. A. J. Tree for providing information on Crowned Crane: A record of many nests wildfowl in the North Kafue Basin. near a White Pelican colony in mid-April. Appendix 1 Apparently nests in some numbers in the flooded anthill zone at Lochinvar in the Breeding records of aquatic birds second half of the rains (A. T. Fuller, from the Kafue Flats pers. comm.). (Original records of all data used are on file with Mr. C. W. Benson, Rhodes- Appendix 2 Livingstone Museum, Livingstone, Zam­ List of scientific names of species men­ bia.) tioned in text Reed Cormorant: March (2 records, Mammals mixed colonies, with eggs), April (6, mixed, Lechwe (Kafue Flats form) Kobus leche eggs and young), May (1 mixed, eggs) and kafuensis

72 THE WILDFOWL TRUST Birds Reed Cormorant Phalacrocorax africanus Fulvous Tree Duck Dendrocygna bicolor Darter Anhinga anhinga Pygmy Goose Nettapus auritus White Pelican Pelecanus onocrotaus Knob-billed Goose Sarkidiornis melanotos Pink-backed Pelican Pelecanus rufescens Egyptian Goose Alopochen aegyptiacus Grey Heron Ardea cinerea Spur-winged Goose Plectropterus gambensis Black-headed Heron Ardea melanocephala Red-knobbed Coot Fulica cristata Goliath Heron Ardea goliath African Jacana Actophilornis africanus Purple Heron Ardea purpurea Lesser Jacana Microparra capensis Great White Heron Egretta alba Crowned Crane pavonina Little Egret Egretta garzetta Wattled Crane carunculatus Yellow-billed Egret Egretta intermedia Kittlitz’s Sandplover Charadrius pecuarius Black Heron Egretta ardesiaca Three-banded Plover Charadrius tricollaris Cattle Egret Ardeola ibis Caspian Plover Charadrius asiaticus Squacco Heron Ardeola ralloides Long-toed Plover Hemiparra crassirostris Rufous-bellied Heron Butorides rufiventris Blacksmith Plover Hoplopterus armatus Hammerkop Scopus umbretta Ethiopian Snipe Gallinago nigripennis Openbill Anastomus lamelligerus Curlew-Sandpiper Calidris ferruginea Saddlebill Ephippiorhynchus senegalensis Little Stint Calidris mmuta Marabou Leptoptilos crumeniferus Ruff Philomachus pugnax Wood Ibis Ibis ibis Common Sandpiper Tringa hypoleucos Sacred Ibis Threskiornis aethiopicus Marsh Sandpiper Tringa stagnatilis Glossy Ibis Plegadis falcinellus Greenshank Tringa nebularia African Spoonbill Platalea alba Wood Sandpiper Tringa glareola Fish Eagle Haliaeetus vocifer Curlew Numenius arquata White-backed Duck Tkalassornis leuconotus Whimbrel Numenius phaeopus African Pochard Aythya erythrophthalma Stilt Himantopus himantopus Yellow-billed Duck Anas undulata Pratincole Glareola pratíncola Black Duck Anas sparsa Grey-headed Gull Larus cirrocephalus Cape Wigeon Anas capensis White-winged Black Chlidonias leucoptera Hottentot Teal Anas punctata Whiskered Tern Chlidonias hybrida Red-billed Teal Anas erythrorhynchos Cape Wagtail Motacilla capensis White-faced Tree Duck Dendrocygna viduata Yellow Wagtail Motacilla flava

Observations on some aberrant Australian Anatidae PAUL A. JOHNSGARD1 Department of Zoology and Physiology University of Nebraska Lincoln, Nebraska Summary Field observations on the Pink-eared Duck, Freckled Duck, and Blue-billed Duck generally confirm earlier conclusions regarding the affinities of these birds. The Pink-eared Duck’s vocalisations and displays suggest that it is an aberrant dabbling duck having surprising behavioral similarities to the typical shovelers that are probably the result of evolutionary con­ vergence. The Freckled Duck exhibits a curious mixture of swan or goose-like anatomical and behavioral features that must be weighed against a duck-like bodily form. These conflicting and unusual features of the species suggest that it should be given tribal status in the subfamily , or at the very least should be removed from the dabbling duck tribe, with which it shares almost no features. Observations on flight, sound production and sexual behaviour of the Musk Duck, and on molts and vocalisations in the Blue-billed Duck are included. i Studies (No. 366) from the Department of Zoology and Physiology of the University of Nebraska.

Introduction tially limited to Australia and are rnono- It is difficult to describe the waterfowl of typic. The taxonomic positions of several Australia without resorting to such terms of these have been disputed at various as ‘unique’, ‘remarkable’, or ‘incredible’, times. Thus, the Magpie Goose Anseranas Although only 19 species are regularly semipalmata is generally regarded as repre­ found on that large continent, these include senting a distinct tribe and subfamily, a representatives of all the sub-families and conclusion supported by abundant anato- tribes accepted by Delacour (1954-1964) mical (Boetticher, 1943, Miller, 1919, except the sea ducks. Delacour, 1954, Woolfenden, 1961), bio- Of the 13 genera represented, six chemical (Sibley, i960, Tyler, 1964) and (Anseranas, Cereopsis, Chenonetta, Biziura, behavioral (Johnsgard, 1961) evidence. Malacorhynchus and Stictonetta) are essen- However, Davies and Frith (1964) have

AQUATIC BIRDS IN ZAMBIA 73 recently advanced the theory that the swimming, exposing a buffy undertail Magpie Goose is possibly a typical goose colouration that is quite conspicuous. Not that has been modified through the action all the birds exhibited such markedly buffy of convergent evolution into its present coloring, and I suspect that this variation form, a view which presently appears to must have sexual or seasonal significance, have little supporting evidence. The Cape but I could not resolve this point. Aside Barren Goose Cereopsis novae-hollandiae from this, the strong vertical barring on the likewise exhibits a combination of sheld- flanks sets the Pink-ear apart from all other goose-like features (Delacour, 1954) con­ Australian waterfowl, and its colloquial trasted with anatomical and behavioral name, ‘Zebra Duck’, is an apt one. similarities to the true geese (Woolfenden, Throughout my stay the Pink-ear re­ 1961, Johnsgard, 1961). The Maned Goose mained by far the shyest of the ducks I Chenonetta jubata, once included with the observed. Repeatedly, large flocks would sheldgeese, s now generally agreed to take to the air at the slightest disturbance, represent a southern hemisphere perching accompanied by a chorus of whistled alarm duck. The Musk Duck Biziura lobata, notes. The passing over of even such although large and grotesquely wattled, innocuous birds as the Australian Pelican clearly exhibits affinities with the typical Pelecanus conspicillatus would cause a stiff-tailed ducks (Oxyura). The shoveler- general panic among the Pink-ears, and the like Pink-eared Duck Malacorhynchus first sight of any raptors was certain to membranaceus has, in the absence of produce the same effect. However, I was contradictory evidence, been usually re­ told by several persons that at times Pink- garded as an aberrant dabbling duck, and ears are amazingly tame, and will remain the same applies to the little-studied oblivious to human beings only 20 or 30 Freckled Duck Stictonetta naevosa. yards away. Because neither of these two latter Pink-ears fly extremely well, and are species has been kept in captivity outside reminiscent of various small dabbling Australia, and since there was such a pau­ ducks in their agility and manoeuvrability. city of behavioural information regarding Indeed, the Grey Teal Anas gibberifrons them, I planned a trip to Australia for the is often associated with Pink-ears, and the primary purpose of learning whatever was two species exhibited much similarity in possible regarding the behaviour and pro­ flight. The long, flap-tipped bill is con­ bable relationships of these birds. In spicuous in flying Pink-ears, and is often addition, I wanted to observe and film the tilted slightly downwards, while the wings displays of the Musk Duck and Blue-billed alternately flash their white undersides and D uck Oxyura australis, for, although brown upper surfaces. No speculum is some accounts of the behavior of these present, but the secondaries and inner species do exist, I wanted to obtain detailed primaries do have a pale whitish trailing information for future comparison with the edge. Another plumage feature visible in South American and African stiff-tails. flight that I had not anticipated is the white M y notes on the displays of the Australian crescent on the upper tail coverts immedi­ stiff-tails will be published separately ately in front o f the brown tail. This feature (Johnsgard, in press), and only some resembles the similar crescent patterns of general observations on them will be made whistling ducks and geese which, like the here. Pink-ear, lack specula or contrasting upper wing patterns. I therefore wondered if this P in k -eared D u ck plumage feature (which is not found in any The Pink-eared Duck is regarded as a other dabbling ducks) might be of signifi­ reasonably common bird in southeastern ance in coordinating the flock movements Australia, and it occurs generally over the o f flying birds. continent as well. It is highly nomadic, Because the birds called almost con­ however, and numbers in a particular area stantly in flight (and a flock of Pink-ears may vary enormously from year to year. I could often be recognized by sound long observed several hundred Pink-ears on the before they could be visually identified), it Metropolitan Farm, 30 miles southwest of is almost impossible to describe the flight Melbourne on 13th July, and had under call as anything more than a clear, tittering daily observation a flock of nearly 500 birds whistle. I am uncertain whether both sexes at Kangaroo Lake, near Kerang, northern can whistle, but at least the male has a pure Victoria, from 16th July to 7th August, whistled note. The trachea of the female 1964. shows no obvious specializations for M y first impression of the species was whistling, but H. J. Frith informed me that that the duck is smaller and stockier than I the tracheal bulla o f the male is very similar had visualized, and that the tail and rump to that of the Grey Teal. Warham (1959) are held quite high in the water while describes the male’s call as a ‘loud fluty

74 THE WILDFOWL TRUST cry,’ and that of the female as a purring each other’s wake as they rotate in a tight note. I observed an apparent female utter circle. Occasionally, even a single bird will a sharp., rapid series o f ‘W he-he-he’ notes attempt to feed in its own wake. This type towards another bird, which, although not of feeding is obviously most effective when a true whistle, was quite unlike the typical performed by two birds, and thus accounts female dabbling duck calls. for the tendency of large flocks to break up Displays described in the literature for into apparent pairs when foraging in this the Pink-ear fall into two categories : head- manner. However, it would be presump­ bobbing displays (Scott, 1958, Hobbs, tuous to suggest that such foraging is 1957) and ritualised foraging displays totally lacking in social significance, for I (Shanks, 1953). Among the typical dab­ often observed that when an ‘outsider’ bling ducks, the shoveler group is noted attempted to enter such a feeding circle, for its conspicuous head-bobbing and there was a pronounced chin-lifting, clearly ‘mock-feeding’ displays (Lorenz, 1951- hostile, response from one or both of the 1953), and I was therefore eager to com­ participants. This upward bill-tilting (from pare the behavior of the Pink-ear with that 45 to 60 degrees above the horizontal), of the typical shovelers. accompanied by neck-stretching and a I first observed the communal foraging series of rising ‘we-we-we-we-we-whew’ of Pink-ears on July 16 at Kangaroo Lake, notes, closely resembled chin-lifting of but I was never sufficiently close to the shovelers and various other dabbling ducks. birds to film this interesting behavior No lateral inciting movements were pattern. In the typical shovelers, commu­ observed, and if an inciting display does nal foraging (unritualised, and performed occur in the Pink-ear, it probably has this by both sexes at all times of the year) same chin-lifting form as found in the consists of several birds swimming head- shovelers. to-tail, with each bird dabbling in the wake Two probable male displays were of the one before. Such foraging groups observed. Sometimes, during a pair’s may become circular when the leading bird foraging, a presumed male would suddenly begins to follow the hindmost individual. draw its bill out of the water, stretch its Ritualised foraging, or ‘mock-feeding’, is neck into an erect posture, and momen­ performed by males to females and consists tarily hold this stiffened, alert position of apparent dabbling in front of or beside before resuming foraging. The posture the female, without much forward swim­ reminded me of the ‘At-attention’ (Wall, ming, and often terminated by calling or 1961) display of various dabbling and up-ending. In the Pink-ear, communal perching ducks. This same erect posture foraging takes a different form, for the was also often assumed after a curious bill- birds tend to feed in pairs, and only rarely tossing call, which was performed only by in trios or larger groups. Further, each bird birds I judged to be males. In this display tends to keep its body parallel to its the bird would toss its bill upwards and partner, but turns its head towards its rapidly lower it while its neck was held partner’s tail, and the two birds forage in vertical, and a hoarse and cat-like ‘Who-

AUSTRALIAN ANATIDAE 75 ee-oo’ call was uttered. At times the call F reckled D u ck would be repeated once or twice in rapid For nearly ten years I had cherished a succession. Although the call appeared dream of studying the Freckled Duck in frequently directed to presumed females, life, for although this bird is among the at other times it seemed to be uttered at least impressive of all the Anatidae in random. Suggesting the possibility that this beauty, so little is known of its biology that behaviour is a major pair-forming display is I have long considered it the most import­ the fact that birds which uttered this call ant species of waterfowl to be investigated were often immediately attacked, or at least behaviorally. threatened, by other probable males. I also My suspicions that the Freckled Duck saw one possible male display performed as was something other than just an aberrant a presumed female swam past: a lateral dabbling duck were aroused by the skeletal head-shake (made conspicuous by the studies of Verheyen (1953) who, in spite of enlarged bill), followed by a dorsal preen­ his doubtful taxonomic interpretations, ing in the region of the scapulars. completed a fairly comprehensive survey A few other behaviour observations might of skeletal variations in waterfowl. He be of interest. Lateral head-shaking was the concluded that the Freckled Duck’s only pre-flight movement I observed. Up­ anatomy was sufficiently distinctive to ending was never observed by me, but two warrant ‘family’ status (corresponding in birds were seen to dive using opened Verheyen’s treatment roughly to the tribes wings) in the course of preening and bath­ of Delacour), but exhibiting affinities with ing. both the whistling ducks and the pochards. The Lowes have recently observed three The large number of ‘primitive’ features copulations, involving two different pairs, found in the Freckled Duck cannot be which indicate that the species diverges easily reconciled with the generally spe­ markedly from Anas in its copulatory cialised characteristics of the dabbling behaviour. In each case the male flew in ducks, and I was forced to conclude (1960, from a distance and, as it landed about 1961a), that the species probably should be twelve yards from the female, greeted her placed in the subfamily Anserinae, either with a loud flute-like whistle, to which the in the Anserini or, more probably, in a female replied similarly. The male im­ separate tribe ‘Stictonettini’. In the mediately swam to the female and, with no absence of available anatomical specimens, apparent preliminary displays, mounted Woolfenden (1961) came to similar tenta­ her. Following a rapid copulation both tive conclusions, but felt that the whistling birds performed rapid, energetic dabbling ducks might represent the Freckled Duck’s and “head-tossing” movements (seven and nearest relatives. The contrasting downy ten in two cases counted), terminating with of the whistling ducks are highly a single preening movement on the breast, distinctive and different from the weakly wingflapping, and finally swimming about patterned or uniformly coloured young of in small circles and up-ending as if feed­ swans and geese, but the absence of a ing. How much of this postcopulatory description of the downy young of the behaviour represents actual display is Freckled Duck made this source of evi­ uncertain, but in any case these obser­ dence unavailable until recently, when vations suggest that a very distinctive Frith (1964a, 1964b) described the downy copulatory behaviour exists in Pink-eared plumage. Interestingly, the downy young Ducks. of Freckled Ducks show no similarity to In summary, its behaviour suggests that those of any dabbling ducks, but rather are the Pink-ear belongs in the large assemb­ a uniform silvery grey throughout. Among lage of dabbling ducks but that it is not the ducks only the downy young of the necessarily extremely closely related to the Musk Duck nearly approaches that of the typical dabblers. Although the body form, Freckled Duck, and the cygnets of Black foraging adaptations, and, to some extent, and Mute Swans (Cygnus atratus and the displays of the Pink-ear are reminiscent C.olor) are even more similar. Thus, of shovelers, it is probable that these traits additional evidence for including the are simply splendid examples of convergent Freckled Duck in the subfamily Anserinae evolution in which similar ritualised is now at hand. behaviour patterns have evolved from Although my major purpose in going to independent evolutionary sources. Pre- Australia was to locate the Freckled Duck, copulatory behaviour has not yet been I had been forewarned by nearly everyone adequately described. Tom Lowe’s ob­ servations suggest that an Anas-like pre- I contacted that the rarity of this species copulatory head-pumping is absent and and its unpredictable movements pre­ that the postcopulatory behaviour may be cluded any real hope of locating wild birds. unusual as well. My optimism was further weakened upon

76 THE WILDFOWL TRUST corresponding and talking with several of in gradually declining numbers on the lake Australia’s most active ornithologists, some until I left the area on 7th August, by of whom confided that they had never seen which time nearly all of them had dispersed the species and politely wondered how I and vanished. The following observations might not only locate it but also study its are based on this single flock, and include behaviour in the relatively few weeks I had at my disposal. Although a plea for assist­ several points of doubtful significance, ance in locating Freckled Ducks had gone mentioned only because of the rarity of out from Roy Wheeler to the members of concrete information on the species. the Bird Observers Club of Victoria, no promising responses resulted, and I there­ General appearance fore decided to begin searching areas such Although my first impressions of flying as the Kerang region, where records of Freckled Ducks was to be reminded of Freckled Ducks were fairly numerous and Grey Ducks, I later decided that they have where Vic and Tom Lowe had promised an even stronger similarity on the wing to to help me try to locate the species. Gadwall Anas streperà. Like Gadwall, The Lowes had previously recorded they have a silvery white underwing lining Freckled Ducks in seven different months and abdomen, contrasting with a rather of the year, with a maximum number of uniformly dark breast, head and upper 200 recorded in September 1957. Before surface (but lacking the white speculum of my arrival some preliminary searches on the Gadwall). Their pattern of flight is their part had not produced any Freckled generally like that of a dabbling duck, being Ducks, and so it was without a high degree both swift and somewhat erratic. The of optimism that we set out on 19th July to accompanying table shows the rate of search in a few likely spots. wingbeats determined from cine footage One promising place was Cullen’s Lake, for various conditions of flight, as com­ where Harry Wright of the Victoria pared with typical dabbling and whistling Fisheries and Wildlife Department had ducks. Although Frith (in Delacour, 1956) observed a few birds some weeks previ­ states that the wingbeat is normally slow ously. It was a cold, windy day, with and bittem-like, I did not find this to be periodic showers, and as we scanned the the case. Rather, the rate of wingbeats is choppy waters I could see only Musk almost as rapid as a M allard’s (Anas platy­ Ducks, Pink-ears and a few Grey Teal. rhynchos), and faster than a Fulvous After fruitlessly searching an area of shore­ Whistling Duck’s (Dendrocygna bicolor). line and shallows well lined with protrud­ On the water the birds present a profile ing fence-posts (a favourite Freckled Duck similar to that of a typical dabbling duck, roosting site), I suggested to Tom that we with the tail held somewhat out of the try counting the sex ratio of the Musk water (but not nearly as high as in the Ducks. As we walked up to the shore to Pink-ear). Except when alert and ready to improve our view, we flushed a large flock fly, the head and neck are not held very of ducks that had been resting in a shallow high above the body; indeed, the birds bay hidden from my vision. As the flock generally present an impression of being flew away I scanned it with unbelieving rather sleepy, with the bill held only eyes; although the birds appeared nearly slightly above the level of the breast. The the size of Grey Ducks Anas superciliosa head appears surprisingly large, but this is and were nearly as dark, I could see no the result of the elongated feathers in the trace of a metallic speculum. Tom ended occipital region, resulting in a short crest my uncertainty with a shout that they were and a distinctly triangular head profile. indeed Freckled Ducks ! The flock of This distinctive head profile is an excellent approximately 180 birds landed near the field mark for sitting birds, and allows for middle o f the lake, but gradually swam back easy distinction from such species as Grey toward the lee shore. The birds remained Ducks. Although the bill is high and robust

Table I. Rate of wingbeats in Freckled Ducks as determined from films total wingbeats total seconds ave. wingbeats¡second F reckled Duck losing altitude 58 7.7 7'5 sustained flight 91 11'4 8-0 taking off 41 3 ’9 10-6 Mallard sustained flight 75 8 7 8-6 Fulvous Whistling Duck sustained flight 47 6-8 6-8

AUSTRALIAN ANATIDAE 77 at the base, the culmen profile is very General Behaviour concave, and the outer part of the bill is The similarity of Freckled Ducks to strongly flattened and almost spatulate. dabbling ducks in flight has been men­ The nail is fairly sharp and, curiously, is tioned, but I noticed that in leaving the slightly recurved as in the typical stifftails water Freckled Ducks appear unable to (Oxyura). In fact, the total bill shape is spring directly out of the water in the probably more like that of an Oxyura than manner of dabbling ducks, and instead run o f a dabbling duck. for several feet along the surface. By in­ Sexual differences are minor and did not vestigating my films I verified this beha­ allow me to determine the sex ratio of the viour and determined that in four cases flock. Birds that were undoubted males had that could be analysed up to nine steps a more distinct occipital crest, a tendency (average seven) were taken while clearing toward a blackish rather than brownish the water. It is probable that variation does head (especially on the cheeks), and a vari­ exist here, depending on wind velocity and able amount of red on the bill. This last urgency of take-off, but it was an unex­ point is one which has been disputed (Frith, pected observation and seems worth not­ in Delacour, 1956), but there can be no ing. doubt that a brilliant, sealing-wax red Although I observed Freckled Ducks colour appears at the base of the bill flush literally dozens of times, often when (extending to a point just beyond the frightened by Whistling Eagles Haliastur nostrils) of males during the breeding sphenurus or White-breasted Sea Eagles season. In the flock I observed, only two Haliaeëtus leucogaster, I never heard any birds had brilliant red bills, while nearly 20 alarm calls by any of the birds either while more had variable indications of red on the taking off or as they were milling about bill. Evidently the colour is retained for a overhead. This is quite different from the very short time; Vic Lowe informed me situation in typical dabbling ducks, in that he has not observed it in hundreds of which both sexes usually exhibit alarm Freckled Ducks he has seen shot during calls. the hunting season. This seasonal occur­ Another surprising point was that, rence of bill colour is of interest, and it, although Freckled Ducks were usually plus the tendency of the male to assume much more numerous than other species darker, more distinctly crested head than with which they associated, mainly Aus­ the female’s, belies the generality that tralian White-eyes Aythya australis, Freckled Ducks do not exhibit sexual Shovelers Anas rhynchotis, Pink-ears, and dimorphism. In this regard, therefore, they Grey Teal, these other species seemed cannot be considered wholly typical much more alert than the Freckled Ducks members of the subfamily Anserinae and were always the first to flush at the (although some swans show slight amounts approach of possible danger. This evident of sexual dimorphism). Mr. Harry Wright tameness (or stupidity) of Freckled Ducks informed me that he believes the male loses was impressed upon me the second day of its crest and blackish head during the non­ my observations, when I proceeded to set breeding season, suggesting at least a partial up a wood and burlap blind along the double moult, which is also an anatine shoreline some 100 yards from the birds’ characteristic. Aside from the Freckled usual foraging area. Deciding that the only Duck, only some of the stiff-tails (Oxyura way to set up the blind was to march and Heteronetta) display a conspicuous brazenly down and get the job done with­ seasonal variation in bill colouration, and out regard for the likelihood of flushing the the situation in the Black-headed Duck birds, I began to pound in the supporting Heteronetta atricapilla is remarkably like stakes in full view of the entire flock. Al­ that of the Freckled Duck. The male though the Coots Fulica atra and other Black-headed Duck’s bill is very similar in duck species had flushed at my first appear­ shape to that of the Freckled Duck, being ance, the Freckled Ducks remained, and high at the base, flattened at the tip, and about 30 of their number left the main with a recurved nail. Furthermore, it flock and swam directly toward me, stop­ develops a bright orange to red colour at ping and watching when they reached a the base of the bill during the breeding distance of some 30 yards from me. I season. Other notable similarities of males frantically finished the blind and disap­ of the two species include their blackish peared behind it, at which time the birds heads, greyish to brownish body plumages, lost interest and swam away in a leisurely the absence of wing specula, and rusty- maimer! It is possible that this apparent brown undertail coverts. The downy stupidity is the main basis for the collo­ plumages, however, are very dissimilar, quial name ‘Monkey Duck’ ; however, and the females are likewise quite unlike. Harry Wright has suggested (personal com­

78 THE WILDFOWL TRUST munication) that the tendency of the birds Vocalisations to climb out of water and perch on floating Little has been recorded concerning the logs or flooded posts and timbers might calls of Freckled Ducks. Delacour (1956) also account for this name, which is com­ mentions only a pig-like grunt and a cat­ monly used by Victorian hunters. like mewing note, and so I wanted to try to During most of the day, the birds swam resolve this point. In spite of attentive about in flocks of 50 or so near the middle listening on my part, it was not until 22nd of the lake, resting or sleeping and showing July that Tom Lowe and. I definitely no interest in foraging. The lake is a identified a call as that of the Freckled shallow one, possibly ten feet deep at most, Duck. This was a series of rather pro­ and has an extensive growth of aquatic tracted, muttering notes, which we agreed plants which often break and drift in to was a ‘hissing, raspy murmur’, scarcely form windrows along the shoreline. The audible at a distance of over 30 or 40 yards. only foraging I observed occurred very We also heard several sharper, flute-like close to shore, while the ducks swam or calls which, we believed, emanated from the stood in shallow water and immersed their Freckled Ducks, but we couldn’t locate the bills just under the water’s surface. I individuals responsible. H. J. Frith (per­ observed neither up-ending nor diving, but sonal communication) has also heard a doubtless at least the former is used occa­ number of different calls in his captive sionally, since Hobbs (1957) reported up­ Freckled Ducks. It is certain, however, that ending by birds feeding in about two feet Freckled Ducks are similar neither to of water. Although the birds were obvi­ dabbling ducks nor to whistling ducks in ously filter-feeding, I have no real idea of their vocalisations. Considering the almost what they were consuming. H. J. Frith complete absence of visual display struc­ (personal communication) believes that tures, one is forced to conclude that Freckled Ducks feed largely on plankton­ auditory display specialisations must exist. sized food particles. The flattened and There is a slight sexual dimorphism in the concave-shaped bill may have functional structure of the trachea, for although both significance here, by allowing the tip of the sexes lack a tracheal bulla, the male does bill to filter-feed while still keeping the exhibit two enlargements of the tracheal nostrils above water. While swimming tube (Campbell, 1899). from the middle of the lake to the foraging area along shore the birds showed a strong Sexual Behaviour and Displays tendency to ‘follow the leader’, swimming Considering the large number of birds in single file at a speed determined by the under observation, the relatively long (three leading bird. week) period they were studied, and the Although I did not personally observe fact that, judging from bill colouration, at nesting, some notes regarding nests and least some of the males were clearly coming young were sent to me from Air. Len into breeding condition, it might be Harvey. He mentions finding clutches of expected that pair-forming activity would seven and nine eggs, and seeing three have been frequently observed. Yet, in broods numbering from seven to nine spite of these favourable conditions, I saw young. In one instance, both parents were very little that could be interpreted as pair- present with the young while in the other forming behaviour and thus was led to two, only the female was seen. Thus, it conclude that such activities must be remains uncertain whether both sexes poorly developed and inconspicuous at normally participate in incubation and best in Freckled Ducks. An inconspicuous brood care. courtship is typical in the subfamily

AUSTRALIAN ANATIDAE 79 Anserinae, for whistling ducks appear to many uncertainties remain to allow an lack elaborate ‘courtship’ postures, and unequivocal statement of the Freckled among the geese and swans the ‘triumph Duck’s relationships, none of my observa­ ceremonies’ appear to play a major role in tions suggest that the Freckled Duck is an pair formation. In the true ducks of the aberrant dabbling duck, for it apparently subfamily Anatinae there is usually con­ exhibits none of the typical specialised siderable dimorphism in the behaviour of behavioural features of that group. Further­ the sexes, and variably complex displays more, although much of what I observed are exhibited by the males. could be interpreted as indicating that the In the Freckled Ducks I could see no Freckled Duck is an extremely generalised indication of pair bond attachments bet­ species with many primitive and apparently ween individual birds, and no tendency for anserine features, there is no real justifica­ small groups to separate out as courting tion for including the species in either the parties, as might be expected among dab­ whistling duck tribe or that of geese and bling ducks. I particularly looked for, but swans. Finally, and this came as a personal failed to find, a female inciting display, surprise, a few of the features of Freckled which is of widespread occurrence in the Ducks are reminiscent of the stiff-tails and subfamily Anatinae (Johnsgard, 1962). particularly the Black-headed Duck. There­ Likewise, I looked for evidence indicating fore, I am led to the conclusion that the the presence of a triumph ceremony similar only reasonable taxonomic procedure is to to that of geese or swans, and the only erect a monotypic tribe (Stictonettini) for clear-cut display I observed might possibly the Freckled Duck, and to include it be interpreted as such. This display, seen within the subfamily Anserinae, as I first on several occasions, is a rapid and extreme suggested in i960. Nonetheless, the several vertical neck-stretching, associated with obviously duck-like features of the species gaping (and probably calling), ptrformed suggest that the bird is descended from by one bird towards another while facing stock that probably gave rise to the true it, and to which the other responds in the ducks of the subfamily Anatinae, and same manner. The display is preceded by particularly the stiff-tails. A detailed forward neck-stretching and gaping by one anatomical comparison of the Freckled bird toward the other, in what would Duck and the Black-headed Duck might appear to be hostile posture. In one case a shed some light on this possibility. Of red-billed male performed this display to greater importance than the simple relega­ an apparent female, who then responded tion of this species to a convenient taxono­ by the vertical neck-stretching. This mic niche is the need for a realisation o f the behaviour could most readily be interpreted Freckled Duck’s evolutionary status as a as a mutual threat display, but it is similar surviving generalised form that needs to in form to the triumph ceremonies of some be studied further in all respects, and to swans and geese. The general absence of the best of our abilities we should protect colour patterns on the wings and body and it from its present danger of extinction. their concentration on the bill fits the supposition that Freckled Duck displays M u sk D u c k probably mainly involve head movements The Musk Duck is a common species over and possibly vocalisations, as in the much of southern Australia, and can triumph ceremonies of swans and geese. frequently be observed off the coastline in However, I did not observe prior attacks winter. Most of my observations were or threats towards other individuals of the obtained at Kangaroo and Cullen’s Lakes, type which usually elicit triumph cere­ where several hundred of these birds were monies in swans and geese. present throughout my stay. According to Unfortunately, no copulatory behaviour Vic Lowe Musk Ducks are seen at Kan­ was observed, and a knowledge of copula­ garoo Lake throughout the year, and young tory displays, particularly precopulatory have been sighted from as early as Septem­ displays, would be of the greatest value in ber to as late as April. evaluating Freckled Duck relationships. In spite of the evident abundance of the Should a goose-like mutual head-dipping Musk Duck, information on its behaviour is precopulatory display be present, this surprisingly scanty and contradictory. would strongly favour the hypothesis of Thus, although the Musk Duck is reputed anserine affinities, as would the occurrence to fly almost only at night, Vic and Tom of a mutual postcopulatory display. How­ Lowe have observed adults of both sexes ever, some of the true ducks exhibit fly on numerous occasions, and I observed head-dipping and mutual postcopulatory a total of four different birds in flight. In displays, and so even these findings would each case, the birds, all females, flew have to be viewed with caution. towards shore from some distance out in In summary, although I believe that too the lake, first pattering over the surface

80 THE WILDFOWL TRUST some 30 to 40 yards, then clearing the the absence of marked birds, no definite water by a foot or two, and flying 100 yards evidence of pair relationships could be or more before ‘crash landing’ into the established, but I seriously doubt that any calmer water near shore. In each instance, pair bond exists, and believe that males are the wind was blowing off shore at an completely promiscuous in their contacts estimated 20 to 25 miles per hour, but Tom with females. Unlike the pair-forming Lowe has observed Musk Ducks take off behaviour of other waterfowl, in which from calm water and fly as high as seven males actively seek out and display to un­ feet above the water surface. paired females, male Musk Ducks typically The calls of theMuskDuckhave similarly begin their displays alone, and apparently been disputed and variously described. The rely on the combination of loud splashes whistling call of the male, a clear penetrat­ and vocal noises to attract females. This ing note rather similar to that o f the W hite- importance of auditory signals may explain backed Duck Thalassornis leuconotus, has the tendency for display to occur in total been described by several observers. Mack darkness, and the absence of bright colour­ (1959) describes it as a ‘Chee-ip’ or ation on male Musk Ducks. The sounds of ‘Chee-eep’, and he heard it only from a displaying male are clearly effective in wattled birds (thus, adult males). Likewise, attracting both females and other males ; I I heard this call only in birds that appeared have seen Musk Ducks interrupt preening to be adult males, and, furthermore, I or sleeping to swim promptly toward the observed it only in association with a sound of a displaying male that was com­ specific display I have termed the Whistle pletely hidden from view around a point Kick (Johnsgard, in press). Tom Lowe tells and over 100 yards away. Why other males me that he is certain he once heard the should be attracted to displaying birds is whistle produced by a bird possessing no uncertain, but they showed a keen interest evident wattle, and Vic Lowe twice in watching such birds, and occasionally observed a male utter a whistle when it saw approached quite close. Displaying males a hawk flying overhead. Interestingly, the would usually not attack other ‘onlooker’ Lowes have heard this note whistled every males unless they approached too closely month of the year, and during practically the females that had also been attracted to all hours of the day and night. During the the display. time I was at Kangaroo Lake it was Like other stiff-tails, Musk Ducks are unusual to go outside at night and not hear excellent divers, and while foraging much a Musk Duck whistling in the distance. time is spent under water. I timed one The note can be readily heard for a half mile undisturbed foraging male that spent an or more under favourable conditions. average of 24-4 seconds under water in 14 The other sound commonly attributed consecutive dives (range 15 to 32 seconds), to the male Musk Duck is the ‘plonk call’, while in the intervening 13 periods he was which Gould fittingly described as resemb­ surfaced an average of 15-5 seconds (range ling the noise produced by a large object 10 to 25 seconds). When frightened the falling into a deep well. Although there is submergence time is much greater. little disagreement regarding the nature of There can be little question that the the sound, its origin is far less certain. Musk Duck is a stiff-tail and that its Some authorities suggest it is vocally nearest relatives comprise the genus produced, while others have attributed it Oxyura. However, I was surprised by the to the slapping of the tail or the feet on the similarity of the whistled notes of Musk water. I am convinced that the sound is Ducks and White-backed Ducks, and made by the outstretched webs of the feet impressed by the remarkable similarity of as they slap downward on the water follow­ the general plumage patterning of these ing one of the several types of kick displays two species, a fact which Scott (1958) had (Johnsgard, in press). also noticed when he first observed the To my knowledge no calls have been birds. attributed to the female, and I personally heard none, but the Lowes and Mr. David B lu e-b il l e d D u ck Dent heard a female accompanied by a The Blue-billed Duck is relatively rare in well-grown young utter a gabbling note as Australia, and is limited as a breeding bird an apparent warning call. Mr. Lowe to the permanent swamps that are well- thought that the call was similar to the lined with emergent vegetation. Although barking call of a Crested Grebe Podiceps it nests in the Kerang area, it is far more cristatus. abundant as a winter visitor. During July There has been some speculation as to and early August it was easily the most the type of pair bond, if any, found in the common of the ducks on Lake Kangaroo. Musk Duck. I made a few sex ratio counts, On30th July'I counted over 1,600 Blue-bills and found an approximately equal ratio. In along a mile of shoreline centred on the

AUSTRALIAN ANATIDAE 8 l Lowes’ property, and, considering that the rently poorly developed, as Delacour (1959) lake is approximately four miles in length, suggests. Shanks (.1954) heard a male utter the actual population was doubtless several a ‘quack’ like a Grey Duck, as he attacked thousand. These flocks typically arrive in a female. Tom Lowe has heard a repeated early winter, but Vic Lowe informed me ‘Kek-kek-kek . . .’ or ‘Bub-bub-bub . . .’ that there is great variation in numbers, note, but is uncertain which sex was res­ with few birds arriving in some years, and ponsible. This call probably corresponds in any case most disperse prior to the to a ‘Teh-teh-teh . . .’ which Tom and I nesting season. heard females utter when they were gaping According to Delacour (1959) there is toward males, and which is quite different no record of an eclipse plumage in Blue­ from the squeaking note uttered by female billed Ducks, but I am convinced that a North American Ruddy Ducks Oxyura j. female-like winter plumage does exist. The jamaicensis under the same circumstances. Lowes have noted that in early winter flocks of Blue-bills, the female-like birds Acknowledgements may outnumber obvious males by as much This research was conducted under a as 20 to one, but that this ratio rather National Science Foundation grant (No. rapidly drops towards equality. In late GB 1030), as part of a general study of July I made various sex ratio counts in Anatidae behaviour and relationships. which males always predominated (cumu­ Although numerous Australians went to lative total 445 males to 266 females), but great lengths to assist me, I am particularly many of the males showed varying degrees indebted to the Vic Lowe family, whose of female-like feathering. At the time I left assistance was invaluable and whose Kangaroo Lake (7th August) a minority of hospitality will never be forgotten. Mr. Roy the males had assumed the brilliant blue Wheeler’s enthusiastic assistance in plan­ bill colour typical of breeding birds, but ning my itinerary allowed me to make the pair-forming activity was becoming quite best possible use of my time. Mr. Max intense. The nesting season of Blue-bills is Downes and Mr. Harry Wright of the probably more restricted than that of Musk Victoria Fisheries and Wildlife Department Ducks; the Lowes have observed young in were extremely helpful and spared no the months of November, December, efforts in making my trip a success. Finally, March and April, while Wheeler (1954) I would like to thank Dr. D. F. Dorward reports the nesting season at Ballarat and Professor A. J. Marshall of Monash (central Victoria) extends from November University for allowing me to use the to early February. Department of Zoology and Comparative Vocalisations in the Blue-bill are appa­ Physiology as a base of operations.

Literature Cited

BOETTICHER, H. 1943- Die phylogenetisch-systematische Stellung von Anseranas. Zool. Anz. 142: 55- 58- Cam pbell, A. J. 1899. On the trachea o f the Freckled Duck o f Australia (Stictonetta naevosa). Ibis ser. 7, vol. 5: 362-364. DAVIES, s. J. J. F. and H. J. f r i t h . 1964. Some comments on the taxonomic position of the Magpie Goose Anseranas semipalmata (Latham). Emu 64: 264-272. DELACOUR, J. 1 9 5 4 - 1 9 6 4 . The Waterfowl of the World. 4 vols. Country Life, Ltd., London. f r i t h , H. J. 1 9 6 4 a . Taxonomic relationships of Stictonetta naevosa (Gould). Nature 202: 1352. FRITH, H. J. 1 9 6 4 b . The downy young of the Freckled Duck Stictonetta naevosa. Emu 64: 42-47. HOBBS, J. N . 1 9 5 7 . Notes on the Pink-eared Duck. Emu 57: 263-268. johnsgard, P. A. i960. Comparative behaviour of the Anatidae and its evolutionary implications. Wildfowl Trust n th Ann. Rep. : 31-45. johnsgard, p. a . r96ia. The of the Anatidae - a behavioural analysis. Ibis 103a : 71-85. JOHNSGARD, P. A. 1961b. The breeding biology of the Magpie Goose. Wildfowl Trust 12th Ann. Rep.: 98-103. johnsgard, p. a. 1962. Evolutionary trends in the behaviour and morphology of the Anatidae. Wildfowl Trust 13th Ann. Rep.: 130-148. johnsgard, p. a. (In press). Behaviour of the Australian Musk and Blue-billed Ducks. Auk: Lorenz, k. z. 1951-1953. Comparative studies on the behaviour of the Anatinae. Avie. Mag. 57: 157-182; 5S: 8-17, 61-72, 86-94, 172-184; 59: 24-34, 80-91. m a c k , d . i960. Calls of the Musk Duck. S. Aust. Orn. 23: 31. m i l l e r , w. DE W ITT. 1919. Notes on the structure of Anseranas. Auk 36: 562-564. SCOTT, p. 1958. Notes on Anatidae seen on world tour. Wildfowl Trust 9th Ann. Rep. : 86-112. shanks, d. 1953. Random notes from south-western Victoria. Emu 53: 276-279. shanks, D. 1954. A further note on Blue-billed Ducks. Emu 54: 76. Si b l e y , c. g . i960. The electrophoretic patterns o f avian egg-white proteins as taxonomic characters. Ibis 102: 215-284. TYLER, c. 19 6 4 . A study o f the egg shells o f the Anatidae. Proc. Zool. Soc., London 142: 547-583.

82 THE WILDFOWL TRUST v e r h e y e n , r . 1953. Contribution à l’ostéologie et la systématique des . Gerfaut 43 (Suppl.) : 373- 497- WALL, w . V. d. 1 9 6 1 . Die Ausdrucksbewegungen der Rapente, Anas capensis Gmelin. J. Orn. 102 2 4 - 2 7 . WARHAM, j. 1959. The nesting of the Pink-eared Duck. Wildfowl Trust çth Ann. Rep.: 118-127. w h e e l e r , j. r . 1953. Notes on the Blue-billed Ducks of Lake Wendouree, Ballarat. Emu 53 : 30-32. wooLFENDEN, G. E. 1961. Postcramal osteology of the waterfowl. Bull. Florida State Museum 6 : 1 - 1 2 9 .

Returns from »teller’s Eiders banded in Izembek Bay, Alaska ROBERT D. JONES, Jr. Aleutian Islands National Wildlife Refuge Summary The author has recorded observations of a large wintering population of Steller’s Eiders in Izembek Bay for eight years. From 1957 through 1962 the birds arrived in early fall to complete the post nuptial moult in the Bay. Advantage was taken of the flightless period to band 833 of the eiders. Methods are described along with observations of the bird’s behaviour. In 1963 and 1964 the moult was completed elsewhere on the migration route and the population arrived nearly three months later that before. Returns from the Soviet Bird-Ringing Centre indicate the moult to have taken place in Siberia, the principal nesting ground of the Steller’s Eider. The remarkable fact is that in some years many of these birds migrate upwards of 3,200 kilometres before the post nuptial moult. Wintering populations of Steller’s Eiders with about 30,000 Emperor Geese Anser Polysticta stelleri are known from the canagicus and 70,000 Black Brant Branta waters of Kodiak Island west along the south bernicla orientalis. coast of the Alaska Peninsula and the The arrival date of the Steller’s Eider eastern Aleutian Islands (Gabrielson and population in Izembek Bay in fall has Lincoln, 1959). This writer has observed proven strikingly variable. Some years them in the area of the western half of the most, if not all, of these birds arrive in Alaska Peninsula where they are known August to perform the post nuptial moult colloquially as ‘Scotchies’. A considerable in the three lagoons of this area, while other segment of this population, aggregating years they arrive almost three months later, roughly 200,000 birds at its peak, moves in having completed the moult at some other and out of three large lagoons on the north point on their migration route. For six coast of the Peninsula, dependent on years, 1957 through 1962, the moult was freezing and thawing conditions. These are conducted in these lagoons but in 1963 and Nelson Lagoon, Izembek Bay, and Bech- 1964 only about 5% of the population evin Bay (at the north end of Isanotski appeared until after the moult. We do nor Strait). These, together with the interven­ have a record of the arrival date for 1963, ing coast form the western end (about 125 but in 1964 between sunset 6th November miles) of the Alaska Peninsula. McKinney and midmorning of 9th the population (1959) has recorded his observations of appeared in Izembek Bay in an avalanche waterfowl in these areas. The peak popula­ migration. tion of the little Steller’s Eider is reached in In 1961 we began banding these birds this area in April, when about half of them during the flightless period. At low tide are in Nelson Lagoon and the other half are Izembek Bay becomes a pattern of exposed divided between Izembek Bay and Bech- mud and sand bars with channels running evin Bay. The peak occurs on the eve of between them. We found that the flocks o f spring migration when these lagoons are flightless eiders could be driven up these ice-free and all other water areas farther channels from the deeper portions where north are still frozen. In Nelson Lagoon they normally rest, into the shallow water these birds are associated in April with at the channel’s head. Here they could be even larger numbers of King Eiders Soma­ held in a compact flock while a trap was teria spectabilis, and several thousands of installed, generally upchannel. When all Common Eiders Somateria mollissima v- was ready, the flock could usually be driven nigra, Scoters Melanitta nigra americana into the trap. Anyone who has engaged in and M. fusca dixoni and Old Squaw Ducks this type of endeavour will recognise that Clangula hyemaIis. In Izembek Bay and there is no certainty in capturing wild birds. Bechevin Bay they are associated in April These were day to day operations, taking

BANDING OF STELLER’ S EIDERS into account suitable weather, and sche­ strong in Nelson Lagoon and a roughly duled to complete the drive at about low equal number divided between Bechevin water. Large numbers of birds could not be Bay and Izembek Bay, the latter having the handled because the returning tide would larger number. flood trap and crew. The largest number In the fall of 1964 when again the large we ever captured was about 250, not all of numbers failed to materialise for the moult which were banded. The flocks are often we were more curious than concerned. By much larger, but we ‘cut out’ a group of this time we had received returns from the suitable size. Bird-Ringing Centre in Moscow, USSR We found that the males and females indicating that the bulk of the population tended to segregate in the moult, and our of Steller’s Eiders wintering in the Alaska catches were therefore predominantly of Peninsula area nest on the coast of the one sex or the other. We also found a Arctic Ocean in Siberia, some of them as distinct difference in behaviour under these far west as the delta o f the River Lena. This conditions between the two sexes. The is not particularly remarkable in itself for males proved relatively easy to handle, for we have Nelson’s (1883) account of large they generally did not struggle and re­ numbers about Cape Wankarem, Siberia, mained almost completely silent. The but it does seem remarkable that in six of females on the other hand struggled the eight recorded years some of these vigorously, squawking outrageously. When birds should travel upwards o f 3,200 kilo­ we handled a flock of females our hands metres before the post nuptial moult. It became severely scratched by their strug­ also seems remarkable that this behaviour gling. is not constant from year to year. A modest total of 833 birds was banded Thus far seventeen returns have been in 1961 and 1962, but little was accom­ received here, not counting our own recap­ plished in the next two years because there tures (numbering 43) or those taken by were few birds available in the moult. hunters in the immediate banding area. Of Accustomed as we were to very large these seventeen, one was recovered at Point numbers of Steller’s Eiders in Izembek Barrow, Alaska and the remainder came Bay during late August and early Septem­ from Siberia (Table I). The locations of ber we were dismayed when only about these recoveries in relation to the banding 10,000 appeared to moult in 1963. This site are shown in the map opposite. might seem to be enough for banding on Fourteen of the Siberian returns are our scale o f operations, and indeed it would from birds taken in June and July, two if they were all in one channel conveniently in 1962, one in 1964 and the rest in 1963. located for our purposes. But the Bay is The remaining two were killed at Cape large and the birds did not make them­ Wankarem 15th September, 1963. These selves available. They did, however, appear two are of especial interest because by this in time for the Christmas Bird Count and date in the six preceding years the Steller’s were present in April 1964 about 100,000 Eiders in Izembek Bay were nearing

Table I. Recoveries in Siberia of Steller’s Eiders marked in Izembek Bay, Alaska. All banded as moulting adults.

Date marked sex recovery site date recovered

Sept 3, 1961 M Near Nizhniye Kresty. 69°N, I 5 7 ° E . June 13, 1963 Sept 3, 1961 M 100 kilometres west of Khazach’ye. June 19, 1963 7I°N, I36°E. Sept 5 , 1961 F Delta of the River Lena. 73°N, I27°E. June 13, 1963 Sept 5 , 1961 M Delta of the River Lena. 73°N, I27°E. June 13, 1963 Sept 5 , 1961 F Delta of the River Lena. 73°N, X27°E. June 16, 1963 Sept 6, 1961 F Delta of the River Lena. 73°N, I27°E. June 16, 1963 Sept 6, 1961 M Near Nizhniye Kresty. 69°N, I57°E. July 10, 1963 Sept 6, 1961 M Chetyrekhstolbowyy Island, Ostrova June 7, 1964 Medvezh’i, East Siberian Sea. 7i°N , i 6i °E. Sept 19, 1961 M About 100 km east of Ambarchik, Magadan. July 4= 1962 70°N, i 62°E. Sept 19, 1961 M Cape Schmidt, Magadan. 69°N, I79°W. July 9, 1962 Sept 7, 1962 M Near Provideniya. 65°N, I74°W. July 5, 1963 Sept 7, 1962 M Near Wankarem. 68°N, I78°W. July 24, 1963 Sept 7, 1962 M 80 kilometres east of Pevek. 70°N, I70°E. June 00, 1963 Sept 10, 1962 F Cape Wankarem. 68°N, I78°W. Sept 15, 1963 Sept 10, 1962 F Cape Wankarem. 68°N, I78°W. Sept 15, 1963 Sept 10, 1962 F Delta of the River Lena. 73°N, I27°E. June 12, 1963

84 THE WILDFOWL TRUST completion of the post nuptial moult. late. One might suppose that this was also These returns suggest that the eiders true of Siberia. If so, it would explain the were moving eastward either slower or later late migration in 1964, but offers no than in the earlier years, but offer no clue explanation for the late one in 1963. as to why this disparity in behaviour should Clearly, if we are to answer these unknowns occur. In Alaska winter was slow to release we must look to a Soviet observer in its grip in the spring of 1964 and waterfowl Siberia. nesting was consequently two to four weeks

References GABRIELSON, I. N. and F. C. LINCOLN. 1959. The Birds of Alaska. The Wildlife Management Institute, pp. 212-214. m c k i n n e y , F. 1959- Waterfowl at Cold Bay, Alaska, with notes on the Display of the Black Scoter. Wildfowl Trust 10th Ann. Rep.'. 133-136. n e l s o n , E. w. 1883. The Birds of Bering Sea and the Arctic Ocean. Cruise of the Revenue- Steamer ‘Corwin1 in Alaska and the N.W. Arctic Ocean in 1881.

The prospects for wild geese in the Netherlands T . L E B R E T

Summary During their stay in winter quarters most species of wild geese are dependent upon the presence o f suitable roosts. Various types of roosts, the factors responsible for their presence, and their prospects are discussed. Several State programmes (the ‘Delta Project’ and various drainage plans) will endanger a number of roosts in the Netherlands within the next 25 years. White-fronted, Pink-footed and Bean Geese choose those localities where they may feed undisturbed rather than select special types of vegetation. Only the Brent Goose mainly feeds on the vegetation of the tidal zone of salt waters. The Greylag Goose shows a strong preference for tidal Scirpus fields along fresh and brackish estuaries. Drainage and reallotment schemes tend to open up the regions concerned for agricultural development, which invariably leads to an increase of disturbance and to the departure of the wild geese. In the Netherlands great numbers of wild geese feed on well-drained fields, provided they are left undisturbed. The effect of drainage and reallotment schemes can be partly offset by the institution of disturbance-free sanctuaries elsewhere. Since increasing numbers of wild geese will be concentrated on a decreasing acreage, the carrying capacity of the refuges must be in the focus of the protection plan for the wild geese in the Netherlands. In the Veerse Meer, the first estuary closed as a part of the Delta Project, a nature reserve will be managed as a special goose refuge by the sowing of grasses. Further refuges of this type will be urgently required as the Delta Project goes on.

BANDING OF STELLER’ S EIDERS 85 I. Introduction had either died out or had lost most of its The position of the wild geese in the importance. In all cases this was said to be Netherlands is a matter of concern since due to a decrease of the wild geese, attri­ Atkinson-Willes (1961) has pointed out buted to the effect of drainage works that in northwest Germany large areas carried out in the regions concerned. where great numbers of wild geese used to Formerly the meadows in these regions had winter have been permanently drained. been flooded from November to the Other areas in this region have been beginning of March. Parts of the areas were evacuated by the wild geese due to over­ completely inundated, while others were disturbance (Mörzer Bruijns, 1961). Most merely swamped. The geese were said to of these birds are now wintering in the have fed during the day in the swampy Netherlands, so that a big proportion of the parts of the area, concentrating at dusk on continental winter areas of the wild geese the wetter places. in Western Europe are now situated in this Generally speaking the goose areas in the country. The Dutch Government, however, interior of the Netherlands have been is carrying out several large-scale drainage evacuated. Those where the geese are still and reallotment schemes, while others are present or into which they have moved are in preparation. Moreover the Delta Project all coastal regions, with the exception of aims at the closure of the estuaries in the Central Friesland, where winter floods still southwest. Started in 1954, it is to be cover large areas. This suggests that the finished in 1978. All these activities of the presence of suitable roosts is of prime hydraulic and agricultural engineering importance for the distribution of wild services are a serious menace to the survival geese in their winter quarters, in so far as of wild geese in the Netherlands. they are not feeding in the tidal zone as A detailed study of the factors deter­ Brent Geese and Greylag Geese prefer to mining the distribution of the roosts and do. For such species roosts and feeding feeding grounds of the wild geese seems grounds are more or less identical. urgently required. All possibilities of Roosts being of such dominant import­ management in favour of the wild geese ance it seems necessary to have a clear should be applied in all reserves where this picture of the ecological components of the is possible. roosts in this country. For this reason the roosts which have so far been described ü . The roosts (Lebret, 1959, Philippona, 1962, 1963 and In the years 1941-1946 the present writer in litt., Den Daas, 1963, Timmerman, was collecting data for an inventory of duck personal communication) are listed below decoys in the Netherlands. This brought (Table I), classified according to their him into touch with other fowling prac­ origin. The list is, of course, not a complete tices, among which was the netting of wild one, but includes practically all important geese. In most of the regions where it had roosts. formerly been common practice, netting

Table I. Goose roosts in the Netherlands. Locations with more than 500 roosting geese are printed in capitals. Wildfowl reserves are indicated by an asterisk. GL Greylag Goose Anser anser WF White-fronted Goose A.a.albifrons BE Bean Goose A.f.fabalis and A.f.rossicus PF Pink-footed Goose A.brachyrhynchus BA Barnacle Goose Branta leucopsis A . Roosts on the Waddenzee Type: tidal sands and mudflats 1. LAUWERSZEE G L W F 2.* MUDFLAT off the BANTPOLDER BA 3.* Mudflat off the Noorderleegh WF B. Roosts in the Biesbos, on the Hollands Diep and the Haringvliet Type: sands and mudflat in tidal, fresh and brackish waters 4 - BIESBOS GL WFBE 5-* sasse PLAAT in the Hollands Diep GLWF BE 6. TIDAL MARSH CROMSTRIJEN GLWFBE 7 * VENTJAGERSPLATEN GLWFBE BA 8. BENINGEN GLWFBE 9- SANDBAR DIRKLANDSE SAS GLWFBE BA 10.* SCHEELHOEK GL WF BE BA

86 THE WILDFOWL TRUST C . Roosts in the salt water estuaries in the southwest Type: sandbars II. Z eehondenplaat in the Volkerak BE 1 2 . ROGGEPLAAT in the Oosterscheldt BA 13- s a n d b a r s in the Grevelingen BE 1 4 . * k a t s e P L A A T in the Zandkreek BE WF 15- HOGE p l a t e n in the Westerscheldt WF BE 1 6 . * s a n d b a r s in the upper part of the Westerscheldt WF BE D . Roosts 011 the Ijsselmeer off the province of Friesland Type : sandbars in static shallow fresh waters of the Ijsselmeer 17- SANDBARS off G AAST PF GL 1 8 . s t e i l e b a n k near o u d e - m i r d u m GLWF BA E. Roosts on the border lakes between the former coast of the Ijsselmeer and the new IJssel- meerpolders Type: shallow places in static fresh waters 19.* Shallows in the Zwarte Meer WF 20.* Shallows in the Veluwe Meer BE F. Roosts in flooded meadow areas Type: floods 21. FLOODS west o f BEETSTERZWAAG WF 22. f l o o d s near the grote brekken to the north of Ta :yl W F 23. f l o o d s in the haagse beemden WF BE 24. f l o o d s in the p u t t i n g , Zeeuws-Vlaanderen WFBE 25. flo ods on the gro ot-eilan d , Zeeuws-Vlaanderen WF BE G . Roosts in ‘closed estuaries’ Type: former tidal sands in static waters, closed from t sea as a part Project 26.* m iddelplaten in the Veerse Meer WFBE 27.* Shallows in the Braakmankreek WF H . Lakes and ‘vernieri Type : static fresh waters of some size ; ‘vennen’ are oligotrophic waters in the pleistocene 28. IDSEGASTERPOEL, province of Friesland PF BA 29.* Vennen near Duurswoude, east of Beetsterszwaag WF 30.* Vennen in the Kampina, province N. Brabant BE 31.* Vennen in the Strabrechtse Heide, N. Brabant BE J. Roosts on extensive frozen waters Type: any of the roosts mentioned above, most lakes in Friesland and 32. Ijsselmeer, west of the Noordoostpolder

General characters of the roosts Components (c) and (d) are closely The roosts in our list have some basic related, as tidal sandbars and extensive characters in common, (a) The geese want coastal shallows, where the geese can to be surrounded by an extensive area of stand on firm soil when roosting, are as a open waters, ice, sands or bare mudflat, rule free from all kinds of disturbance. where (b) vegetation is absent or at least Deeper waters, lakes and streams in the very low and thin; and (c) they want to be Netherlands are for the greater part undisturbed. integrated into the national transport A fourth component should be men­ system and therefore greatly disturbed by tioned here, as has been pointed out by all kinds of shipping, nocturnal fishing, etc. M ulder (in litt.). This is (d) the geese want It is with some doubt that component (d) to roost where firm soil is present. - the possibility for the geese to stand on The significance of these components firm soil - is mentioned, but it is striking may be the following: Component (a) : first that it is present in all types of roosts in our of all the geese want to be safe from list except in type H (lakes and ‘vennen’). predators and during the hours of darkness This suggests that the geese have a very they have to retreat to the most open type pronounced preference for roosts with firm of habitat. Completely open surroundings soil. The cause of this preference could be make it impossible for them to be approa­ that it allows them to stand or to lie ched unperceived. Component (b) may sleeping without sinking in the mud. They have the same significance. may stand sleeping with the water up to

GEESE IN THE NETHERLANDS 87 their bellies, but apparently they prefer not (.Phragmites). In static waters shallow to be afloat. In tidal waters, however, this places with firm soil are practically always may occur for a few hours before and after densely overgrown. high tide. Markgren (1963) describing the If the various types of roosts are com­ behaviour of Bean Geese A .f'.fabalis on pared, the following factors appear to be their roosts in southernmost Sweden says : responsible for their existence. ‘Particularly when geese sleep on the Those of group A, B and C are a result water, involuntary collisions must occur of the influence of the tide. In types D and comparatively often.. .The repeated contact E it is the size of the waters and their notes that are heard periodically from exposure to the southwestern winds which flocks lying on open water, are much rarer favour the presence of these shallows. The when the geese roost on ice’. These roosts of group F (floods) seem to be a observations suggest that the preference stable type. Grazing keeps the vegetation for a roost where the geese can stand or lie short during the summer. The turf, soaked on firm soil or on ice might also be due to though it may be, seems sufficiently firm the fact that it allows them to maintain for the geese to roost. In group G, the individual distance and prevents involun­ ‘closed’ estuaries, the roosts have what tary collisions. On the Swedish roosts might be called a ‘tidal past’ and this, no described by Markgren, the geese have no doubt, is responsible for their present state. opportunities to stand on shallows with Lake roosts of type H are a matter of wind firm soil in places where they are sur­ effect, but they are different from all other rounded by open waters of sufficient size. roosts, extensive open surroundings (factor There is detailed information on the a) being the only advantage they offer. roosting habits of the geese in Scotland and England (Boyd, 1963). Greylags have most Prospects for the future of their roosts on inland lakes, only a small We still have to study the prospects of the proportion roosting on estuaries. White­ various roosts, as their survival is not fronts in England roost on estuaries and beyond all doubt. Moreover a number of floodwaters, but there is an increasing use them will be affected by the Delta Project of large reservoirs as roosts. Bean Goose and the drainage schemes. roosts are all inland, on floodwater or hill 1. The factor tide which plays such an lochs. Pinkfoot roosts are about equally important role, will be eliminated by the distributed between the coast, nearly all Delta Project in the roosts of group B and in estuaries, and inland, mostly on lakes numbers 11-14 of group C, in which group but several on peat mosses. only roosts numbers 15 and 16 will remain All these data from S. Sweden, Scotland untouched. Where the tide is eliminated, and England suggest that the habit of the sand bars will either be too deep under roosting on firm soil, so pronounced in the water or they will be overgrown by rushes Netherlands, is not a general one. The and reeds. In some cases new roosts will conclusion may be that the wild geese have come into existence and it will be of great a strong preference for such roosts, though importance to manage such places by they may well do without it, but that in the grazing and mowing so as to prevent the Netherlands with its dense human popula­ development of vegetation. It is not impro­ tion, the presence of shallows is extra bable that the water level in these closed favourable as a safeguard against disturb­ estuaries will be lowered considerably ance. during winter, so that bare mudflat might All this does not apply to Brent Geese be available. These future roosts might be and to those Greylags living in extensive of the same type as those of group G. Our tidal areas, which follow a tidal cycle and experience of these roosts is very short, as do not roost at night. the Veerse Meer (No. 26) has been closed only since 1961 and the Braakman (No. 27) Ecological factors favouring the pre­ since 1952. In the former the water will be sence of roosts salt until 1978, which will prevent the The combination of the factors mentioned development of a high and dense vegeta­ under (a), (b) and (d) is not a probable one. tion. It is unlikely to occur except in very special 2. The main body of the Waddenzee conditions and even where the combination (group A) will remain tidal for some 30 to does occur at a given time, it is unlikely to 50 years and the wild geese will probably be permanent. On the contrary, it tends to find excellent roosting conditions here for be short-lived by nature, because shallow a long time. The present roosts in the places are either gradually eroded by the Waddenzee area, however, will be lost current or the effect of the waves or they within a few years. In the Lauwerszee a tend to be grown over by Cord Grass roost of type G might be possible, but all {Spartina sp.), Club-rush (Scirpus) or Reed shooting should be abolished there.

88 THE WILDFOWL TRUST 3. The roosts in the Ijsselmeer area have G r e yl ag G oose good prospects, though there seems to be In the Netherlands and in north-west a gradual increase of the vegetation. As the Germany (Harrison, 1952) Greylags have a size of the Ijsselmeer seems to play a part, distinct preference for the Scirpus-pioneer it should be mentioned here that in the vegetations of fresh and brackish estuaries. near future this size will decrease from In most localities pasture land is used as a some 200,000 ha to about 100,000 ha, which secondary habitat. On both banks of the may decrease the wind effect and con­ Hollands Diep estuary there is an increas­ sequently favour the increase of the ing preference for arable country, but vegetation. Our experience of roosts of Scirpus fields are still the major food stock type E is short, but they may survive for a here. Only in the province of Friesland and considerable time. in the State Reserve Boschplaat on the 4. Floods (group F) are considered to be Frisian Isle of Terschelling (Tanis, 1963) an anachronism in the Netherlands. The are Greylags feeding entirely on grasses. present co-operation between the owners This as well as the situation of the Grey­ of important parts of the roosts of No. 21 lags wintering in the British Isles (Boyd, and the State nature protection is therefore 1963) suggests that the species might well very welcome. Some purchases of land by survive on grasses only. the State in area 21 and others in areas 23 and 24 are also very important, though in Non-specialists the latter cases much has still to be done. Summarising the prospects we might W h it e -fronted G oose say that serious losses are to be expected Formerly typical for floods. Recently the in several regions. There will be a general majority has moved to areas within flight­ shift from tidal waters to static ones, where ing distance from coastal roosts. Here they both the abolishment of shooting and care­ may feed on dry pasture land in great ful management will be necessary. numbers for several months if undisturbed. This suggests that the floods have another III. The feeding grounds significance than food habitat only, their excellence as roosts being of primary Some species of wild geese are highly importance while they also provide good specialised in food habits, while others are protection against all types of disturbance. capable of adapting themselves to various types of human land use. In the case of the P in k -footed G oose latter, the ‘natural’ habitat selection may Since the ‘come-back’ of the species in be obscured and has to be ‘reconstructed’ the Netherlands in 1956 Pinkfeet have from incidental clues. been feeding entirely on pasture land in On the basis of experiences in the the southwest of the province of Friesland Netherlands (Lebret, 1964) the species in a region between the Ijsselmeer in the might be classified as follows. west and a number o f lakes in the south and east. In this way this region is well isolated Specialists and human disturbance is small. There B ren t G oose seems to be no ecological relation with Almost entirely a bird of the tidal zone of floods. A detailed description of the salt waters, feeding on Zostera, Enteromor- ecology of the Pink-footed Goose in this pha, Ulva and Puccinellia. In one case a area is given by den Daas {loc. cit.). group of some 130 birds was feeding in B ean G oose arable country on a grass-seed production In the Netherlands this species is to a field some 300 m. behind the sea wall for great extent using arable country, especially several months. on the modem farms with extensive fields, within flighting distance from the estuaries. Semi-specialists, with a preference for “natural” habitat but capable of Pasture land seems to be of secondary adaptation to agriculture importance. The species, therefore, might be classified as the one most adapted to B a rn acle G oose present-day farming. Timmerman (1962) thinks the specise From its ability to dig out waste potatoes to be specialising on saltings where and sugar beets, it may be supposed that brackish and fresh water are in regular the natural food of the species might to contact and where the plant communities some extent consist of tubers of Scirpus{an& of the Agropyro-Rumicion crispi predo­ other marsh plants. Indeed, some cases of minates. Philippona {in litt.) thinks that this feeding method are known (Lebret, the species may also thrive on the same I959)- Feeding on Cord Grass roots and habitats where White-fronted Geese have stems has been mentioned by Maebe and their main haunts. van der Vloet (1956).

GEESE IN THE NETHERLANDS 89 Prospects for the future all the tidal marshes with a pioneer-vegeta- After the feeding grounds of the various tion of Scirpus. This type of habitat will species of wild geese have been briefly disappear practically altogether in the described, we have to study the effect of Netherlands after 1968. Some 10,000 G rey­ the Delta Project and a number of other lags used to feed here. In the two IJssel- hydraulic engineering schemes. meerpolders still to be drained there may be a temporary revival of comparable 1. B rent G oose pioneer vegetation, but each of them will last only some 5-8 years, unless a special The main feeding grounds of this species reserve is created. This should be managed are found in the tidal marshes of the by extensive grazing during summer and Waddenzee, especially near the Isle of slightly flooding it in September-March. Terschelling. Some 3,000 birds may be If the Greylag Goose proves capable of found here (Tanis, 1963) and fortunately holding its own on pasture land - and there the area will remain untouched. The feed­ are several indications that it may do so - it ing grounds in the south west of the will be of the utmost importance that Netherlands will be lost after the Delta sufficient grazing opportunities are created Project has been completed in 1978, as the and maintained in nature reserves. There tide will be eliminated and the waters will are good prospects on the Bosplaat State become fresh. The number of Brents Reserve, where the numbers of Greylags are involved is not likely to exceed 500 birds. gradually building up and will have reach­ ed 1,000 birds. Rabbit shooting has been 2. B arn acle G oose abolished during the presence of the wild This species will lose practically all its geese in this reserve (Tanis, personal com­ present feeding grounds within the next munication). The Kwade Hoek and the 5-10 years. Its main haunt, the Bantpolder, Hompelvoet Reserves mentioned in refer­ harbours some 15,000 birds, but it will be ence to the Barnacle will be of positive value partly drained in 1965 or 1966. There is a for the Greylag Goose as well. The maxi­ possibility that a new feeding area may be mum numbers of the species occur in created in the Lauwerszee after this has October-November, when cattle are still been closed, in 1967, by sowing special in the fields, and March-April, when the pastures for the species and by managing grass is starting into growth, while the them as a sanctuary. There will, however, other species have their maximum in remain a gap of some 4-5 years between December-March. Hence the Greylags the loss of the Bantpolder and the possible may be in conflict with agricultural in­ effect of a sowing programme. In these terests. In October other human outdoor years the species might temporarily fall activities may be still in full swing at or back on the nearby Anjumer Kolken. It near their haunts. The birds may thus be would be advisable that all goose shooting more affected by human disturbance and should be temporarily forbidden there, as hence more dependent upon nature in this region the Barnacles, though fully reserves than are other species. Conse­ protected by law, are mixed with White­ quently they may have to feed in greater fronts and other geese and hence are liable concentrations and the carrying capacity to the disturbance caused by Whitefront of these Greylag reserves will need special shooting. The Barnacle feeding areas in the attention. southwest of the Netherlands (Dirklandse Sas and St. Anthoniegorzen) will be lost 4. W h ite- fronted G oose due to the Delta Project, which will be The feeding grounds of the White-fronted finished in this sector in 1969. Some 3,500- Goose will not be seriously affected by the 7,500 birds may now be feeding here Delta Project, but drainage and reallotment (Timmerman, 1962). These birds may find schemes further inland will do so. Partial a new haunt on the Kwade Hoek State compensation may result from a sowing Reserve. Moreover on the Hompelvoet programme which was started on the State Reserve, now a sandbank in the Middelplaten State Reserve in May 1964. Brouwershavense Gat estuary, goose pas­ This reserve has been created in the former tures may be created after this estuary has tidal zone of the Zandkreek, the first been closed in about 1970. Here again a estuary closed as part of the Delta Project. sowing programme would not be effective It is the first case where such a sowing until some 4 years after the closing of the programme has been brought into practice. estuary. On 4th January 1965 some 600 geese (Bean, White-fronts and Barnacles) ar­ 3. G r e yla g G oose rived, the numbers rapidly building up to This species will also be highly affected by well over 2000. On 13th January the flocks the results of the Delta Project. It will lose departed, after all the food had been

90 THE WILDFOWL TRUST consumed. Taking into account that the the roost should be managed in the present turf was still in its initial state of develop­ state; (c) in case jetcraft activities may be ment, the result seems encouraging. increased, flying under 750 m. should be We have found that drainage and reallot­ prohibited. ment schemes are affecting the wild geese especially by causing an increase of dis­ 6 . B e a n G o o s e turbance. Hence a possibility of compensa­ The prospects for the Bean Goose are tion for loss of feeding grounds may be relatively good. Large-sized arable fields found by the reduction of disturbance else­ cover wide areas within flighting distance where. This has proved to be successful in from the present roosts. The only un­ the case of the private reserve of Count favourable aspect is a strong tendency Lippens and others between the village of among farmers in the regions visited by the Damme and Bruges (Belgium), where all Beans to switch from the usual crops to goose shooting has been stopped since 1959 orchards and the acreage of the latter is and wild geese, especially Whitefronts, rapidly increasing. As far as can be fore­ have increased from a few hundreds to seen these developments are not likely to several thousands. The creation of this become a menace for the species. reserve came just in time to cope with the Generally speaking the non-specialists permanent loss of an important goose (Whitefront, Pinkfoot and Bean) and feeding area in the near vicinity in the probably also the Greylag and perhaps Netherlands (Suetens, 1961) even the Barnacle, could be helped greatly by reducing the disturbance caused by 5. P in k -footed G oose indiscriminate shooting. In this way a The prospects for the Pink-footed Goose considerable degree of tameness might area in Friesland have been discussed in develop in these species and this might detail by Den Daas (1963). His recom­ increase the number of areas accessible for mendations are the following: (a) total them. The readiness of a number of wild stop o f shooting at and near the roost on the fowlers to co-operate gives good prospects Idsegaster Poel (roost No. 28); (b) a feed­ for the future. ing area o f some 5 sq. km. within 3-10 km. of References ATKINSON-WILLES, G. L. 1961. Emsland without wildfowl. Wildfowl Trust 12th Ann. Rep.: 34-39. b o y d , H. 1963. The present status of the different species of wildfowl. Part III of Wildfowl in Britain, Monographs of the Nature Conservancy, Number Three. London. den daas, h. d. j. 1963. De Kleine Rietgans (Anser fabalis brachyrhynchus) als wintergast in Nederland. Report for the R.I.V.O.N. 107 pp. (duplicated). HARRISON, J. G. 1952. Estuary Saga: A wildfowler naturalist on the Elbe. Witherby, London. lebret, T. 1959- De afstand tussen voedselgebied en slaapplaats bij Ganzen, vnl. in Nederland. Limosa 32: 23-30. lebret, T. 1964. Oecologische successie en waterwildconcentraties. Ardea 52: 48-92. markgren, g. 1963. Studies on wild geese in southernmost Sweden, Part I: Migrating and wintering geese in southern Sweden, Ecology and Behaviour Studies. Acta Vertebratica 2(3): 299-418. MÖRZER bruijns, m. f. and j. t a n i s . 1955. De Rotganzen op Terschelling. Ardea 43: 261-71. MÖRZER bruijns, M. F. 1961. Bedreigd Waterwild. Natuur en Landschap 15: 14-19. PHILIPPONA, j. 1962. Ganzenpleisterplaatsen in Nederland: De omgeving van Beetsterzwaag en Gorredijk. Limosa 35: 17-28. PHILIPPONA, j. 1963. Voorkomen en terreinkeus van ganzen en andere vogels bij Lemmer. Vogeljaar 11: 114-118. s u e t e n s , w. 1961. Het ganzenreservaat te Damme. De Belgische Natuur en Vogelreservaten. Bulletin 1961. t a n i s . j. j. c. 1963. De vogels van Terschelling. Fryske Akademy, Leeuwarden. Timmerman, A. 1962. De Brandgans (Branta leucopsis) in Nederland. Limosa 3 5 :199-218.

GEESE IN THE NETHERLANDS 91 Spacing and chasing in breeding ducks FRANK McKINNEY

Summary The behaviour of breeding ducks is described in terms of the relationship of the pair to its home range and the responses of pairs to one another. There are specific, sex, and seasonal variations in the characteristics of the home range. Interactions between pairs involve five types of response : displays, attack, escape and avoidance, sexual pursuit, sociability. Chasing activities of paired males can be hostile or sexual in nature, the latter involving attempts to rape strange females. The characteristics of aerial pursuits (‘three-bird flights’ and ‘attempted rape flights’) of Anas species are believed to be determined by variations in the pursuing male’s tendencies to (a) stay with or near his mate, (6) attack other males, (c) rape strange females. Male hostility is associated with the existence of a strong pair-bond; raping is associated with a weak bond. A typical ‘three-bird flight’ results from conflict between the pursuing male’s tendency to chase the female of a strange pair (with intent to rape and/or possibly attack her) and his tendency to remain near his mate. Parts of the home range of each pair are shared with other pairs. Where a shared resource is localised in distribution, such as an island suitable for nesting, pairs tend to aggregate. Colonial nesting develops as a result of strong homing tendency in adult and young females, and high productivity in an area with light predation. The behaviour of a number of species appears to be adapted to the various types of resource-sharing required in different habitats. Chasing activities - both hostile and sexual in nature - are believed to bring about dispersion of various types. In a species with a small home range, a high level of hostility, and a strong pair­ bond (e.g. Shoveler), a pattern close to classical ‘territorialism’ is apparent. In more mobile species, there is much overlapping of ranges and the degree of dispersion of pairs (and resulting dispersion of nests) can vary considerably with local conditions. The primary function of chasing and the spacing resulting from it is thought to be the dis­ persion of nests as an anti-predator mechanism. introduction Hochbaum applied to ducks the theory Ducks are primarily social birds but during of territory propounded in detail by at least part of the breeding season pairs of Howard (1907-14,1920) and subsequently many species show a tendency to spread developed by other ornithologists, espe­ out over the nesting habitat. Chasing cially Lack (1939), Nice (1943) and Tin­ behaviour often coincides with the break­ bergen (.1939). ‘Territory’ was defined, in up of flocks and the period during which the same way as it is today, as ‘a defended pairs are dispersed. The occurrence of both area’. Hochbaum contended that each spacing and chasing is well established for paired male defends a certain stretch of many species, but the survival value of water against intrusion by other sexually these phenomena and the behavioural active birds of the same species, the main mechanisms involved are still uncertain. function of this behaviour being to prevent In 1924, Geyr von Schweppenburg interruption to the pair ‘during the copula­ suggested that certain aerial chases of the tion link of the reproductive cycle’. M allard Anas platyrhynchos, described Hochbaum believed that ‘the nesting originally by Heinroth (1911), represent population of any breeding marsh is attempts by a paired male to drive off other determined by the territorial distribution pairs from the nesting area. He believed o f pairs’. that such behaviour helps to preserve an Subsequent research by Sowls (1955) exclusive breeding area for each pair, and Dzubin (1955), on individually marked ensuring an adequate food supply for the birds, showed that Hochbaum’s original young. Although Geyr’s interpretation of conception of territory was too rigid. There Mallard pursuit flights has been questioned are not always ‘definite boundaries to by several authors, and his paper provided defended areas’ and the home ranges of the stimulus for a long controversy on all neighbouring pairs often overlap. Recent types of aerial behaviour, the idea that studies by Lebret (1961) and Hori (1963) ducks are territorial has come to be widely on the Mallard have indicated that aerial accepted. This is particularly true in North pursuits, of the type called ‘territorial America where the territory concept defense flights’ by Hochbaum, sometimes provides the basis for ‘the breeding pair occur away from the nesting grounds. As a count’ method of censusing populations. result of this discovery, Lebret has sug­ The major credit for development of the gested that the term ‘territory’ should not theory of duck territory must go to Hoch- be applied to the Mallard, while Hori baum (1944), who stressed the importance believes that neither the Mallard nor the of the phenomenon in the species breeding Shoveler Anas clypeata holds territory. on the Delta Marsh in southern Manitoba. Bezzel (1959) has also criticised Hoch-

92 THE WILDFOWL TRUST baum’s theory, concluding that ‘the tion’, however, there are seasonal changes territory plays a small part in the structure in the relationship of each duck to the area of a breeding population’. Gates (1962) it occupies, and there are also important believes that in the Gadwall Anas streperà differences between the ranges of males and territorial behaviour was ineffective in females. In some species, the places visited limiting the number of pairs nesting on his by each bird probably change to some study area in Utah. extent from day to day, and many factors These findings appear to cast consider­ influence the location, size, and perman­ able doubt on the validity of the concept of ence of the various ‘ranges’ occupied duck territoriality. In fact, however, the successively by each individual. An under­ main criticisms have been directed at (a) standing of these changing relationships the use of the word ‘territory5 where between the members of the pair and the evidence for a defended area is not obvious, areas they occupy is fundamental to the and (b) the idea that behaviour involved in study of pair-spacing. Unfortunately, only the defence of an area has an important a few studies of marked birds have been effect on the density of breeding popula­ made, and surprisingly little is known about tions. Thus much attention has been given the daily movements of individual ducks to inquiring whether and how ducks during the breeding season. ‘defend areas’ and how chasing behaviour (especially aeriai pursuit) is related to such Homing areas. The broader biological problems of Tendencies for adult females to return to pair-spacing - the pattern of pair distribu­ breed in the same area in successive years tion on the breeding grounds, the mecha­ and for young females to breed close to the nisms by which this is achieved, and the area in which they grew up have been survival value of the different patterns demonstrated for a number of species and found in different species - have received are probably general in ducks. In hole- less emphasis. nesting species such as the Goldeneye As Tinbergen (1957) has stressed, it is Bucephaia clangula (Siren, 1957), Buffle­ important to distinguish between the com­ head Bucephaia albeola (Erskine, 1961), ponents of what we call ‘territorial beha­ W ood D uck A ix sponsa (Bellrose, John­ viour’. In most birds these appear to be son and Meyers, 1964), and Shelduck (a) attachment to a site and (b) hostility, Tadorna tadorna (Hori, 1964) some two distinct forms of behaviour which, females have been shown to use die same when they occur simultaneously, give the site in successive years. Mendall ^1958) impression of ‘defence of an area’. It believes that Ring-necked Ducks Aythya seems best to avoid ‘a purely speculative collaris will also do this but, as Bellrose assumption that the area carries special et al. (loc. cit.) have shown for the Wood significance to the bird as an object to be Duck, an unsuccessful nesting attempt defended’ (Emien, 1957). may cause a bird to choose a different site In this paper, I will discuss the factors the following year. The Eider Somateria which appear to be involved in pair-spacing mollissima also shows faithfulness to the in those species of duck which have been nest-site (Gudmundsson, 1932; Cooch, studied in some detail. I have avoided the 1957) but other ground-nesters select new words ‘territory’ and ‘defence’ except in sites each year (Koskimies and Routamo, referring to the ideas of other workers. In 19535 Sowls, 1955). this way, I hope to concentrate attention In most migrant ducks, precise homing on ‘doings and happenings rather than by males is thought to be a rare event, but objects and entities’ (Emien, 1957). there is little direct evidence since few males are banded on the breeding grounds. The pair and its home range Most pairs are formed on the wintering During the main part of the breeding grounds or during spring migration, the season - egg-laying, incubation, and bonds being broken again when the male rearing of the brood - female ducks must leaves his mate in the middle of the breed­ restrict their movements to an area quite ing season. (It is possible that some pair­ close to the nest-site. For at least part of bonds remain intact through the summer this period, the male occupies approxi­ when a female loses her clutch and does mately the same region. Sowls (1955) not attempt to re-nest, but this has not called this area the ‘home range’, a term been proved with marked individuals). previously applied to mammals, defining it Thus unless the members of the pair meet as ‘the area within which a bird spends its again on the wintering grounds or at some period of isolation between the break-up stopping place on migration they must of spring gregariousness following spring form a new pair-bond each year. Many arrival and the reformation of fall grega­ birds from a particular section of the riousness’. During this ‘period of isola­ breeding range tend to follow similar

BREEDING BEHAVIOUR 93 migration routes and winter in approxi­ and also in accordance with variations in mately the same areas, but nothing is weather and habitat conditions. The known of the frequency with which mates Mallard and Pintail are early spring reunite. No doubt there is much variation migrants and early nesters, and in southern between species and between populations. Manitoba laying normally begins soon after Some re-pairing of the same individuals the break-up of migrant flocks (Hochbaum, occurred in a resident population of 1944; Sowls, 1955). In the Gadwall, how­ .Mallards (Weidmann, 1956). In a captive ever, Gates (1962) found that an interval of flock of Shovelers, some birds re-paired a month may elapse between the arrival of while others deliberately chose new mates residents and the laying of the first eggs. (McKinney, in prep.). Erskine (1961) has There is little information on the move­ shown that male Buffleheads tend to return ments of pairs during this pre-nesting to the same wintering areas in successive period. In many species, it is difficult to winters, and if their mates are faithful also distinguish returning residents from mig­ to these places, pair-bonds could be rants on passage. Limited observations on renewed. On present evidence, however, it marked Canvasbacks Aythya vallisneria is likely that most ducks change mates by Dzubin (1955) and on Gadwall by Gates annually, females returning to a familiar (1962) suggest that pairs are more mobile home range, males following their mates to during the period before nesting than after an unfamiliar breeding area each year. breeding begins. Sea Ducks (Mergini) do not breed in Pairs assumed to be involved in selecting their first year, but sub-adults are seen on a home range or a nest-site are seen making the breeding grounds and presumably flights over the nesting terrain. Hochbaum, youngbirds gain valuable experience during (1944) saw ‘nuptial flights’ performed by their period of maturation. In Anatini,young pairs of all species of Anas and Aythya that birds do breed in their first spring, but he studied, and it seems likely that these they have several disadvantages. In plum­ are, at least in part, reconnaissance flights. age development and time of pairing, Sowls U 955) noted Mallard and Pintail young Shovelers lag some weeks behind pairs making evening flights over nesting adults, and they tend to be less successful cover a few days before egg-laying began. in competitive pairing situations (McKin­ Mendall (1958) suggests that aerial recon­ ney, in prep.). In the Pintail Anas acuta naissance by Ring-necked Duck pairs (Sowls, 1955) and Gadwall (Gates, 1962), occurs mainly during the period between adult females return early to their breeding arrival and the beginning of nest-site home ranges, young birds arriving later. selection, which may be as long as two Under crowded conditions, late arrivals weeks. Smith (1963) describes ‘explora­ may have to move some distance from the tory flights’ in Pintail pairs, and similar area with which they are most familiar. manoeuvres occur in the Velvet Scoter Thus experienced, adult ducks probably Melanitta fusca (Koskimies and Routamo, have ‘first choice’ of mates and of home 1953) and Common Eider (Cooch, 1957; ranges, and in general adult females will McKinney, 1961). have the greatest familiarity with the In species which nest some distance breeding home range. from water, parts of the habitat suitable When breeding habitat deteriorates or for the nest-site are presumably selected disappears, homing traditions are broken during these reconnaissance flights. The and pairs must establish new home ranges. final selection of the site is made on foot This is a rare event in Eiders, colonies in the case of ground-nesters, by swimming remaining on the same islands for centuries, in species using emergent vegetation, and but it is a common phenomenon in species by flying from tree to tree in the case of dependent on water areas in regions which hole-nesters (see descriptions in Hoch­ fluctuate between conditions of drouth and baum, 1944; Mendall, 1958; Leopold, flood. The drying-up of a pothole may 1951). In all species studied to date, the cause a pair to move only a few hundred male accompanies the female during her yards, but widespread drouth on the exploration of potential nest-sites. I have North American prairies or over wide found no precise information on the area areas in Australia can cause massive move­ covered by a pair of any duck species ments of breeding populations (Frith, during this period of pre-nesting flights. 1959). Nest-construction and laying The pre-nesting period and nest-site In the Canvasback (Hochbaum, 1944), selection Redhead Aythya americana (Low, 1945), The interval between arrival in the general Blue-winged Teal Anas discors (Glover, vicinity of the breeding area and the 1956)3 and other Anas species (Sowls, beginning of nesting varies between species 1955) nest-construction may begin several

94 THE WILDFOWL TROST days to a week before laying starts. Infor­ Break-up of the pair mation is scanty, however, and it is quite Dzubin (.1955) found that the drake possible that some individuals select the Mallard’s range increases once his mate site, scrape the nest-bowl, and lay the first has begun to incubate and he gradually egg, all on the same day. Eggs are usually spends less and less time at the waiting laid in the morning hours, the male areas. So the members of the pair meet remaining in the vicinity while the female less often, and the pair-bond appears to is at the nest. At this stage, the pair-bond become progressively weaker until it is is still very strong and Hochbaum (1944) finally broken when the male moves away. noted that males may have special waiting The break-up may be more abrupt in other places close to the nest. species, but there is little precise informa­ Dzubin (1955) found considerable spe­ tion on this point. cific differences in the ranges occupied by The stage of the breeding cycle at which Canvasback, Mallard, and Blue-winged the male breaks off contact with his mate Teal pairs during the pre-nesting and varies between species (Table I), and there laying phases, the Canvasback being most are also considerable individual variations mobile, the Teal least. (.e.g. Stotts and Davis, i960). In most Range during incubation species, the male leaves at some stage during incubation. During late nestings or Once the female begins to incubate, the re-nesting attempts, the male leaves earlier male sees her only for short periods when than in the case of early nests. she leaves the nest. Most species have one Striking effects of the chronology of the or two such periods each day, when the breeding season have been noted by Alex female feeds, bathes and preens, ijncubat- Dzubin (in litt.). He reports that in the ing Eiders do not feed; the female leaves early mild spring of 1958 in southern the nest only briefly at 2 or 3-day intervals, Saskatchewan, when Mallard broods began to drink). Especially during morning and to appear by 15th May, he recorded 15-20 evening hours, males spend much of their cases of males accompanying broods; in time on certain water areas - ‘waiting most years, when hatching peaked after areas’ (Dzubin, 1955), where dry-land 25th May, only 1-3 records were obtained. ‘loafing spots’ (Hochbaum, 1944) are used Since most ducks will re-nest if the first by many species. It is to one of these places clutch is lost, the stage at which the male that the female flies when she comes off the deserts his mate may have an important nest. If the male is there, the two birds effect on the female’s behaviour between remain together until the female returns nesting attempts. If the male has left, as to the nest. The pair-bond remains intact must often be the case in species where the only as long as the male frequents these bond breaks early, the female must either areas. find a new mate or be fertilized by a male Females seem to travel no farther than other than her mate. Re-pairing with a new is necessary when they leave the nest. mate has been recorded for Gadwall (Gates, Ground-nesters often fly to the nearest 1962) and Pintail (Smith, 1963). In species water, and this is where many male such as the Shoveler, in which the male ‘waiting areas’ are situated. There are remains until late in incubation, the original variations in the distances involved, some pair-bond is probably maintained through species such as the Pintail nesting much all nesting attempts. farther from water than others. The distance between nesting cover and feeding grounds also varies with local conditions Range of the female and brood (Bezzel, 1959; Gates, 1962). After the ducklings leave the nest, the There are specific differences in the factors controlling the female’s mobility mobility of paired males during the incu­ change. She is no longer tied to the nest- bation period. In Manitoba pothole site and its immediate surroundings, but country, Dzubin (1955) found that drakes as she leads her brood her movements are of Canvasback, Mallard, Pintail, and Red­ now restricted to ground and water sur­ head ranged widely during the incubation faces. In some cases, the areas frequented period but Blue-winged Teal did not. At by the female and brood are close by the Ogden Bay, Utah, Smith (1955) and Gates nest site. Mendall (1958) noted that some (1962) noted that Mallard ranged most Ring-necked Duck families spent the widely, Cinnamon Teal Anas cyanoptera entire rearing period within an area a few and Shoveler least, while Gadwalls were hundred yards long, provided adequate intermediate in range. In Maine, Mendall food and cover were available and there was (1958) found that Ring-necked Ducks have no disturbance. Other Ring-necks, which a much smaller range than Black Ducks nested on small marshes, had to lead their Anas rubripes. ducklings a mile or more to suitable habitat.

BREEDING BEHAVIOUR 95 Table I. The stage of the breeding cycle at which the pair-bond breaks.

First Last week of Mid- week of After Species incubation incubation incubation hatching

Anas acuta X 3»6»13 A?ias platyrhynchos X 3»6»3»13 X2 Rare2 Rare15 Anas rubripes early nests : X 6»13 X 4 X 4 late nests : X 14 X 14 Anas streperà early nests : X 4 Rare4 late nests : X 4 Anas discors X 2 Rare2»3»6»13 Anas cyanoptera X 12 Anas clypeata X 5,6,10,12,13 Once12 Aythya vallisneria X 6 X 2 Aythya americana X 6 Once® Aythya collaris early nests : X 11 late nests : X“ Aythya ajfinis X e Aix sponsa early nests : X 1 X 9 late nests : X 9 Melanitta fusca X 7 Oxyura jamaicensis X 6

> Hoch- banm, 1944; 7 Koskimies and Routamo, 1953; 8 Lebret, 1961; 9 L< unpublished; 11 Mendall, 1958; 12 Smith, 1955; 13 Sowls, 1955; 15 Dzubin (in litt.).

On pothole nesting terrain, where many newly-hatched Mallard broods moving 3 water areas of different types are located miles and 3 J miles in two days. close together, families regularly make overland crossings of several hundred Exclusiveness of the home range yards. Evans, Hawkins and Marshall (1952) Except in the case of very isolated pairs, reported specific differences in the mobility home ranges are shared to varying degrees of broods on the Minnedosa pothole with other members of the same species. country of Manitoba : Pintails moved most, The greatest overlap is probably found in Ruddy Ducks Oxyura jamaicensis did not the colonial-nesting Eiders, in which areas move, while other species of Anas and used for feeding, resting, nesting, and Aythya moved varying distances during brood-rearing are occupied by many birds the course of the brood period. at the same time. Most species of ducks In some species, spectacular travels are freely share brood-rearing areas. In some undertaken by very young ducklings. species, such as the Gadwall (Hammond Leopold (1951) observed newly-hatched and Mann, 1956) and Black Duck (Stotts Wood Ducks being led across the Missis­ and Davis, i960) nesting concentrations sippi River to secluded feeding areas. are found on islands, and in these situations Allowing for the current, the families had there is much overlap. In Aythya species, to swim a distance of about three-quarters such as the Canvasback (Dzubin, 1955) and of a mile, and they accomplished the trip Ring-necked Duck (Mendall, 1958), several in about 20 minutes. The Eiders of the paired males may share the same waiting Inner Farne lead their young ducklings areas while their mates are incubating. across i-J miles of open sea to the mainland Among the Anas species which have been coast of Northumberland, where they studied, the home ranges of Shoveler pairs spend the rearing period. Black Duck probably overlap the least, as a result of the energetic chasing activities of paired males broods hatched on Ile aux Pommes, (see pp. 93-4). Even favoured loafing spots Quebec make a crossing of 3I miles to the may be shared by pairs of Gadwall, Mallard mainland shore of the St. Lawrence and Blue-winged Teal, being occupied by immediately after leaving the nest (Reed, different pairs at different times (Sowls, 1964). Dzubin (in litt.) has records of 1955; Dzubin, 1955; Gates, 1962).

96 THE WILDFOWL TRUST The behaviour of the pair in relation dica, males threatening and chasing a to other birds variety of other species (Myres, 1957; Social responses appear to play an import­ personal observation). Generalised aggres­ ant role in determining patterns of pair- siveness toward other birds is also shown spacing. In attempting to understand the by some incubating ducks and by females pattern found in each species, it is parti­ with broods, but only when they are cularly important to know how pairs approached closely. behave when they encounter other birds, The role of ‘avoidance’, in the sense of how the behaviour varies with the stage of an active search for isolation from other the breeding cycle, and how the encounters birds, is very difficult to assess. Mendall are related to the components of the home (1958) has observed pair-spacing in the range occupied by the pair. Ring-necked Duck without obvious hosti­ lity, but the possibility should not be ruled Types of response out that this results merely from ‘retreat Five types of response can be distinguished without being involved in a hostile encoun­ when pairs come in contact with other ter’. Avoidance of this type may well be a ducks: (a) visible and/or audible displays, common phenomenon in many species. It (b) attack, (c) escape and avoidance, (d) is possible to find an ‘isolated pair’ of a sexual pursuit and/or rape, (e) sociability. certain species, and breeding populations There is strong circumstantial evidence may be so thinly distributed that pairs that certain displays of paired males are seldom encounter other members of the expressions of hostile tendencies and that same species. But the factors responsible they have threat function. Hochbaum for such situations are unknown. In some (1944) noted the association of the male years, only a few Green-winged Teal Anas Canvasbacks ‘Sneak’ with hostility. Simi­ crecca carolinensis breed on an area of the lar postures, with the neck stretched for­ Delta Marsh occupied by hundreds of ward over the water, are seen in male Blue-winged Teal pairs. This pattern of Goldeneyes and Buffleheads immediately distribution could result from precise before an underwater attack. Hostile homing by a few females during a period Pumping in the Blue-winged Teal and of low population numbers, rather than a Shoveler is closely linked with aggression. deliberate attempt by these pairs to isolate The threat function of these displays is themselves. indicated by the observed avoidance Aggressive behaviour is identified on the responses in other birds. No doubt other basis of the movements involved and the species have similar displays, but although result of the encounter. Rushes across the there may be evidence that the performing water or aerial pursuits involving two bird has a tendency to attack, threat males, or intention movements of advanc­ function is often more difficult to prove ing performed by a female toward a strange e.g. ‘Rab-rab’ palaver of the Mallard male clearly fall into this category. Similar (Weidmann, 1956), Cooing-movements of activities performed by a paired male and the Eider (McKinney, 1961). directed toward a strange female present a Overt attack and escape are commonly different problem. Some of these chases observed in paired ducks. Attack behaviour end in rape of the strange female. I have patterns vary greatly in intensity and dura­ records of rape in the Mallard, Pintail, tion, from momentary intention move­ Gadwall, Shoveler, Blue-winged Teal, ments to prolonged pursuits. Chasing can Cinnamon T eal and Baldpate Anas occur on land, over the surface of the americana. Very often, however, these water, underwater, and in the air, but there chases end inconclusively; the male chases are variations from species to species. In for some distance and then gives up. In certain highly aquatic species (e.g. Aythya other species, in which rape has not been species, Ruddy Duck) showing a relatively recorded (e.g. Lesser Scaup Aythya low level of aggressiveness, encounters affinis), paired males make rushes toward generally involve at most a rush across the strange pairs on the water, directing their surface of the water. At higher intensities, attention to the female. In these cases, it is a short attack flight can occur, and in the very difficult to determine whether the Shoveler vigorous aerial pursuits are seen. male’s intention is rape, attack, or a com­ Underwater attacks are performed by ag­ bination of the two. Some authors (e.g. gressive male Goldeneyes and Red-breasted Weidmann, 1956; Bezzel, 1959) believe Mergansers Mergus senator. The response that all such chases in the Mallard are to an attack is usually retreat by the other sexually motivated; Lebret (1961) believes bird, but occasionally this does not occur that some chases ‘have no other source and fighting ensues. than intolerance’ while others are the Inter-specific hostility is rare. It occurs result of an attempt to rape (see pp. 93-4). in Barrow’s Goldeneye Bucephaia islan­ In most species, pairs are sociable during

BREEDING BEHAVIOUR 97 spring migration and immediately after was impressed by the absence of friction arrival on the breeding grounds. Flocks in migrant flocks of Mallard, Pintail, and break up when pairs begin to establish Lesser Scaup pairs at Delta. This could their home ranges. At the same time, reflect true specific differences, but tempo­ aggressive or sexual chasing appears in rarily reduced hostility might also be many species, and these activities clearly expected in tired migrants and in response conflict with sociability. The balance to cold weather. A cold snap in early spring between these opposing tendencies - to brings aerial chasing to a halt in Mallards, associate with other birds and to chase when pairs are forced to congregate on them - is different in various species. At small open-water areas (Dzubin, in litt.). one extreme, Eiders remain sociable even Lebret (1961) has observed chases by a during the selection of nest-sites, pairs paired male directed at the female of an­ walking about close together with only other pair in European Teal Anas crecca mild indications of hostility. Male Shove­ crecca and Pintail during spring migration, lers, on the other hand, remain intolerant before the birds had reached their breed­ of the approach of other Shovelers until ing grounds. These chases had the same late in the incubation period. Dzubin (1955) appearance as Hochbaum’s ‘territorial de­ noted one form of ‘compromise’ in Blue­ fense flights’ (.see p. 93). winged Teal pairs which he believed were distributed in ‘communities’; although Responses of the pair on the breeding hostile encounters were frequent, the strife grounds did not seem to discourage community (a) Behaviour toward unpaired males. gatherings. In most species of Anas and Paired males continue to show hostility Aythya, paired males begin to associate in toward unpaired males after arrival on the groups, for parts of the day at least, soon breeding grounds, and in general this after incubation begins. response seems to persist as long as the pair-bond remains intact. Again there are Responses on the wintering grounds specific and individual variations which and during spring migration have not been studied in detail. Sometimes In many species, it is known that aggres­ a lone male is tolerated close to a pair. sive behaviour accompanies the process of Hochbaum (1944: p. 70) distinguished two pair-formation which takes place several types of unmated males, those which are weeks or even months before the breeding ‘sexually active’ and those which are not season begins. Males are aggressive toward (‘novice drakes’), and he believed that the other males, and females threaten males latter are tolerated while the former are which they are rejecting. These responses driven off by paired males. There have continue after the pair-bond is formed, been no studies of marked birds and this both male and female malting threat move­ point needs further investigation. ments or chasing unpaired males which (b) Behaviour toward other pairs. Most show an interest in the female. The details studies of interactions between breeding vary from species to species, but the pairs have been made on Anas species, and pattern is basically the same in all ducks almost all attention has been concentrated that I have watched. Such behaviour is on the aerial pursuits which are so striking usually referred to as ‘defense of the mate’ in this group. These are discussed below, or ‘mated female distance’ (Koskimies but I will first refer to the characteristics and Routamo, 1953). of encounters on the water which are Hostility between pairs can also occur important in many species. both on the wintering grounds and during In spite of their strongly social habits, spring migration. This was a common Eider pairs engage in frequent mildly reaction between pairs of Blue-winged hostile encounters: both sexes give dis­ Teal and Shoveler that I watched in plays, make threatening movements, and Louisiana in March, before the birds males in particular peck at males of other started on their northward migration. I pairs when groups of pairs come close have seen similar behaviour among newly- together on land or on the water. In the arrived pairs of Shovelers and Canvasbacks Canvasback and Lesser Scaup, similar at Delta in late April. I have also seen encounters occur between swimming pairs, intense hostility among Common Golden­ but in most cases males seem to direct eyes as early as mid-April in Manitoba, their attention to the female of another males driving other birds away from pair. These chases seldom involve more stretches of ice-free water to which they than short rushes across the surface of the were temporarily confining their activities. water and chasing males rarely take to the (I do not know if these birds stayed to air. Aerial pursuits appear to be absent also breed nearby, but I suspect that they did in the European Pochard Aythya ferina not). In contrast, Hochbaum (1944: p. 43) and Tufted Duck Aythya fuligula (Bezzel,

98 THE WILDFOWL TRUST 1959)- In the Ring-necked Duck, Mendall phases), paired males are observed in four (1958) noted very little aggression between basic types o f ‘social’ activities : (a) accom­ pairs; it was apparent only in crowded panying the mate (or remaining nearby habitats and was confined to the period of while she is at the nest), (b) behaving nest-site selection. Hostile encounters aggressively toward other birds (males in between pairs are frequent and often particular), (c) pursuing females other than energetic in Barrow’s Goldeneye (Munro, the mate, and (d) associating peacefully 1939), Bufflehead ^Munro, 1942), and with other males. The amount of time spent American Goldeneye (personal observa­ in each of these activities varies between tion). In these species, males direct their species and also with different stages of the threat postures and underwater attacks mate’s breeding cycle. In wild populations, toward other males ; at times they will take of course, the situation is enormously wing, flying short distances to attack. complex as a result of individual variation In the Shoveler and Blue-winged Teal, in the timing of the reproductive cycle and paired males on their home ranges usually the procedure of re-nesting after the loss react to the appearance of swimming birds o f a clutch (in some cases with a new mate). of the same species (pairs, solitary males or The need for a complete knowledge of the females) by giving Hostile Pumping, swim­ ‘history’ of the individual birds under ming toward the intruder(s), and if neces­ observation is obvious. sary by chasing with a rush across the water A comparison of paired-male behaviour or an aerial pursuit. When two well- in the Pintail, Mallard, and Shoveler matched males meet on the water and (Table II) suggests that specific variations neither retreats, spectacular fights occur, in tendencies to stay with or near the mate, the birds thrashing around one another to attack other males, to associate with with circular manoeuvres. other males, and to rape strange females The most obvious feature of encounters can account for many of the different between pairs in many Anas species are the characteristics of pursuit flights in the three aerial pursuits. Most observers have species. distinguished two types: In the Pintail, Smith (1963) found that (i) three-bird flights involve pursuit of the paired males are not aggressive to one female of a pair by a paired male, the another, and many can use the same water female’s mate being the third bird in the areas without friction. They frequently group. The chases are often brief, the leave the mate to pursue and attempt to pursuing male returning to his starting rape strange females. Many of these pur­ point after flying a short distance. This suits are energetic and prolonged, the birds descriptive term was first used as an adap­ covering great distances. The sight of such tation of ‘three-bird chase’ (Dzubin, a flight stimulates other males to join in. 1957) at the 1958 Delta Seminar, and it Thus three-bird flights frequently develop has since been adopted by Hori (1963). into attempted rape flights and Smith These flights have been called ‘Vertrei­ could not draw a sharp distinction between ben’ by Geyr (1924), ‘territorial defense the two. Many flights proceed to a great flights’ by Hochbaum (1944), and ‘expul­ height and come to an end when the female sion flights’ by Lebret (1961). makes a spectacular dive toward the (ii) attempted rape flights (1957 Delta ground. Males are most active in chasing Seminar; Lebret, 1961) are prolonged, strange females at the same stage of the vigorous chases, involving the pursuit of a breeding cycle when their mates are being female by a number of males. These flights chased, i.e. the period just before and often range far from the original starting during egg-laying. place and they have been observed to end In the Mallard, paired males do show in promiscuous rape of the female, after overt aggression toward other males she was forced to the ground. (Dzubin, 1955; Gates and Beer, 1956; The distinction between these flights, Lebret, 1961), although such behaviour is their relationship to other aerial behaviour considered rare by Dzubin, and it was not patterns, and the motivation of the pur­ recorded by Hori (1963). The distinction suing male(s), have been subjects of argu­ between three-bird flights and attempted ment for many years and there are still rape flights is clearer in this species: conflicting opinions (for references see immediately before and during laying most Geyr, 1961; Lebret, 1961). Recent studies pursuits are brief, they cover a small area, on the Pintail (Smith, 1963) and Shoveler and the pursuing male generally returns to (McKinney, in preparation) suggest that a his starting point after flying a distance of comparative approach may be helpful in up to half a mile (Dzubin, 1957). Males elucidating these problems. begin to associate in groups during parts of During the period when aerial chases the day early in the incubation period, occur (pre-laying, laying, and incubation although the pair-bond may still be intact.

BREEDING BEHAVIOUR 99 Attempted rape flights are common, once intolerance around the breeding pair which incubation has begun, and Lebret (1961) moves as the pair moves’. believes that they are associated especially In the Blue-winged Teal, Dzubin (loc. with the time when the pair-bond is cit.) noted that males are aggressive toward breaking. They have not been recorded other birds in the absence of the mate, but reaching the great heights that they do in ‘the presence of the female increases the the Pintail. In general, Mallard pursuits male’s aggressiveness’. I have noted the are less prolonged and cover less ground same phenomenon in a male Shoveler; than those of the Pintail. after his mate’s clutch was removed and In the Shoveler, paired males are hostile she began to spend all her time with him toward other males and vigorous pursuits during the ‘re-nest interval’, the male occur as long as the pair-bond remains showed increased hostility, apparently as a intact, which is usually late in incubation. response to the female’s presence. Gates Females of strange pairs are also pursued (1962) observed that ‘territorial chasing’ but, at least while the pair-bond is strong, (= three-bird flights) in the Gadwall rape is rare. Three-bird flights are com­ ‘normally occurred only when the pair was mon, the pursuing male centring atten­ together’, and he concluded that this type tion on the strange female, but her mate of chasing ‘appeared to represent the often threatens and pecks toward him in defense of the mated hen rather than flight. These pursuits are typically short, defense of the nesting area’. the chasing male returning quickly to his Many paired males also behave aggres­ starting point. sively while the mate is on the nest, but The behaviour of some other Anatini there need be no fundamental difference in seems to fit fairly closely to each of these the cause of the hostility. These males know three types, although the evidence is even where the nest is situated and intense less complete and each species will have to hostility in the vicinity of the nest, as be studied very carefully. The Green­ recorded in male Canvasback and Blue­ winged Teal is similar to the Pintail in that winged Teal by Dzubin (1955), is probably paired males frequently leave their mates related primarily to the female’s presence to join in energetic attempted rape flights. there. Thus the aggressive responses of The Blue-winged Teal and Cinnamon paired males on the breeding grounds are Teal, on the other hand, show their close basically similar to those shown by males phylogenetic relationship to the Shoveler during pair-formation, and by paired males by their strong development of aggression on the wintering grounds and during spring between males, long-lasting pair-bonds, migration. There may be threshold differ­ and typically short pursuit flights. The ences, but I suggest that the restriction of distinction between three-bird flights and the male’s responses to a certain area is attempted rape flights is apparently as clear primarily a result of the female’s attach­ in the Gadwall (Gates, 1962) as in the ment to the area she selects for breeding ivlallard, but in the former overt hostility and subsequently her attachment to the between males is frequent in flight. nest. A male Shoveler can be found day after The motivation of chasing behaviour day on the same small pothole, spending In general, aggressive behaviour in paired much time resting on a certain log. But males is associated with the presence of a when this bird pursues a passing male or strong pair-bond. This is illustrated well pair there is no need to suppose that he is by the relationship of male aggressiveness ‘defending’ either the water area or the to the presence and location of the mate. log. The approximate location of ‘waiting In the Velvet Scoter, Koskimies and areas’ is determined by the position of the Routamo (1953) described an area around mate’s nest; their precise location, by the the pair which is defended by the male and habitat preferences of the species and the moves with the pair. Dzubin (1955) des­ individual’s relationship with other birds. cribed a ‘moving territory’ in the Can­ If conditions are favourable, the waiting vasback - an area around the female, about areas are on the nearest piece of water six feet in diameter, in which the male is (Dzubin, 1955; Stotts and Davis, i960), aggressive toward other birds : paired males but in other cases they must be further rest peacefully together while their females away to satisfy the requirements of the are at the nest, but as soon as one male is waiting male. Thus the use of ‘loafing joined by his mate he becomes aggressive. spots’, ‘waiting areas’, or ‘territories’ (in Similar behaviour was recorded by Men­ Hochbaum’s sense) is dependent on the dall (1958) in the Ring-necked Duck. As a existence of the pair-bond, and I believe result of studies on Mallard, Gadwall, that hostility of males using them regularly Shoveler, and Cinnamon Teal, Smith is primarily an expression of the male’s (1955) concluded that there is ‘an area of attachment to his mate.

100 THE WILDFOWL TRUST Participation in attempted rape flights is tendencies conflict with the sociability of characteristic of males with a weakening males and with the male’s attachment to his pair-bond. In the Mallard and Gadwall, mate, respectively. Thus while I agree with attempted rape flights are seen once incu­ the general belief that many pursuits are bation has begun when paired males are motivated primarily by ‘sexual tendency’, showing less attachment to the mate and to it should be stressed that this is specifically the waiting area near the nest. In the a ‘rape tendency’ which is in conflict with Pintail, this behaviour appears even earlier the pursuer’s ‘tendency to remain with or (before and during laying), but in this near the mate’. I cannot agree with the species the pair-bond is weak and hostile proposal of Hori (1963) that predominant reactions are absent. sexual tendency is coupled with a ‘social The ‘three-bird flight’ appears to have tendency’ in the case of three-bird flights evolved as a form of ‘compromise behavi­ (though the latter may be a factor inducing our’ resulting from conflicting tendencies. some males to join in attempted rape This is indicated by the various ‘levels of flights). In the Shoveler particularly, three- intensity’ in these flights detected by Hori bird flights occur at a time when the pur­ (1963) and Smith (1963). The diagnostic suing male is intolerant of other males and feature of Hochbaum’s ‘territorial defense a tendency to be sociable is virtually absent. flights’ was the return of the pursuing Since overt hostility toward the male of male to his starting point. This is the a pair can be associated with the pursuit pattern so typical of the Blue-winged Teal of his mate, the possibility that chasing and Shoveler, in which pursuits are short. males are responding (at least in part) Again the importance of the pair-bond is aggressively to the female should not be shown, the quick return reflecting the overlooked. The phenomenon of ‘re­ male’s attachment to his mate. directed aggression’ (Bastock et al., 1953) In theory, the pursuit of the female of a may be involved: when a male’s tendency strange pair by a paired male could be to attack another male is inhibited, he motivated by either attack tendency, rape re-orientates his hostility toward the tendency, or a combination of the two. As female. I have suggested (Table II), these two

Table II. A comparison of the broad features of social behaviour and some characteristics of pursuit flights in three species of Anas. stage of mate’s Amount of time paired male spends breeding cycle Pintail Mallard Shoveler Early X XX XXX Alone on waiting area Late 0 0 XXX

Early XXX X 0 Associating with other males Late XXX XXX X

Early 0 X XXX Attacking other males Late 0 0 XXX

Early XXX X X Attempting to rape strange females Late XXX XXXX

Characteristics of pursuit flights

Average height XXXXXX Average duration XXXXXX Average distance covered XXX XX X Frequency of flights involving only 3 birds XXX XXXXXX Frequency of flights involving many males XXX XXX X Aggression between males in flight 0 X XXX

The ratings X, XX, X X X represent relative degrees of development of each behaviour pattern (or characteristic) in the three species (0 = absent). These approximate ratings are based on the studies of Dzubin (1955), Hochbaum (1944), Lebret (1961), Smith (1963), Sowls (1955), and on my own observations. ‘Early’ = pre-laying, laying and early incubation; ‘Late’ = late incubation.

BREEDING BEHAVIOUR IOI Dispersion and aggregation of pairs especially vulnerable to predation and in practice such sharing of a localised nesting All ducks lead semi-aquatic lives: they area occurs only on islands or in other need both water areas and adjacent land situations where nesting losses are low. areas to satisfy all their needs. The detailed Precise homing to the nest-site and the nature of these requirements vary between establishment of dense nesting colonies do species, in accordance with different ways occur as a typical pattern in the Common of life. Extreme cases are represented by Eider. A major factor producing such the Ruddy Duck and the Laysan Duck colonies seems to be the lack of mammalian Anas laysanensis. The former is almost egg-predators. On mainland areas, Eider exclusively aquatic, but it is dependent on nests are farther apart (Lack, 1954). The marsh edges for nesting and brood-rearing social behaviour of this species is adapted cover. The Laysan Duck is predominantly to colonial nesting, pairs showing only mild terrestrial: it makes only limited use of salt hostility toward one another. In contrast, water and apparently is capable of surviving male King Eiders Somateria spectabilis without fresh water (Warner, 1963). Most are more aggressive in the nest area species fall between these extremes, making (Pettingill, 1959)3 and this species does not daily use of water areas and shorelines, but form colonies on islands. each has slightly different habitat-pre- Nesting concentrations occur on islands ferences. Above all, the ecology and in lakes, the most famous being at Myvatn behaviour of each species are influenced by in Iceland (Scott, 1952). A hatching success the pattern of land-water interspersion in of 90% has been recorded in 160 nests on the habitat. Gadwall Island, North Dakota, in contrast These relationships between land and to an average of 50% for the same species water areas can be extremely complex. (mostly Gadwall) on the mainland nearby Even for one species they may differ from (Hammond and Mann, 1956). Compara­ one region to another; frequently they tively dense breeding populations of change in the course of one season, and Goldeneye and Wood Duck have been from one year to the next. The need for built up gradually over a number of years most species to be adaptable to varying con­ in various places in Europe and North ditions is obvious, and it is not surprising America by saturating an area with pre­ to find that some parts of the breeding dator-proof nesting-boxes. In addition to range of each pair are ‘shared’ with other homing and high productivity, an addi­ pairs. To understand the pattern of pair- tional factor in producing these nesting spacing, it is necessary to know the degree concentrations may be a tendency for to which this sharing occurs and the way females to be faithful to a site where a in which it is achieved. Particularly import­ nesting attempt has been successful ^Man­ ant is ‘the distribution of the breeding dali, 1958). requirement which is most limited’ (Smith, Hammond and Mann (loc. cit.) found 1955)- This sharing is obvious where the that the Gadwall was especially prone to requirement takes the form of ‘an island’ - form island nesting concentrations. Mal­ whether it is a true island in the sense of an lard, Pintail, Lesser Scaup, and Redhead isolated land mass, or whether it is an also used these same islands but the isolated water area, food source, waiting numbers of Shoveler and Blue-winged area, or tract of nesting-cover. Teal were no greater than on nearby main­ The sharing of one or more breeding land habitat. At Myvatn, Greater Scaup requirements by a number of pairs may Aythya marila and Oldsquaw Clangula be advantageous or disadvantageous to the hyemaIis were the most abundant nesters, species, and complex ‘mechanisms’ have but here also many other species used the evolved which tend to preserve the opti­ islands (Scott, loc. cit.). In southern mum condition of adaptedness. In ducks, Alberta, Keith (1961) found that Lesser as in many other animals, social behaviour Scaup and Mallard favoured islands, while patterns appear to be of prime importance Black Ducks are known to concentrate on in the operation of these ‘mechanisms’ (see islands off the coast of Maine (Gross, 1945) Wynne-Edwards, 1962). and in Chesapeake Bay (Stotts and Davis, Homing by both adult and young i960). In other regions, all these species females must produce a tendency for may be found nesting in a dispersed breeding pairs to become concentrated. If pattern; their use of islands apparently the homing is precisely to the nest-site, a results from local traditions built up dense colony would tend to form; if the gradually as a result of especially favourable birds return merely to the ‘home range’, conditions for high production. a less concentrated aggregation of nests For the Aythya species, the increased would result. In many environments, proximity of pairs caused by nesting on however, concentrations of nests are islands probably presents little difficulty

102 THE WILDFOWL TRUST since these birds show a low level of ducklings are presumably adaptations for aggressiveness and they do not engage in the long overland trips necessary to reach aerial pursuits. Gadwall, Mallard, and water. At Kindersley, Dzubin finds similar Black Duck do show these responses, wide dispersion of nests in the Mallard however, and in some ways their behaviour (up to I mile from water), probably as a must be modified to enable nesting con­ result of intense chasing activity. Although centrations to occur. The mobility of pairs egg-predation may be reduced by this is probably important, so that not all dispersion, duckling mortality is high in activities need be accomplished on the dry seasons, up to 40% of broods never island. Hammond and Mann believe that reaching water. many Gadwalls use the islands only as a In contrast to the Mallard and Pintail, place for a nest-site; they fly to and from the Shoveler behaves in a way much more feeding and resting places on the mainland. like that of a territorial . T he home On the other hand, the Black Ducks of range is small, and males are aggressive Chesapeake Bay have waiting areas on the toward any intruder. The pair-bond is island shore at the spot nearest to the nest ; strong and promiscuous tendencies are although aggressive encounters and aerial weak. This type of behaviour produces a chases were observed, these were con­ clear pattern of pair-spacing, the nest being sidered to be ‘surprisingly infrequent’ situated close to the mate’s waiting area. (Stotts and Davis, loc. cit.). Thus, largely through hostility between In the grassland area of Kindersley, pairs there is a tendency for nests to be Saskatchewan, Alex Dzubin (in litt.) has spaced out. The behaviour of this species studied the behaviour of a high Mallard appears to be adapted to marsh habitats population in which many pairs are forced which provide all requirements of the pair to share small water areas (e.g. 25-30 pairs within a relatively small, discrete area. to a 5-acre pothole). In contrast to the For this reason, the Shoveler is a good behaviour of this species in parkland example of a species with highly developed habitat where there are many potholes ‘territorial behaviour’ of the type envi­ close together, the Kindersley Mallard saged by Hochbaum. drakes are unable to exclude other pairs from specific waiting sites. There is The functions of chasing frequent shifting of areas from which males In ducks, as in other birds (Hinde, 1956), begin chases and, because of the constant there is little direct evidence on the effects presence of other pairs nearby, chasing is of chasing. The frequency and intensity of directed mainly at birds flying overhead, chasing by males have been observed to especially females going to and from their increase as the number of pairs in an area nests. Dzubin concludes that some pairs increases (e.g. Hammond and Man, 1956; are forced to delay nest-initiation when Mendall, 1958; McKinney, in prep.), or they are constantly chased away from such when habitat changes enhance the visibi­ a water area. When the chasing activities lity of adjacent pairs (Hochbaum, 1944). of early breeding males wane in intensity, It is generally assumed that, under such there is a chance for other pairs to become conditions, the density of breeding pairs is established and begin breeding. I have being limited by chasing, and that the same observed the same phenomenon when process is effective to a lesser degree at Shoveler pairs are crowded in pens. lower densities. In some instances, how­ In contrast to the Mallard, which may ever, it appears that breeding populations be found breeding in a wide variety of can increase in density almost indefinitely habitats, the Pintail appears to be speci­ in spite of chasing (Hammond and Mann, ally adapted to nesting in the vicinity loc. cit.; Gates, 1962) and some authors of a ‘water island’. Pintails prefer open (e.g. Bezzel, 1959) have suggested that prairie and tundra where nesting cover is chasing has little effect on duck popula­ sparse and water areas few and often tions. isolated. The studies of Smith (1963) in In this paper, I have tried to show how southern Alberta show that the lack of such contradictory views can be reconciled. aggressiveness between males allows many Although the evidence is circumstantial, I pairs to make use of one lake for feeding believe that chasing tends to produce some and nesting, but the extreme development degree of dispersion and that it has a of raping activity tends to cause dispersion significant effect on breeding densities. The of females at the time of nest-site selection, absence of a neat pattern of exclusive thus producing dispersion of nests. Smith territories with defended boundaries does believes that this nest dispersion has survi­ not necessarily conflict with this generali­ val value in reducing the level of egg- sation. The ability of pairs to share certain predation. The mobility of Pintail broods parts of their home ranges and to adapt and the grey cryptic coloration of the their behaviour to local habitat conditions

BREEDING BEHAVIOUR I °3 can be essential, adaptive attributes. The the species-composition varies so much behaviour of each species must be the from one area to another that the response result of a compromise between the would have to be very generalised. In advantages of spacing-out and those many cases, such behaviour would entail derived from sharing the available re­ ‘wasted’ energy, chases being directed at sources. birds which are not using the same type of Hochbaum (1944) suggested that the nesting cover. The same principle seems primary function of territorial behaviour to apply in other groups of birds, inter­ in ducks is that it permits uninterrupted specific territorialism having evolved only copulation between the members of the where its advantages are great. The pair, but there is little evidence to support occurrence of interspecific hostility in this theory. Eiders successfully accomplish Barrow’s Goldeneye is of great interest and copulation under the crowded conditions it deserves further study. prevailing at colonies, and I found the Geyr (1924) suggested that territorial same to be true in artificially crowded pairs behaviour in the Mallard ensures an of Blue-winged Teal and Shoveler. It is adequate food supply for the brood. In true that interruptions occur but, viewing theory this could be an important ultimate the problem from an evolutionary point function of pair-spacing, but the evidence of view, it is difficult to believe that it had suggests that it is of secondary importance to be ‘solved’ through the enormous in ducks. Broods have considerable powers expenditure of energy involved in chasing. of mobility and, in most duck breeding Hochbaum’s argument depended mainly habitats, food supply is abundant. The on the timing of chasing behaviour; it argument that pair-spacing produces nest peaks in frequency and intensity just dispersion may apply in some cases also to before and during egg-laying, at the time broods, high densities being more vulner­ when fertilisation must be occurring. This able to predation, but again direct evidence generalisation has since been confirmed in is lacking. On the whole, dispersion of pairs a number of species (e.g. Sowls, 1955; is more likely to be primarily an anti­ Dzubin, 1955; Mendall, 1958; Gates, predator device ; if young are not produced, 1962; Smith, 1963). As well as being the there is no need for a food supply. period of fertilisation, however, this is the time when nest-sites are selected. In the Acknowledgements Pintail, Smith (1963) believes that disper­ The interpretations presented in this paper sion of nests over the available habitat is a evolved in the course of observations on direct consequence of sexual chasing breeding ducks made at Delta Waterfowl activity, but in other species the effect Research Station, Manitoba. I am grateful is probably indirect. In the Shoveler, to the Wildlife Management Institute, Mallard, and Gadwall, chasing appears to Washington, D.C., for supporting this produce a spacing of pairs at the time when research. Most of the ideas were discussed they are establishing home ranges. On with the participants at one or more of six mainland habitats, where preferred nest- seminars held at Delta (McKinney, 1957- ing-cover is dispersed, this will lead to a 1962), and credit for many of the facts and dispersion of nests. Evidence from nesting points of view presented here belongs to concentrations (p. 96) strongly suggests these colleagues. For their contributions that such nest dispersion has survival value to these discussions, I am particularly as an anti-predator device. This suggestion indebted to Charles W. Dane, Alex was made with respect to gulls by Tin­ Dzubin, Dr. John T. Emien Jr., Merrill C. bergen (1952) and the same idea was Hammond, Helen Hays, Dr. H. Albert proposed by Hammond and Mann (1956) Hochbaum, Dr. Howard L. Mendall, Dr. for ground-nesting ducks. The survival Richard E. Phillips, Dr. John P. Rogers, value of nest dispersion in Black-headed Dr. Niko Tinbergen, and Peter Ward. My Gulls Larus ridibundus has since been greatest debt is to Dr. Robert I. Smith, demonstrated experimentally by Tinbergen not only for stimulating discussions of his et al. (1962). research and ideas, but also for permission In areas where many species of duck to quote extensively from his two unpub­ nest side by side in the same nesting cover, lished theses. I am grateful to Alex Dzubin, it is perhaps surprising to find that inter­ Dr. John T. Emien Jr. and Merrill specific territorialism (Simmons, 1951, Hammond for detailed criticisms of the 1956) is not widespread. Presumably the manuscript. None of these persons are advantages of such responses in producing responsible for errors of fact or interpreta­ dispersion of all duck nests are outweighed tion in this paper, and I do not wish to by the disadvantages of the time and effort imply that they necessarily agree with what which would be required. Furthermore, I have written.

104 THE WILDFOWL TROST References BASTOCK, M., D. m orsis and m. MOYNIHAN. 1953- Some comments on conflict and thwarting in animals. Behaviour 6: 66-84. Be l l r o s e , f . C ., k . L. Jo h n s o n and T. u. m e y e r s . 1964. Relative value of natural cavities and nesting houses for Wood Ducks. J. Wildl. Mgmt., 28: 661-676. EBZZEL, E. 1959. Beiträge zur Biologie der Geschlechter bei Entenvögeln. Anz. Orn. Ges. Bayern, 5: 269-355. COOCH, G. 1957. A report on the biology and management of the Northern Eider (Somateria mollissima borealis), Cape Dorset Area, N.W .T. Can. Wildl. Serv., unpubl. report. D ix o n , j. 1924. Nesting study of the wood duck in California. Condor 26: 41-66. Dzubin, A. 1955. Some evidences of home range in waterfowl. Trans. 20th N. Amer. Wildl. Conf.: 278-298. DZUBIN, A. 1957. Pairing display and spring and summer flights o f the Mallard. Blue Jay 1 5 : 1 0 - 1 3 . EMLEN, J. T. Jr. 1957. Defended area ? - A critique of the territory concept and of conventional thinking. Ibis 99: 352. ERSKINE, A. J. 1961. Nest-site tenacity and homing in the Bufflehead. Auk 78: 389-396. e v a n s , c . D. and K . E. b l a c k . 1956. Duck production studies on the prairie potholes of South Dakota. U.S. Fish and Wildlife Service, Spec. Sci. Rpt. Wildlife-. No. 32. e v a n s , c . D ., A. s. h a w k i n s and w. H. m a r s h a l l . 1952. Movements of waterfowl broods in Manitoba. U.S. Fish and Wildlife Service, Spec. Sci. Rept. Wildlife: No. 16. f r i t h , h . j . 1959. The ecology of wild ducks in inland New South Wales. II. Movements. C.S.I.R.O. Wildlife Research 4: 108-130. g a t e s , J. M . 1962. Breeding biology of the Gadwall in Northern Utah. Wilson Bull. 74: 43-67. g a t e s , J. M . and J. R. BEER. 1956. A marsh bird study spring 1955. Flicker 28: 16-21. g e y r v o n schweppenburg , h . 1924. Zur Sexualethologie der Stockente. J. f. Om. 72: 102-108. g e y r v o n schweppenburg , h . 1961. Zum Verhalten der Stock- und Schnatterente. J .f. Orn. 102: 140-148. girard, G. L. 1939. Notes on life history of the Shoveler. Trans. 4th N. Amer. Wildl. Conf.: 364-371. g l o v e r , f . a . 1956. Nesting and production of the Blue-winged Teal (Anas discors Linnaeus) in Northwest Iowa. J. Wildl. Mgmt. 20: 28-46. g r o s s , a . o . 1945. The black duck nesting on the outer coastal islands of Maine. Auk 62: 620-622. gudmundsson , f . 1932. Beobachtungen an isländischen Eiderenten (Somateria m. mollissima). Beitr. Fortpfl. Vögel 8: 85-97. Ha m m o n d , m . c . and g . e . m a n n . 1956. Waterfowl nesting islands. J. Wildl. Mgmt. 20: 345-352. HEINROTH, o. 1911. Beiträge zur Biologie, namentlich Ethologie und Psychologie der Anatiden. Verk. V. Int. Orn. Kongr., Berlin: 589-702. k i n d e , r . A. 1956. The biological significance of the territories of birds. Ibis 98: 340-369. h o c h b a u m , h . a . 1944. The Canvasback on a Prairie Marsh. Amer. Wildl. Inst., Washington, D.C. h o r i , j . 1963. Three-bird flights in the Mallard. Wildfowl Trust 14th Ann. Rep.: 124-132. h o r i , J. 1964. The breeding biology of the Shelduck Tadorna tadorna. Ibis 106: 333-360. HOWARD, H. E. 1907-14. The British Warblers. London. HOWARD, H. E. 1920. Territory in Bird Life. Murray, London. k e i t h , L. 1961. A study of waterfowl ecology on small impoundments in south-eastern Alberta. Wildl. Monogr. No. 6, 88 pp. k o s k im ie s , J. and e. ROUTAMO. 1953. Zur Fortpflanzungsbiologie der Samtente Melanitta f. fusca (L.). I. Allgemeine Nistökologie. Papers on Game Research, 10. l a c k , D. 1939. The behaviour of the Robin. Pt. I . The life history with special reference to aggressive behaviour, sexual behaviour and territory. Proc. Zool. Soc. Lond. 109: 169-178. LACK, D. 1954. The Natural Regulation of Animal Numbers. Oxford. lebret, T. 1961. The pair formation in the annual cycle of the Mallard, Anas platyrhynchos L. Ardea 49: 97-158. LEOPOLD, f. 1951. A study of nesting wood ducks in Iowa. Condor 53: 209-220. lo w , J. b. 1945. Ecology and management of the redhead, Nyroca americana in Iowa. Ecol. Mon. 1 5 : 35- 69- MCKINNEY, F. 1961. An analysis of the displays of the European Eider Somateria mollissima mollissima (Linnaeus) and the Pacific Eider Somateria mollissima v. nigra Bonaparte. Behaviour, Supplement 7. 124 pp. m ckinney, f. 1957-62. Reports of six annual seminars held at Delta Waterfowl Research Station (mimeo). m endall, h. l. 1958. The ring-necked Duck in the Northeast. Univ. of Maine Studies, Second Series, No. 73, 317 pp. M unro, J. A. 1939. Studies of waterfowl in British Columbia: Barrow’s golden-eye and American golden-eye. Trans. Royal Can. Institute 22: 259-318. MUNRO, J. A. 1942. Studies of waterfowl in British Columbia: buffle-head. Can. Jour. Res., Sec. D. 20:133-160. MYRES, m. T. 1957. An introduction to the behavior of the goldeneyes: Bucephaia islandica and B. clangula (Class Aves, Family Anatidae). Unpublished M.A. Thesis, University of British Columbia. n i c e , m . m . 1943. Studies in the life history of the Song Sparrow. II. Trans. Linn. Soc. N.Y. 6 : 1-328.

BREEDING BEHAVIOUR 105 References— continued PETTINGILL, O. S., Jr. 1959- King Eiders mated with Common Eiders in Iceland. Wilson Bull. 7 1 : 2 0 5 -2 0 7 . REED, A. 1964. The nesting of the Black Duck (Anas rubripes) at Ile aux Pommes, Quebec. Paper presented at Northeast Wildlife Conference, Hartford, Conn., January 1964. (Mimeo.) SCOTT, P . 1952. Myvatn 1951. Severn Wildfowl Trust 5th Ann. Rep.: 125-132. SIMMONS, K. E. L. 1951. Interspecific territorialism. Ibis 93: 407-413. SIMMONS, K. E. L. 1956. Territory in the Little Ringed Plover Charadrius dubius. Ibis 98: 390-397. SIREN, M . 1957. Telkän pesimisseutuja Pesäpaikka uskollisuudesta. Suomen Riista 11: 130-133. sm ith, R. I. 1955. The breeding territory and its relationship to waterfowl productivity at Ogden Bay Bird Refuge. Unpublished M.S. Thesis, Utah State Agrie. College, Logan. sm ith, r. I. 1963. The social aspects of reproductive behavior in the Pintail (Anas acuta acuta, L.) Unpublished Ph.D. Thesis, Utah State University, Logan. s o w l s , l . k. 1955. Prairie Ducks. Wildlife Management Institute, Washington, D.C. STOTTS, v. D. and D. E. DAVIS, i960. The Black Duck in the Chesapeake Bay of Maryland: breed­ ing behavior and biology. Chesapeake Science 1: 127-154. Tinbergen, N. 1939- Field observations of East Greenland Birds, II. The behaviour of the Snow Bunting (Plectrophenax nivalis subnivalis (Brehm)) in spring. Trans. Linn. Soc. N.Y. 5: 1-94. Tinbergen, N. 1952. On the significance of territory in the Herring Gull. Ibis 94: 158-159. Tinbergen, N. 1957. The functions of territory. Bird Study 4: 14-27. TINBERGEN, N., G. J. BROEKHUYSEN, F. FEEKES, J. C. W. HOUGHTON, H. KRUUK and E. SZULC. I962. Egg shell removal by the Black-headed Gull, Larus ridibundus L. ; a behaviour component of camouflage. Behaviour 19: 74-117. WARNER, r . E. 1963. Recent history and ecology of the Laysan Duck. Condor 65: 3-23. W e id m a n n , u. 1956. Verhaltensstudien an der Stockente (Anas platyrhynchos L.). I. Das Aktions­ system. Zeitschr. für Tierpsychol. 13: 208-271. WYNNE-EDWARDS, V. c. 1962. Animal Dispersion in relation to Social Behaviour. Edinburgh and London.

Breeding success of geese in west Spitsbergen, 1964 M. NORDERHAUG, M. A. OGILVIE and R. J. F. TAYLOR

Sum m ary Details are given of the distribution of breeding Pink-footed, Barnacle and Brent Geese in Spitsbergen and of their past status. Counts were made in the south-west of Spitsbergen in the summer of 19Ó4. Few young Barnacle Geese were reared but Pink-foot were more successful. Many nests were found and the factors affecting the choice of nest site are discussed: freedom from snow cover is the most important. Introduction T o p o g ra p h y In the summer of 1964 two expeditions, The topography of the south-west coast of one from Norway and one from Britain, West-Spitsbergen is characterised by a flat visited adjacent parts of West-Spitsbergen plain varying in width from one to six with the object of investigating the status, miles and never rising above 3 0 0 feet. distribution and breeding success of the Steeply sided mountains reaching 3 ,0 0 0 Barnacle Goose Branta leucopsis Pink- feet form a boundary on the eastern edge footed Goose Anser brachyrhynchus and of the plain. Two wide and extensive Brent Goose Branta bernicla hrota. fjords, Bellsund and Homsund, and one The Ornithological Group of the Norsk large glacier, Torellbreen, break the area Polarinstitutt, consisting of L. Ljoterud, into three distinct parts, geographically but B. Mathiasson (assistants) and M. Norder- not ecologically. There are numerous off­ haug worked from 7th July to 31st August shore islets and rocks, of which the largest in the coastal region from Stormbukta such as the Dunöyane and Isöyane groups north to Ohlshomen/Kapp Berg (areas and Ohlsholmen are barely one square 1-4 on map). They also continued their kilometre in area. They are low, grass- Little Auk Plautus alle studies, begun covered and with a few small, shallow in 1962. The Wildfowl Trust Expedition ponds. Large parts of the coastal plain are of R. J. F. Taylor and M. A. Ogilvie nearly barren or with scant vegetation. It covered the coastal area between Isfjord is only round ponds and streams and close and Bellsund (partially) and from B ells und to the foot of the mountain cliffs with their south to Kapp Borthen, from 18th June to very large colonies of sea-birds, mostly 26th July. The two expeditions worked in­ Little Auks, that the richest vegetation is dependently, but study methods had been found. An association between these lush co-ordinated beforehand. areas and the distribution of the geese is

106 THE WILDFOWL TRUST GEESE IN SPITSBERGEN IO7 apparent. The single large valley of Dun- were caught and ringed whilst moulting in derdalen, over ten miles long, has con­ Reindalen in 1954 and geese in small siderable areas of poorly vegetated bog numbers have been recorded breeding in with small lush bits round the few ponds. Sassendalen and adjacent valleys. Rein­ The middle and upper parts of the valley dalen has been visited by oil prospectors are more barren still. The inner regions of in the past few years, but it is not known the two fjords were not visited. what effect this has had. Breeding was recorded from the Isöyane islands in 1924 Weather conditions (20 pairs) and from the nearby Dunöyane The winter of 1963-64 was characterised group in 1952 (12 broods). Another known by heavier than normal snowfall and an breeding area is in the extreme north-west unusually cold spring resulted in a late of the archipelago, where 20 pairs were thaw, with 100% snow cover still present found on a small islet off Dansköya visited at the Radio and Meteorological Station at by the Norsk Polarinstitutt expedition ship the mouth of Isfjord until 5th June. The in June 1964. thaw was rapid when it came, with only 50% cover by 25th June, and the snow Breeding success of the Barnacle had gone completely from the coastal Goose plain by 17th July. The end of June and In area 1 of the map, no Barnacle Geese the first half of July was generally fine were found breeding or with young. In with little snow or rain. Thereafter until areas 2-4 all likely breeding localities the end of August the weather was predo­ were visited and searched during August minantly wet with comparatively warm and all used nests counted. It is unlikely winds. Most of the drift-ice disappeared that many sites or nests were not found. from the south-western coasts during the In area 5 no nests were located, but accu­ first week of July. rate counts were made of the number of broods of goslings. There were no records Barnacle Geese of Barnacle Geese in areas 6-8. Table I Ringing of Barnacle Geese in the Horn- shows the numbers of geese and nests sund area in the summer of 1962 (Larsen found. The total population counted was and Norderhaug, 1963) and on the Solway in excess of 1,511 with a gosling proportion Firth, Scotland, in the following winter o f io-o% . (Boyd, 1964) had confirmed an earlier Table I. Numbers of Barnacle Geese inference that the flock of Barnacle Geese wintering on the Solway Firth, numbering and their nest-sites counted, West- 3,000 in 1962-63 and 4,300 in 1963-64, Spitsbergen 1964 came from Spitsbergen and was a popula­ Parents Nests tion entirely separate from the stock seen or and Non­ breeding in east Greenland and wintering estimated Goslings broods breeders in west Scotland and Ireland, and from that breeding in Arctic Russia and winter­ Area 1 ___ — ing in Holland and Germany. 2 332 6 2 16 6 2 50 + Apart from the non-breeding flocks 3 180 - 90 ? totalling 1,100 birds found in the Dunöyane 4 40 71 20 220 Islands off Hornsund in 1962 (Larsen and 5 50 18 25 289 Norderhaug, 1963) and the much smaller numbers found breeding there (at least 35 total 60 2 151 30X 759 + pairs) in 1963 (Norderhaug, 1964), records from Spitsbergen were scanty and gave The main hatching period occurred little indication of where the birds might before the breeding areas were visited, and now breed in numbers. Lavenskiold only a handful of nests still in use were (1964) summarises the pre-war position found. At Dunöyane on 14th July a few and gives his own observations from many nests with eggs and one with hatching eggs parts of the Svalbard archipelago which, were recorded. From observations of the however, were mostly made in the early age of goslings seen, the main peak of 1950’s when the Barnacle Goose popula­ hatching was probably 4th to nth July. tion was much smaller than at present There is excellent agreement between (Atkinson-Willes, 1963). He indicates two independent records made in areas 2, 4 and known breeding areas, both small. The 5. Counts were made of the number of colony in Longyeardalen was exterminated goslings in each brood seen, and the mean before 1931, probably by human activity size of 59 broods was 2-6. It was not from the nearby mine. The maximum size possible to estimate the proportion of of this colony is unknown, but possibly not goslings in the flocks in areas 2 and 3, but more than 50 pairs. 23 Barnacle Geese in areas 4 and 5 it was 13-4%.

108 THE WILDFOWL TRUST Because of the incomplete counting in Brent Goose some areas and the unknown rate of failure of nests, it is not possible to use This species is scarce in the areas visited. these figures to make a reliable estimate Six used nests were found in area 2 and the of the total population. probable number of birds in this area was The great majority of the nests were on under 70. A short visit was made on 31st islets and skerries off-shore. Cliff-nesting, August to Sorkappoya south of West- common in Greenland, has only been Spitsbergen where 120 geese were seen. recorded in Spitsbergen from the Long- Some of these had been there the whole yeardalen colony. In areas 4 and 5 many summer but most had only arrived during of the family parties were on and around the last week o f August, probably gathering large lakes on the mainland. Although no prior to migration (Dr. S. Siedlecki, pers, geese were found in areas 6-8, there seems comm.). no major ecological difference between Choice of nest-site by Arctic-nesting these areas and where the Barnacle Geese geese were found. There thus seems to be no barrier in this part of Spitsbergen to Selection of nest-site is probably governed further increases in the Barnacle Goose by numerous factors. Freedom from snow- population. cover at the time of laying (calculated peaks in 1964 were 25th May to 2nd June Pink-footed Goose for the Pink-footed Goose and 2nd to 9th Birds of this species were breeding in areas June for the Barnacle Goose) is the most I, 2 and 4 to 7. Nests were found in areas 6 important. As mentioned above, the choice and 7. The numbers of young and non­ of site by the Pink-footed Goose is far breeders were accurately counted in areas more catholic than that of the Barnacle 4-7. The peak hatching period estimated Goose and this is clearly an adaptation from nests found and age of young seen brought on by the longer incubation and, was xst~7th July, a few days earlier than in particular, fledging periods of the former for the Barnacle Goose. The choice of nest- necessitating an earlier start to breeding. site was very varied, including rock out­ The interval from first laying to the final crops, the tops o f low cliffs and 100 feet or fledging of young is about 88 days for the more up steeply inclined grass-covered Pink-footed Goose and 75 days for the mountain slopes. Table II shows the Barnacle Goose. The Barnacle, with its numbers of adults and young counted. The preference for islands, can afford to wait. proportion of young in areas 4-7 was Islands, of course, are more likely to be 41 -4% and the mean brood size in all areas free from Arctic Foxes, though there are was 2-7 (70 broods). records of these animals crossing to islands The Pink-footed Goose breeds almost on sea-ice and causing great damage to throughout Svalbard wherever conditions nesting birds (Lovenskiold, 1964). The are suitable (Lavenskiold, 1964). From Pink-foot seems unworried by foxes; in ringing in West-Spitsbergen in 1953 and one area six nest-sites were found within 1954 (Goodhart, Webbe and Wright, 1955, 400 yards of a fox earth containing a vixen Holgersen, 1956) it is known that these and three two-months-old cubs. Eggshells birds winter in Germany and Holland. The in the nest and goslings in the neighbour­ size of this population is between 7,000 hood suggested successful hatching of at and 10,000 (Dr. M . F. M örzer Bruijns and least some of these nests. Thus the Pink- J. Phillipona, in litt.). foot’s varied choice of nest-site seems governed by the dominant factor of lack of Table II. Numbers of Pink-footed snow cover, and the previously documented Geese counted, West-Spitsbergen 1964 requirements for freedom from predators and also of a vantage point for the gander Non­ (Lovenskiold, 1964) seem to be conse­ Parents Young breeders Total quences of this rather than criteria in their own right. Good feeding, both for the Area 1 8 10 270 288 nesting birds and for their young within a 2 30 38 116 184 reasonable distance is an obvious considera­ tion; proximity to an expanse of water, 3 -- - 0 fresh or salt, can be assumed to be second­ 4 16 21 3 40 ary to this. 200 yards was the maximum 5 0 O 25 25 6 106 146 170 422 recorded for the distance from nest-site to good vegetation. The immediate nest- 7 8 II 60 79 site sometimes included a modicum of total 168 226 644 1038 shelter for the sitting bird, a low rock for example, but the influence of this in the

GEESE IN SPITSBERGEN IO9 selection of the site would only seem to be Sletbakk for their practical help in the in terms of the final few inches. crossing of Bellsund. M.A.O. is indebted to the Wildfowl Trust for the opportunity Acknowledgements for, and financing of, his part in the work. We are grateful to the Norsk Polarinstitutt M.N. would like to express his thanks to for their help and advice, especially in the L. Lj0terud and B. Mathiasson for their shape of their expedition ship M/V never-failing interest and skill during the ‘Signalhorn’ and its captain and crew. field work; to N. Gullestad for help during M.A.O. and R .J.F.T. would like to express his stay in Hornsund ; and to the Nor­ their thanks to the head and staff of the wegian Game Research Institute for special Isfjord Radio Station, Kapp Linné for financial support of the goose studies. their assistance, and to A. Paulsen and E. References Atkinson-W illes, G. L. (Ed.). 19 6 3 . Wildfowl in Great Britain. 368 pp. Nature Conservancy Monograph No. 3 . H.M.S.O., London. boyd, H. 1961. The number o f Barnacle Geese in Europe in 1 9 5 9 -6 0 . Wildfowl Trust 12th Ann. Report: 1 1 6 - 1 2 4 . boyd, H. 1964. Barnacle Geese caught in Dumfriesshire in February, 19 6 3 . Wildfowl Trust 15th Ann. Report : 7 5 - 7 6 GOODHART, J., R. WEBBE and T. w right. 1955- Goose-ringing in Vest-Spitsbergen 19 5 4 . Wildfowl Trust yth Ann. Report: 1 7 0 - 1 7 6 . holgersen, H. 1957. Kortnebbgjess (Anser arvensis brachyrhynchus) i den kaide ettervinteren, 19 5 6 . Stavanger Mus. Arbok, 1956: 150-158. larsen, T. and m. norderhaug. 1963. The ringing of Barnacle Geese in Spitsbergen in 19 6 2 . Wildfowl Trust 14th Ann. Report-. 9 8 -1 0 4 . L0VENSKIOLD, H. L. 1964. Avifauna Svalbardensis. 46 0 p p . Norsk Polarinstitutt Skrifter Nr. 12 9 . Oslo. norderhaug, m . 19 6 4 . Ornitologiske feltarbeider p â Vestspitsbergen 1 9 6 3 -6 4 . Sterna, 6 : 1 8 5 - 1 9 4 .

The numbers o f waterfowl in Estonia SVEN O N N O Institute of Zoology and Botany, Academy of Sciences of the Estonian S.S.R.

Sum m ary About 2 7,0 0 0 pairs of ducks of 1 4 species, 500 pairs of Greylag Geese and 10 pairs of Mute Swans have bred annually in Estonia in recent years. Mallard (10 ,0 0 0 pairs) are most numerous, though they and Velvet Scoters (1 ,1 0 0 ) and Pochard (400) are decreasing. Eiders (3 ,50 0 pairs), Shoveler (2 ,5 0 0 ) and Scaup (90) are increasing. Much larger numbers occur on passage in spring and autumn, including over a million Long-tailed Ducks and Velvet and Common Scoters, over 10 0 ,0 0 0 Bean Geese and over 50,000 Whooper Swans. Few wildfowl winter, 3,0 0 0 Aiallard being the most plentiful.

Introduction (Table I), and the nests of most of the The intensive ornithological research of local breeding ducks have been traced. the last ten years may now be summed up The data for the littoral are less complete. to furnish provisional data on the numerical At least two-thirds of the Estonian coast, strength of the waterfowl in Estonia. that extends for about 3,400 kms (2,100 Counts of local breeders have been taken miles), are uncongenial as a breeding in a number o f Estonian habitats. T h e most ground for the majority of the geese and accurate returns we possess cover the bird ducks, which exhibit a marked preference population nesting in the archipelago. for the deeply indented shores of the Estonia possesses nearly 800 small islands numerous coastal lakes and those sectors with a surface area not exceeding 100 of the western seaboard and the south hectares (250 acres), of which the majority coast of Saaremaa Is., where coves, inlets are densely populated. Ornithological and bays are thickest. Counts of the water­ researches of a more detailed character fowl in these regions were mainly taken have been carried out in the four areas along chosen routes during the nesting where the population is densest. Together season. But more exact figures are available they contain some 180 islets, sandbanks, for the ducks in the Matsalu National Park, etc. (Figure 1). In each of these areas where most of the nests in a number of counts have been taken in from two to six sample areas were traced and charted. The years in the course of the past decade information obtained was sufficiently re­

n o THE WILDFOWL TRUST Figure i. The Estonian SSR - I maritime islands covered by ornithological research: I. Vilsandi and environs. 2. The Väinameri (Muhu Sound). 3. The Suur Väin (Great Sound). 4. Matsalu Bay. II Investigated sectors of the littoral: 5. Matsalu National Park. 6. Environs of Puhtu Bird Station. Ill Bays and coastal lakes rich in vegetation 7. Matsalu Bay, 8. L. Linnulaht, 9. L. Kahala, 10. L. Soitsjärv. IV Counts of migratory ducks: II. Puhtu, 12. Viinistu. presentative to justify the use of correction lakes that merge with the sea at high water. coefficients to calculate population densi­ These have dense breeding populations, ties. Apart from Matsalu, where counts and most of our lacustrine and maritime have been made every year, beginning from ducks are concentrated here. The largest 1957, a number of other short stretches of of the bays is Matsalu, with about 2,000 the coast have been similarly dealt with hectares (5,000 acres) o f reed beds, where from time to time (see Figure 1 and the bird population has been calculated Table II). with reasonable accuracy over a number of There are about 1,100 lakes in Estonia years. At the same time we have data for with a surface area exceeding one hectare. the breeding populations of most of the Most of them are oligotrophic and sparsely so-called Estonian ‘bird-lakes’ in certain vegetated, with the result that they are years. T h e larger and better known of them unable to support any considerable popula­ are marked in Figure 1, and a few indica­ tion of waterfowl. On the other hand we tions concerning the predominant species have about 50 eutrophic lakes, and about will be found in Table III. the same number of bays, inlets and coastal Only approximate figures can be given

WATERFOWL IN ESTONIA III Table I. The population of breeding geese and ducks on the smaller maritime islands of Estoma

Environs Väinameri Suur Väin Matsalu of Vilsandi (Muhu Sound) (Great Bay Sound) number of islands 50 70 50 IO

Somateria mollissima 2500 4 50 5 - Aythya fuligula 5 220 300 80 Melanitta fusca 150 2 50 100 - Anas clypeata 50 n o 15 0 35 Mergus merganser 15 0 13 0 IO 5 Anas platyrhynchos 50 90 90 40 Anser anser 120 40 5 15 Mergus serrator 60 So 25 2 Anas querquedula 5 35 30 20 Anas acuta IO 15 15 2 Aythya marila 50 5 5 i Tadorna tadorna 20 30 5 — Anas crecca 5 10 IO - Aythya ferina - 5 1 Anas streperà --- 2

iable II. The population of breeding geese and ducks on the most suitable stretch of the Estonian shore

Matsalu Puhtu Bird Station National Park and environs (120 kms.) (30 kms.)

Anas platyrhynchos 16 5 20 Anas clypeata 160 20 Mergus merganser 55 50 Anas querquedula 160 10 Melanitta fusca 2 70 Aythya fuligula 2 15 Anas crecca — 5 Anas acuta 35 I Mergus serrator - Tadorna tadorna 2 I Anser anser 5 3 Somateria mollissima

Tables III. Ducks and geese breeding in richly vegetated biotopes (coves, bays, coastal lakes) near the Estonian coast

Reed-beds in Matsalu Bay L. Linnulaht L. Kahala L. Soitsjärv area (in hectares) 2000 1 1 7 345 223

Aythya fuligula - 50 70 15 Anas platyrhynchos 250 10 5 5 Aythya ferina 150 25 3 15 Anser anser 1 7 0 2 -- Anas querquedula - 10 2 3 Anas clypeata - 10 4 1 Anas crecca — 2 i I Melanitta fusca - 5 5 - Mergus serrator - 2 - - Aythya marila - 3 - - Cygnus olor 2 — — Anas acuta 2 -- — Mergus merganser 5 - -- Anas streperà 2 —— -

112 THE WILDFOWL TRUST for tie numbers of breeding ducks in the outline of the migration. The average remaining habitats, though the data for the figures for the spring flight at the Puhtu peatbogs and about 100 of the bigger lakes Bird Station are as follows: Long-tailed may be regarded as fairly satisfactory. Ducks 300,000, Common Scoters 200,000, Elsewhere we can piece together little and Velvet Scoters 150,000. On 20th April, more than a fragmentary picture, in spite 1957, counts taken in the central part of of the small size of the local nesting com­ Matsalu Bay yielded 40,000 W hooper and munities. As for the lakes and bogs Bewick’s Swans, 30,000 Goldeneyes, investigated, no more than 17, or at the 20,000 Mallards, 12,000 Pintails, 10,000 most 18, of the 35 species of geese and Tufted Ducks, 9000 Wigeon, 8,000 Scaups, ducks (with 37 subspecies) found in i,oco Shovelers and 800 Goosanders. Estonia can be shown to breed here. The autumn flight, observed at Viinistu Approximate numbers giving a rough idea on the north coast in i960 and 1962 (ióth of the distribution of the breeding geese September to 15th October), gave the and ducks in the above-mentioned groups following averages : Long-tailed Ducks of biotopes are given in Table IV. In 400,000, Velvet Scoters 23,000, Common presenting the data, the figures, wherever Scoters 16,000, W igeon 6,000, Scaups 6,000 possible, cover the past ten years. However, and Brent Geese 4,000 (data supplied by it should be borne in mind that important A. Jogi). The 1957 figures for Puhtu and modifications are at present taking place in its immediate environs during the same the numbers of several local breeding period were: Long-tailed Ducks lco,coo, species. The Eider, and probably also the Velvet Scoters 17,000, Scaups 12,000 and Scaup, shows a marked upward trend. The Common Scoters 10,coo. numbers of Shovelers have persistently The Long-tailed Duck and the Velvet risen during the last two decades. In recent and Common Scoters are mainly concen­ years some species, such as the Mute Swan trated along a narrow route closely follow­ and Gadwall, have shown a tendency to ing the littoral, and muster in huge flocks expand over Estonian territory. On the on the north-western coast. Most of the other hand the numbers of Mallard, Velvet birds keep to the west of the islands, though Scoters and Greylag Geese are steadily a considerable channel of the spring migra­ diminishing. The Pochard, which between tion flows down the straits separating the ten and twenty years ago was rapidly islands from the mainland. Only a few increasing as a local breeder in Estonia, has individuals prefer to strike overland in the during the last decade entered on a new direction of Lake Peipsi (Peipus). Other decline. species that cling to the seashore are the As for the migratory geese and ducks White-fronted and the Lesser White- which appear in Estonia as birds of passage fronted Goose, and the Barnacle and only, 26 species have been recorded in Brent Goose, the last of which is rarely transit. These are shown in Table V, met with outside the north-western coastal arranged more or less in order of numerical area. The other birds may be observed in strength. almost any part of the country, while the During the last ten years the regular Smew actually occurs most frequently in observations carried out at a number of the region of Lake Peipsi. points on Estonian territory during the In the last few years a special network autumn flight have produced abundant of observers has taken counts of wintering data for the numbers of migratory geese ducks in Estonia. The most populous of and ducks. Of particular interest are the these is the Long-tailed Duck, which may results obtained at Puhtu and some of the be seen flocking in tens of thousands in the observation posts along the north coast open sea. Other prominent wintering (Figure 1). For several years counts have ducks are the Goldeneye and Velvet Scoter. been taken of the diving-ducks passing The Goosander, Eider and Red-breasted Puhtu in the spring, and of the ducks and Merganser are somewhat less numerous. geese halting to rest in the Matsalu The Smew, Scaup, Tufted Duck and National Park. The total strength of the Common Scoter rarely winter in Estonia. migration is rather difficult to determine When the weather is mild the Whooper in the case of the surface-feeding ducks, Swan, and of recent years the Mute Swan which move mainly at night. All we have also, may occasionally be met with on the to go by here are the results of daytime seaboard. counts taken at the more popular halting- The commonest duck wintering inland places. The data for these species, there­ is the Mallard, o f which about 3,000 indivi­ fore, represent no more than an approxi­ duals linger in the vicinity of the ice-free mate estimate. streams and watercourses, where they are With these reservations we may now accompanied by a few solitary specimens proceed to sketch in a broad statistical of the Teal and Bean Goose.

WATERFOWL IN ESTONIA 113 Table IV. The numbers of geese and ducks nesting in Estonia

Small Coastal area Total of maritime open bays & Other breeding Recent islands shore lakes biotopes pairs changes

Anas platyrhynchos 3 4 4 4 I0 3000 + d e c r e a s in g Somateria mollissima 4 I -- 3500 increasing Aythya fuligula 4 2 4 I 3000 Anas clypeata 4 4 2 - 2500 increasing Anas crecca 2 2 i 4 2000 Anas querquedula 2 4 3 2 2000 Mergus merganser 3 4 i - 12 0 0 Melanitta fusca 4 3 i - 1100 decreasing Anser anser 3 i 3 - 500 decreasing Aythya ferina I 3 40 0 d e c r e a s in g a fte r in c re a s e Mergus serrator 3 2 I - 400 Anas acuta 2 3 I I 350 Tadorna tadorna 2 2 - - 15 0 Aythya marila 2 - I - 90 in c r e a s in g Bucephaia clangula --- 2 50 Cygnus olor - -I- 10 in c r e a s in g Anas streperà I - i - 5 Anas penelope — “ I? ?

4 = numerous (over 500 breeding pairs); 3 = common (100-500 breeding pairs); 2 = scanty (25-100 breeding pairs) ; I = a few solitary individuals (less than 25 breeding pairs).

TableJV. Strength of the passage of geese and ducks through Estonian territory

Clangula hyemaIis several millions

Melanitta nigra about I million Melanitta fusca

Anas platyrhynchos Bucephaia clangula Aythya marila 100.000-500,000 Anas penelope Anas crecca

Anser fabalis Cygnus Cygnus Anas acuta 50.000-100,000 Aythya fuligula Anser albifrons

Branta leucopsis Mergus serrator Cygnus bewickii Mergus merganser 10.000-50,000 Branta bernicla Anser erythropus

Aythya ferina 5.000-10,000 Anas clypeata Anas querquedula 1.000-5,000 Mergus albellus

Somateria mollissima less'than 1,000 Anser anser } Anas streperà occasional strays

114 THE WILDFOWL TRUST The nesting and some other habits of Alopochen, Nettapus, Plectropterus and Sarkidiornis Captain C. R. S. PITMAN

Summary African ‘geese’ are catholic in their choice of nest-sites. Most Egyptian and Spur-winged Geese nest on dry ground, but may use holes in trees, or old arboreal nests of other birds. Pygmy Geese occasionally nest on the ground but more often in trees or on buildings. The Knob-bill nests in trees and in Africa at least also on the ground. Clutch-sizes and parental behaviour are discussed. There is some evidence that Sarkidiornis may often be polygamous in Africa, though appa­ rently not in India. Alopochen and Plectropterus roost on water, the latter also sometimes on dry land. Sarkidiornis roosts chiefly in trees, though sometimes on mudbanks or floating islets. The roosting places of Nettapus are not known. Flocks of Alopochen and Plectropterus sometimes cause serious damage to crops, by trampling or nibbling maize, beans, and sweet potatoes and pulling up entire ground-nut plants.

Introduction nest site I was shown near Entebbe was Commonly known as ‘geese’ the members some 30 feet above the ground in the of the four tropical genera Alopochen, crown of a palm and was only discovered Nettapus, Plectropterus and Sarkidiornis when the goslets were seen falling from it. differ in many respects from those of Anser All these sites were close to water, but in and other closely allied genera. Delacour South Africa a nest three feet up in a (1954-64) and other authorities, treat the ‘mopane’ tree was 200 yards from water. Egyptian Goose Alopochen aegyptiacus as a An unusual site was in the thatch of an member of the tribe Tadomini, which occupied African hut; the dry grass of the includes the sheld-ducks and South thatch was pushed up to form a tunnel American sheldgeese, and puts the other about a foot long and the nest - there were three genera in the tribe Cairinini, along no eggs - was lined with down. Nests have with the wood ducks and the Muscovy been found in ant-heaps and in the tree- Duck. But in its nesting, feeding and social nests of other birds, in particular, inside habits, with which this paper is concerned, the huge structures of the Hammerkop or Alopochen is much like the perching geese. Hammerhead Scopus umbretta. In South Africa a nest - of grass but with no Nesting habits down in the lining - was found in a heavy Nettapus auritus - african pygmy goose clump of grass on a river bank; and one in OR DWARF GOOSE Northern Rhodesia, by a shallow 2 i acres This particularly lovely little goose - the pan in ‘mopane’ woodland, an untidy male with its exquisitely handsome head - grass structure under a log, on mud, and is found on lakes, lagoons, dams and back­ about 20 yards from the water’s edge. At waters. I knew it well in many parts of the same pan there was another Pygmy Uganda and, though widespread, less Goose nest - a rough structure of grass commonly in Northern Rhodesia. When I containing six eggs, but no mention of first went to Entebbe (on Lake Victoria), down - in fairly deep water. These last two Uganda, in 1925, I knew of four nests records are of particular interest as they which I did not disturb. One was in a hole indicate that the Pygmy Goose will nest on in an ironstone cliff and the others 30 to the ground even when there is woodland - 40 feet up in holes in large trees. These and the probability of suitable nest holes - were all in the same locality where Sir near at hand. There is an important factor, Frederick Jackson (a Governor of Uganda) however, which may have influenced these had previously found a nest at arm’s Pygmy Geese for in this locality there is a length in a hole, seven feet above the considerable population of large, deadly, ground in an ironstone cliff. This same predatory Black Mambas which freely hole and others near by in the low ironstone explore holes in trees. In the virtually cliff had been regularly tenanted by wild treeless vast open and swampy country of Grey Psittacus erithacus until Nigeria where the Pygmy Goose is com­ systematic robbing of their nearly fledged mon, it can only nest on the ground or in young eventually drove them away. Jack­ swamp. son found other Pygmy Goose nests in The nest is variously described as con­ trees at Entebbe respectively at 30 feet and structed of dry twigs, coarse grass and 60 feet above the ground - the latter in a leaves, etc., sometimes lined with down hole at the end of a dead branch. Another and (Jackson records) with a little green

HABITS OF AFRICAN WILDFOWL US moss. The usual complement of pale which contained the remains of their nests creamy-white eggs varies from 6 to 9, and which were said to be used year after though Delacour (1959) records up to 12; year. Various authorities on Indian birds and from the data available the African describe the nests as constructed of twigs, Pygmy Goose lays fewer eggs than either grass, dead leaves and feathers - but no the Cotton Teal or Green Goose-Teal. down - and at any height above the ground So few nests have been found, that as from water level to 30 feet up, though the yet little is known about the breeding majority are at about six to twelve feet; a behaviour of the African Pygmy Goose. nest sited as high as 68 feet has been found At Entebbe, a brood of eight newly hatched in a hole in a building at Rangoon, Burma goslets was caught by an African who had and another at 40 feet was in a niche i n a trapped the parent; an attempt to keep factory chimney. A nest has also been them in captivity failed as the parent recorded i n an ant hill at the base of a tree escaped and the brood died. The African and another - a nest of grass - on top of an Pygmy Goose is as agile as the Cotton ant hill. Nest holes usually have a wide Teal when entering its nest hole in a tree entrance, yet when they are as small as or cliff, vide Jackson’s graphic description four inches across these birds fly into them ‘shot in as nimbly as a Sand Martin or with the greatest accuracy, without pause Kingfisher’ ; he also recorded that the or hesitation. mother goose was accompanied to the In Burma, a Cotton Teal with five eggs cliff face by the drake. The female must was found nesting in the same tree-hole as be able to check itself in a remarkable way a Comb Duck, which had six eggs; all so as to enter a small aperture and its eleven eggs are in the National Collection restricted space seemingly at top speed. at the British Museum (Natural History). Watch as assiduously as I might, during Nests may also be placed in ruined houses, the breeding season, rarely did I see the temples and old chimneys, but Stuart- brooding female - she was not always Baker challenges the authenticity of two accompanied by the male in her flight - nests described as ‘a semi-floating nest on enter the elevated cliff-hole. The approach the water, among the rushes or lotus was not direct and when the two birds leaves, of weed, grass, etc., all together’. were together they flew several times to This is an observation of days long bygone, and fro at the correct level until one since when there has been no other such suddenly swerved into the hole. If one did Indian record. But this does not mean that not watch carefully one missed the split the record is valueless, for in Australia second entry on the realisation there was N.pulchellus, the Green Pygmy Goose, will only one bird visible instead of two ! nest on the ground and in swamp, as N.auritus, the Dwarf Goose, also does in Nettapus coromandelianus - COTTON TEAL Africa. or Indian pygm y goose, and in Australia, For the size of the bird the complement where it is usually classified as N .c. of pale creamy-white eggs - usually varying albipennis, white-quilled pygmy goose from six to fourteen - is relatively large, Or WHITE-QUILLED GOOSE TEAL. and as many as 16, 18 and 22 have been When serving in the Indian Army, prior to recorded. A nest containing a total of 40 the First World War, I was familiar with eggs suggests competition for a nesting site the little Cotton Teal of south-east Asia, and more than one female responsible. The New Guinea and Australia in the course of male, though often accompanying the several shooting expeditions to the Central female to the nest hole, never enters. Provinces. As it breeds during the monsoon when the rains make the jungle impassable Sarkidiomis melanotos - knob-billed I had no opportunity of investigating its GOOSE, KNOB-BILL, COMB DUCK or NUKTA. breeding habits. In these jungles when I knew the Knob-Bill much better in there is no other permanent water the Africa than in India, where its nesting widely scattered villages are each sited habits have long been well known, whereas alongside a ‘tank’. A ‘tank’ may be either in Africa reliable records are almost as few quite small or of considerable size accord­ as those of the Dwarf Goose. In India, ing to the terrain and is an artificial expanse with rare exceptions, nests are in trees, of water created by an earth dam to retain usually in holes and hollows mostly within the rainy season’s surface flow. On these six to twelve feet of the ground, but ‘tanks’ were populations of Cotton Teal in occasionally even as high as 30 feet. pairs or groups, or in small concentrations Occasionally the Knob-Bill appropriates not large enough to be designated flocks. the nests of other birds, sometimes at Around them, in mango and other trees, I considerable heights, for its eggs have been was shown many hollows and holes, some found in a Vulture’s nest, in the nest of the eight to twelve feet above the ground, White-tailed or Pallas’ Fishing Eagle

116 THE WILDFOWL TRUST Haliaëtus leucophyrys and once in a nest eggs found in Southern Rhodesia was in a of the Woolly-necked Stork Dissoura tree hollow, several feet deep, and quarter episcopus. Other sites include holes in o f a mile from water. As these little goslings ruined forts and amongst rocks, once a nest are skilful climbers and as a distance o f 440 was found in a hole in a bank and a deep yards is not beyond the bounds of possi­ grass nest has been recorded in a swamp bility of the brood having walked to the amongst thick growth. As a rule nesting water, it is a faulty premise ‘Undoubtedly trees are near water - though occasionally carried out of this cylindrical hollow by at a considerable distance - or even stand­ the male and female’. Another nest in a ing in water. The nests are of small sticks hollow tree in Southern Rhodesia was at a and grass lined with dead leaves and a few height of 50 feet and it was said that the feathers, but no down; at times there may young tumbled out of the nest. Some of be virtually no nest. Seven to twelve eggs the young were caught, but easily escaped is the usual complement. 40 and 47 eggs, by climbing out of an open, deep packing which have been recorded, are presumably case. Eleven eggs have also been taken attributable to more than one female. But from a hollow tree in a swamp in Nigeria. the most astonishing total of 54 was found Seven eggs recorded from nests in thick in a hole in a mango tree, with a nine inches reeds over fairly deep water in Nyasaland wide entrance, six feet above the ground are of dubious authenticity. In Nigeria a and nearly four feet deep. T h e eggs did not nest has been found in reeds. Only once hatch and were deserted. The finder did I find a nest in Uganda - in a deep suggested that it might be a communal nest hollow amongst the stone blocks of a and certainly one could reasonably claim disused pier - on Lake Victoria; it con­ that no less than four females must have tained two fresh eggs. The Knob-Bill, in produced so large a total. This suggests the small numbers, breeds regularly along the possibility of more than one female at­ northern Lake Victoria littoral - but as the tempting to brood at the same time, which local inhabitants are disinterested - I was would explain why some of the deserted unable ever to locate a nest, though I was eggs were cracked. The idea of a communal once told about one in a hole in a tree nest, apart from possible competition for which I was unable to visit. Every year nesting sites, raises the question of poly­ near Entebbe, in September, when out in a gamy, more especially as this record refers launch I used to come across broods, and I to one male with five females being was sometimes surprised to find how far observed nearby. The subject of polygamy out on the lake they would be. On one will be referred to below (p. 119). In occasion I spent the best part of a day, various parts of south-east Asia, according when engaged on fishery investigation on a to the local inhabitants whose reliability small lake in south-west Uganda, in can I think be accepted, communal nests searching the numerous hollow trees on containing multiple egg clutches are well tiny islets where these geese were said to known and two females have been seen to nest, although I was warned that it was enter the same nest-hole. the wrong season. It was not a particularly In Nyasaland, at the commencement of healthy pursuit for these islets were the rains, Knob-Bills arrive in hundreds infested with Puff Adders - on what they along the Lower Shire river and its fed I did not find out - and some were a adjacent swamps, and it may be that they few feet up in hollows in the trees. The are attracted to suitable nesting sites in the Puff Adder is a powerful swimmer and numerous Hyphaene and Borassus palms. buoyant as it partially inflates itself when This is a well-defined movement though I in the water. It was not an attractive doubt if it is a migration. A nest with eight lakelet for the only craft available were eggs was found in a hole 12 feet up in a bundles of reeds tied together and these dead Hyphaene, but it was one mile from soon became water logged, while at the water, and the finder realised too late that edge of a swamp the overhang of a huge had he made a thorough search o f the many sloping rock - above which in a small, dead palms he might have found more shrubby tree was a nest of the Goliath nests. In this connection the question arises Heron Ardea goliath - was covered with as to how the young got to the water one dozens of combs of vicious wild bees. mile distant. It is categorically stated, with The same nesting holes are said to be reference to South Africa ‘Young removed used year after year; this is well known in from nest on parent’s back’ but I am India. unaware of the evidence on which this is In Africa the usual complement of based. Nest sites in South Africa include creamy or pale yellowish eggs varies from holes in trees and boles, in long grass and six to eleven, which differs little from the among stones on a low hill. A nest of ten seven to twelve recorded in India.

HABITS OF AFRICAN WILDFOWL I I 7 Plectropterus gambensis - s p u r - w i n g e d attract attention it is possible that un­ GOOSE deserved prominence has been given to its tree-nesting proclivities. I am inclined to The nests of Spur-winged Geese though believe that only a relatively small pro­ occasionally in trees or on cliffs are mostly portion of Egyptian Geese nest in trees and on the ground, sometimes a considerable that the majority of nests are on the ground distance from water. I used to know of a where they are rarely found. Nests are of number of tree-nests, none higher than 20 grass and similar material, profusely lined feet, in old raptor nests in the woodland at with the parents’ down which is used to the southern end of Lake Nakuru, in cover the eggs when the bird is away from Kenya. Like the Egyptian Goose, the the nest. Nests on the ground or at ground Spur-wing will lay on top of the Hammer- level may be in a reed bed, in grass or kop’s massive structure, from which I rashes, on floating water plants, on low, imagine the young are called down. The Spur-wing, too, nests in rather arid condi­ flat grass-covered islands, in matted vegetation near water, amongst rocks on tions on elevations of nearly 6,000 feet islets, in a rocky cleft on a river bank, above the 3,000 feet high western scarp among boulders in a rock cleft in a cave, of the great Rift Valley, at Uganda’s frequently on a river bank, amongst the extreme north-east comer. Goslings are broken stonework of a lake pier, on an ant- seasonally seen there on some of the numerous pools, many of them saline. heap, in the disused burrows of porcupines and ant-bears, and in an old boat-house. Ground nests are usually well hidden in The Egyptian Goose is thoroughly at dense, long grass, not far from water, or home in the trees and is equally adept at in reed beds, but the Spur-wing seems to perching on the tops of flat-topped thorny prefer to nest on dry ground rather than acacias as on solid boughs. It frequently on the water - where standing space on a appropriates the old nests of other species. nest is extremely limited. Nests vary from Nests of my own finding include : in a Fish large, bulky grass structures, when in Eagle’s nest at the top of a flat-topped swamp, to shallow hollows scantily lined acacia 80 feet above the ground and a with grass; there is no down. Nests have Goliath Heron’s nest at the top of an been found on termite hills; another was Albizzia about 60 feet up - in both these under a low bush 15 yards from a river cases the goose nests which are usually well bank. shaded were very exposed to a fierce sun, The usual complement of large, ivory- but I also found another goose nest on the white eggs is hard to judge as records vary flat top of a lofty rock which must have from six to twelve, but sets of six and seven fresh eggs do seem to suggest incomplete been excessively hot for the brooding bird except when it was dull or raining. On a sets. Unusually large sets of 15 and 16 eggs ledge a few feet below this goose nest was are known, but as a rule I think sets consist the occupied nest of a Lanner Falco of eight to twelve eggs. This goose and its biarmicus, but its young flew before the young are much preyed on by crocodiles. The Spur-wing will lead its brood to goslings hatched. Others were in a hollow of a cliff face some 12 feet above water water from a considerable distance; both level on an islet; on top of Hammerkop parents look after the brood. At the Whip- nests (several) ; in the broken stonework of snade Zoological Park, in Bedfordshire, one of these geese hatched her brood of ten a pier; on a tiny islet, in scrub, amongst some half-a-mile distant from the nearest several nesting crocodiles - all about 11 feet; and on another islet which harboured water and when the parents and their many sluggish, massive Puff Adders and goslings, on the move, were set upon by a large (6 feet to 8 feet) Black-lipped Cobras pair of aggressive Saras Cranes Grus antigone the geese successfully saw off the - how the eggs successfully hatched and the brood survived, as it did, was quite attackers. astonishing. But at certain seasons ample food was available for the snakes from a Alopochen aegyptiacus - E G Y P T IA N g o o s e large nesting colony of Grey-headed Gulls The nesting habits of this well-known, Larus cirrocephalus and ground-nesting noisy, quarrelsome species are bewildering colonies of Sacred Ibis Threskiornis in their diversity for it may nest on the aethiopicus. Crocodiles are accustomed to ground or as high as 80 feet in trees or in a lie above their buried eggs (incubation variety of other sites, and at altitudes from period c. 90 days) to protect them from sea level to nearly 13,000 feet, though the predators such as the voracious Monitor latter occurrence (Hachisuka, Bull. B.O.C., Lizard Varanus niloticus and Hyenas. 52: 18-19,1931) is quite exceptional. Tree- These crocodiles always return to the nesting is a characteristic of this goose, but water by the same runway. The goose nest as nests above the ground are likely to found on the Crocodile breeding islet was

118 THE WILDFOWL TRUST in an old runway, with runways in use on Hammerkop was seen to emerge from a either side of it. How did it know where it nest on which an Egyptian Goose was would be safe ? An unusual site in South perched. The goose and Hammerkop were Africa was on a small islet in the centre of a never observed to come into contact on the breeding colony of some 300 pairs of the top of the nest. According to Turner, the Greater Phoenicopterus ruber. Egyptian Goose seems to breed all the year Even stranger is a 1963 record from South round in the Seronera region of the Africa of an Egyptian Goose unmolested Western Serengeti, in Tanganyika. sitting on ten eggs on a small island where The usual complement of creamy-white a female Cape Otter Aonyx capensis and eggs varies from six to ten, but sets of 11, three young were living. The island was 12 and 15 (two were infertile) are known. strewn with hundreds of duck eggs which Nests of my own finding varied from seven the otters had collected for food from to nine eggs. Records I have of several nearby islands. Layard (1875-84) records dozen nests include more than two dozen finding a nest in South Africa on a ledge of sets of nine and over a dozen of eight, rock amongst a breeding group of eight figures which may indicate the normal Cape Vultures or Kclbe’s Griffons Gyps clutch size; sets of six and seven, too, are coprotheres from which it possibly derived numerous. a measure of protection, as the Vultures Early wastage amongst the broods seems were friendly disposed towards it. common, for though 7 to 11 goslings may Other nests have been recorded in the hatch and reach the water and are con­ fronds of a palm tree about 15 feet above stantly guarded by both parents, they are the ground; 10 feet from the ground in a subject to attacks by four-footed, feathered stunted thorn tree on a kopje overlooking a and aquatic predators, and are soon perennial stream; in hollow trees; on reduced. In the water coarse fish such as flood debris in a bush; at various heights on Cat-fish (Silurids) and Eels, Nile Perch cliffs ; and on precipices sometimes as much (Lates), (which in the past annually took as 200 feet above water. It is unusual for the whole gosling broods which hatched in nests to be far from water; occasionally the Giza Zoological Gardens at Cairo), they may be a quarter of a mile distant and Monitor Lizards (Varanus), Water Tor­ rarely as much as a mile; ah the nests I toises Pelomedusa subrufa, which cause found were close to water. Egyptian Geese much loss to goslings in parts of South nest very commonly on the top of the Africa, and Crocodiles (where they occur) enormous structures built by the Hammer- are all responsible for considerable 'wastage. kop. Van Ee (1963) records finding three Crocodiles too have been seen to take adult Hammerkop nests occupied inside by Egyptian Geese and at Entebbe, on Lake Egyptian Geese which contained 6, 10 Victoria a 5 A foot, enormous Lungfish and 15 eggs, all of which hatched with Protopterus aethiopicus choked itself to the exception of two infertile eggs in the death trying to swallow a full-grown last. He records ‘In watching the approach Egyptian Goose. of the geese to the nests I noticed that one flew straight in to the somewhat bigger Polygamous behaviour of Sarkidiornis opening while the other two clung to the Many dams were created all over Uganda, nest before entering’. Ten goslings in one from 1945 onwards. Most of these attracted nest 25 feet above the ground, in the small populations of Knob-Bills, but I Zoological Gardens at Bloemfontein, were never came across any nests, though not carried down by the parents but fell, seasonally broods would be seen on them. after the two parents were observed calling The most interesting feature of these from the ground. Even when goose nests populations was their composition, which are as high as 60 and 80 feet there is a definitely suggested polygamy, for the possibility that the goslings may be ‘called’ Knob-Bills were always in groups - rarely to jump down, for I noticed there was more than one or two groups unless a dam always an abundance of secondary growth, was of considerable extent - which con­ to break the fall of the youngsters, beneath sisted of one male and three or four females. such heights - but this is just a conjecture. Much of the day was spent by a group In the western region of the Serengeti perched in one dead tree. There is no National Park in Tanganyika Myles Turner evidence of polygamy in South Africa, but (in litt.) has twice seen an Egyptian Goose this may be due to the sexes being equally and a Hammerkop using the same nest. T h e represented, for where the females pre­ Hammerkop on arrival perched on a low ponderate - as has been recorded in West branch below the nest, which was about Africa - polygamy is likely. It has been nine feet above the ground and then dived recorded that to keep Knob-Bills success­ into the nesthole. The sitting goose fussed fully in captivity there must be a consider­ a bit, but not unduly. Another time a able preponderance of females to males,

HABITS OF AFRICAN WILDFOWL II9 otherwise a male will constantly pursue and Plectropterus were widespread, abundant exhaust a female during the breeding and tame, but the introduction of firearms season. This behaviour seems to indicate quickly put an end to such a happy state and a natural tendency towards polygamy. The numbers all too rapidly dwindled. Only male is more than twice the size of the fifteen years ago I still knew of utterly wild female. places in Uganda where in the early morning Major Ian Grimwood, Chief Game dozens, mainly in pairs, of confiding, fearless Warden of Kenya, has kindly sent me the Alopochen grazed right up to one’s tent and following comments. ‘I have no evidence would scarcely move out of the way to let one pointing to Knob-bill being polygamous pass. This is a wonderful recollection of and the only three nests I have found have something which will never happen again all been solitary in position. Even in the for ‘progress’ long ago decreed the dis­ breeding season these birds seem most appearance of these refuges. In East Africa frequently to be found in parties but sex- I have exceptionally come across flocks (or ratios seem to be completely flexible, e.g. concentrations) respectively of Alopochen three males in “full knob” with five females and Plectropterus of several hundreds, or I male and three females which were on though as a rule they are a good deal my dam at various times last rains. smaller. These flocks mostly consist of a ‘Curiously enough a professional hunter number of family parties and are usually was yesterday, 27 February (1964), talking seen either in shallows, on sandbanks, on of a small pan on which he had just been land close to water or when feeding. It has camping in Tanganyika which was occu­ been recorded that Alopochen by night rests pied by two males, four females and two on the water - it would be safe from broods of Knob-bill ducklings compared crocodiles where the water is about 20 feet with one male, three females and two deep and over - and that Plectropterus broods last year.’ roosts on a convenient bank or similar safe Despite Major Grimwood’s opening site. M y comment is that I have often come remarks, these records do seem to suggest across Alopochen far out on a lake late at a degree of polygamy, more particularly night, and have occasionally in the darkness the occurrence of a male with three females disturbed Plectropterus roosting on land, and two broods. but I hesitate to say more than that m y own Polygamy by Sarkidiornis in India does experience would sometimes appear to not seem to have been suggested. This support the record. Before leaving the divergent behaviour may not be so strange subject of flocking it can be mentioned that as might at first seem for in India the where the three larger species are common curious Painted Snipe Rostratida bengha- one will sometimes see - especially Alopo­ lensis is polyandrous which my own chen and Plectropterus - several broods observations certainly indicate, yet in East together in the water particularly when the Africa where I, and others, have had juveniles are fairly large. Parents may be considerable experience of this species absent, but there is usually an adult or a there is no evidence to suggest that it is sub-adult with them. Associated with other than monogamous. flocking is flighting and where Alopochen and/or Plectropterus are numerous there Roosting and flighting wih be evening and morning flights to the Sarkidiornis feeding grounds whether they be natural The Knob-bill is not so nocturnal as most grazing, cultivated grassland or stubble. In ducks, though resting a lot by day. In the Chad region of Northern Nigeria it has India where its habitat is normally associ­ been recorded that in these evening and ated with trees it has been described as morning flights Alopochen invariably pre­ ‘strictly tree-loving’ and it is probable that ceded Sarkidiornis and Plectropterus. Some there it always roosts in trees; but in the forty years ago near Lake Nakuru in Kenya tree-less swamp regions of Africa it rests I was able for several weeks to witness the on mud-banks and floating islets. In the flights of Alopochen and Plectropterus to the well-treed parts of Africa where I was maize stubbles and I can confirm that it familiar with this species it certainly spent was the former which first flighted on to much of the day perched on trees, parti­ the feeding grounds; the regularity of their cularly dead trees standing in the water of timing was remarkable. The flight, varying recently created dams. A check with a torch considerably in intensity according to the revealed that the Knob-bills roosted on weather, usually lasted from twenty to these trees for much of the night. thirty minutes, and inevitably in the middle of the flight there was an overlap of the two Plectropterus and Alopochen. species. Skeins varied in size from about When the white man first penetrated South­ a dozen to a few score birds, some of which ern and Eastern Africa Alopochen and were calling as they flew. Although these

120 THE WILDFOWL TRUST geese regularly were shot at they did not just before dawn, but though easily scared become unduly wild, and seemed reluctant from cultivation, I have frequently seen to change their normal lines of flight. One them unconcernedly raiding a particularly authority has recorded how wary is Plec­ tempting crop in broad daylight. Geese and tropterus when flighting to a feeding ground ducks are incredibly destructive to ground­ which it will circle more than once before nut plots, for to get at the nuts they coming down. This was not my experience destroy the plant. The birds do not dig for at Nakuru where both Plectropterus and the nuts but pull out the plant, with the Alopochen despite much shooting habitu­ nuts attached to the roots. I imagine that ally flew straight to their goal and when the nuts were originally found by chance unmolested settled immediately. when a goose accidentally pulled up a plant. It is a simple matter for the powerful Feeding and damage to crops goose to jerk the plant out of the ground, The Egyptian Goose is usually found in but not so easy for a duck. N ot being strong pairs or groups of pairs or in small flocks enough to uproot the plant directly, the of sub-adults but in parts of South Africa duck, having firmly seized the plant in its it joins up seasonally into vast flocks to raid bill, gyrates around it, meanwhile pulling the wheatlands where it becomes a real hard, until achieving the desired result. pest and causes tremendous damage. Spur- This is an example of the type of curious wings can also cause severe damage, by complaint so often received by a Game trampling, when feeding in flocks in Warden in Africa - havoc caused by ducks growing crops. Like Egyptian Geese, they to numerous ground-nut plots. It sounds are very partial to ground-nuts and to highly improbable, but investigation con­ sweet potatoes. The tops of the sweet firmed its truth; and the culprit, the potatoes are eaten and the tubers are Fulvous Tree-Duck or Whistling Teal ruined by nibbling. Dendrocygna bicolor was not only caught Spur-wings are mainly nocturnal feeders, in the act, but had a crop stuffed with though by day they are sometimes found ground-nuts; every plot examined had on grasslands far from water. These big really been devastated and around each birds can create havoc amongst growing uprooted and discarded plant were the crops of beans and ground-nuts which they unmistakable signs of the modus operandi are accustomed to visit as dusk falls and of the marauder.

White-headed Ducks in Westt- Pakistan CHRISTOPHER SAVAGE

Sum m ary An influx of White-headed Ducks Oxyura leucocephala was observed in West Pakistan in December, 1964. Five specimens were caught and sent to Slimbridge. Some notes are given on their behaviour and measurements. The White-headed Duck Oxyura leucocep- less than thirty published records over the hala is known in India and Pakistan from last hundred years, from which it is classi-

HABITS OF AFRICAN WILDFOWL 121 fied as a fairly regular winter visitor by to themselves, being preoccupied with Ripley (1961). The author, however, feeding almost throughout the day, while counted about 470 on the lakes of the the majority of other ducks present spent Punjab Salt Range on 6th December, the day resting. They could be easily 1964. The lakes are quite large in extent approached in a boat to within thirty to and it is possible that without a powerful forty yards whereupon they dived to escape telescope on a stand the stiff-tails might pursuit. Only occasionally would they take easily have been overlooked amongst the to wing and then usually because other thousands of other waterfowl. It is pro­ birds nearby were doing so. Their take-off bable therefore that the number seen may and flight was grebe-like with a long run not have been as unusual as would appear, before getting airborne and even then they particularly as two weeks later most had flew heavily with very fast wing beats and dispersed and one lake had only 90 whereas seldom attained a height of more than five previously it had held 373. In view of the feet. On the water they held their tails at an increasing rarity of the species in Europe angle of 450 except when disturbed and (Hoffmann, 1964) some notes on its often had a puffy look like the African ecology and behaviour are of interest. White-backed Duck Thalassomis leuco­ The lakes used by the stiff-tail are the notus. less brackish of those in the Salt Range, The white head of the male is very con­ namely Khabbaki, Kallar Kahar and spicuous in December but the bill is a Nammal (with total dissolved salts o f 1,760, slaty colour, not the bright blue of illustra­ 8,060 and 3,180 parts per million respec­ tions which presumably is only present at tively). They are for the most part four to the height of the breeding season. The six feet in depth with little cover vegetation black markings on the head o f the male also but extremely rich in submerged water showed considerable individual variation, herbs such as Ruppia maritima L ., M eli- particularly over the eye and at the back lotus indica (L.) All., Hydrilla verticillata of the head. Some individuals had the Poir. and Potamogeton nodosus Poir. as black extending down the neck to meet the well as yellow-green algae. No stiff-tails dark collar at the base of the neck, and one were found at Uchhali (with total dissolved had a black spot on the cheek behind the salts of 37,520 parts per million) which ear coverts. The females were much seemed devoid of submerged vegetation but duskier than usually illustrated and also rich in blue-green algae. The algae no showed some variation in head marking. doubt attracted the flock of 390 Greater Examination of birds in the hand suggested Flamingoes Phoenicopterus ruber roseus that their autumn moult was complete but which was present. when skinning a casualty some new The stiff-tails generally kept very much growing feathers were found.

Table I. Measurements of White-backed Ducks caught in the Punjab Salt Range, December 1964

zoeight wing culmen tarsus tail gms mm mm mm mm

Male 865 168 46 45 87 794 170 46 46 85 553 159 45 45 92 Female 631 159 45 43 81 610 160 46 41 82 539 160 43 45 75 None showed any recognisable juvenile characteristics

122 THE WILDFOWL TRUST Five specimens were obtained for the food source in the south east of the Wildfowl Trust and were dispatched with Caspian Sea. Measurements of the birds the minimum of delay through the coopera­ handled are given in Table I. tion of the Pakistan authorities. The birds were in fair condition, but the one which Additional note. Numbers continued to was skinned had hardly any subcutaneous build up to a peak of over 700 in February, fat and it is probable that they had not long 1965, and that in spite of heavy mortality arrived from their autumn migration. The from shooting to which ten ducks were an gizzard of the dead bird was found to easy prey. These numbers are a complete contain beside gastroliths a quantity of surprise to local ornithologists, but local small black seeds believed to be of Ruppia hunters say that the species has been as maritima and two kinds of buff coloured common as this for some years now. This seeds, one of which could be of Melilotus is no cause for complacence as it is highly indica. This contradicts Stuart Baker (1929) probable that the increase is due to changes who describes their diet as ‘mainly animal’ in distribution forced upon them by but does support Dementiev and Gladkov disturbance from the Hamun-e Hirmand (1952) who mention Ruppia maritima as a (see p. 125). References

De m e n t i e v , G. p. a n d N . A. g l a d k o v . 1952. Birds of the U.S.S.R. vol. IV. 640 pp. Moscow (In Russian) Ho f f m a n n , L . 1964. Situation de la sauvagine dans les pays mediterraneens d’Europe. Proc. ist European Meeting on Wildfowl Conservation, 196_j: 59-64. Ri p l e y , s. D ., x i . 1961. A synopsis of the birds of India and Pakistan. 703 p p . Bombay. St u a r t b a k e r , E. C. 1929. Fauna of British India - Birds, vol. VI. 2nd ed. 499 pp. London. W a i t e , H. w . 1948. The birds of the Punjab Salt Range (Pakistan). Journ. Bomb. Nat. Hist. Soc. 48: 93- 117-

Wildfowl Survey in south-west Asia: a progress report CHRISTOPHER SAVAGE

Summary A private survey was started by the author during 1964, with the advice and encouragement of the Wildfowl Trust, to study the distribution and status of wildfowl species in southwestern Asia particularly in the context of the human changes which are taking place. The scope of enquiries includes the Middle East, India and Pakistan but ringing of birds will be confined to Iran and Pakistan through the Game Departments of these countries. A reconnaissance was made of the Hamun-e Hirmand in Iranian Sistan where recession of the swamp affects the local economy as well as wintering waterfowl. Information, particularly details of game bags, would be welcomed from Members. Introduction In recent years many changes have been the past has been more than compensated taking place in south-west Asia which by water-logging elsewhere, to the detri­ affect wildfowl. Increasing human popula­ ment of pochards but to the benefit of the tion, improvements in communications surface feeders. This inter-relationship of and greater availability of modem firearms engineering, agriculture and wildfowl have increased ‘hunting pressure’ more ecology, and its implications in terms of than in other parts of the world, while conservation, has been little studied as yet changes in land use have been destroying and it is as a contribution to this study in old habitats and creating new. In West Asia that the author, a civil engineer by Pakistan, for example, drainage of some profession, initiated this survey during the ‘jheels’ much favoured by many species in summer of 1964.

WHITE-HEADED DUCKS IN PAKISTAN I23 The scope of the survey was originally lines used in the recent Nature Conser­ limited to W est Pakistan, but it soon became vancy Monograph Wildfowl in Great obvious that a more useful contribution Britain. could be made by the general study of the region and the coordination of cooperative Progress to date efforts of corresponding observers. At the Searches have been made through available same time close liaison was established with literature to determine where possible the the Game Council of Iran (now the Game position in the past and the extent of Department) and the Game Department gaps in current knowledge. Although the of West Pakistan, both of whom were searches are not complete it is already clear anxious to start a programme of ringing that even today surprisingly little is known and are now conducting departmental except from the museum curator’s view­ wildfowl enquiries of their own, and also point. A most valuable source of informa­ with the vigorous Bombay Natural History tion however has been the game books of Society, who have contributed so much to sportsmen. A number of sportsmen res­ the knowledge of wildlife in the whole ponded to a letter in The Field and many region. more have replied to personal enquiries. The main object of the survey at present Many records unfortunately seem to have is to obtain and evaluate information on been lost at the time o f Partition and during distribution and status of species - informa­ the 1939-45 war, and few people in recent tion which is needed before any real years have kept notes in such detail as in progress can be made in wildfowl conser­ the old days. Information of any kind, vation. The scarcity of qualified observers particularly any old records and details of and lack of continuity in most cases game bags, would be welcomed from precludes anything approaching the ‘wild­ Members and should be forwarded direct fowl counts’ which are so valuable in to the author c/o 11F Gulberg, P.O. Bag Europe, but an attempt is being made to 704, Lahore, West Pakistan. map species and habitat distribution on the Details of 78 recoveries of ringed geese

Table I. Published recoveries of ringed wildfowl marked or found in south-west Asia

Russian rings found in Bombay N.H. S. rings found in India Iran ‘Middle USSR India species Pakistan Iraq East’ Abroad Pakistan Total

Bar-headed Goose Anser indicus 2 _ __ _ Ruddy Shelduck Tadorna ferruginea I ____ I Common Shelduck Tadorna tadorna I _ _ _ — I Pintail Anas acuta 6 2 _ 8 Common Teal Anas crecca 2 4 3 9 Mallard Anas platyrhynchos I 7 _ 3 I 12 Gadwall Anas streperà 3 3 i 2 2 II Wigeon Anas penelope _ _ I 7 I 9 Garganey Anas querquedula 5 _ 3 _ 8 Shoveler Anas clypeata I — 8 2 i 12 Red-crested Pochard Netta rufina _ 2 _ 2 Common Pochard Aythya ferina -- - 3 - 3

22 12 10 26 8 78

124 THE WILDFOWL TRUST and ducks have been traced which throw reeds in spring furnishes building materials some light on migrations in the area and it for housing and boats, and reed products is hoped that appeals in the local press may such as mats and sun blinds from Sistan bring in more. Recoveries to date are are marketed all over Iran. Fishing and summarised in Table I. This is no more grazing by amphibious cattle continue all than a beginning and many more records the year round and provide protein for the are required before even a general picture whole district. Thus there is no doubt that can be put together. Ringing in Pakistan the Hamun is an inseparable part of the will certainly help, but no great advance local economy. can be expected before Soviet authorities The area of swamp today however is extend their ringing programme further much reduced and now depends entirely east, which it is believed they intend to do. on winter floods on the Helmand River. Water storage projects in Afghanistan and Sistan reconnaissance intensified irrigation in both countries will In April 1964 a reconnaissance was made continue to reduce the surplus flood waters of the Hamun-e Hirmand in Sistan, south reaching the Hamun and further recession eastern Iran, which is a great swamp on the of the swamp is inevitable. This is already border of Afghanistan. This area, though causing concern as no alternative grazing an important wintering ground for water­ exists for an estimated 100,000 head of fowl of all kinds, has been ornithologically cattle and the exposed shores of the unexplored since it was visited by Zarudny northern part of the swamp are being at the turn of the century. Few waterfowl eroded by the famous 100-day wind in were present in April and most of the summer, only to aggravate the already Hamun was inaccessible for lack of a suit­ appalling problem of galloping sand dunes able boat. However, some wounded geese which engulf villages and canals. A more were found in captivity: Greylag Geese telling example of the need for coordina­ with pink bill and legs of the eastern race tion of technology and conservation could Anser anser rubrir ostris, and also Lesser hardly be found. White-fronted Geese Anser erythropus. A reconnaissance was also made of the Both species were said to be abundant in lakes in the Punjab Salt Range. From both winter. A large swan with yellow and black areas small collections of swamp plants bill, presumably a Whooper Cygnus have been identified by courtesy of the cygnus, had recently died in captivity after British Museum of Natural History, and being captured a few weeks earlier when water samples have been analysed by Sir wounded. The fishermen and herdsmen Alexander Gibb and Partners in Sistan and said that in summer they collected the eggs the Water and Power Development Autho­ of the Greylag Goose, of which they said a rity in West Pakistan. number stayed to nest, of the White- headed Duck Oxyura leucocephala, which Acknowledgement they knew well, and of Coots. Finally a special acknowledgement is due Heavy shooting and netting of duck in to the Wildfowl Trust whose staff have February and early March is an important spared no efforts to assist in every possible local industry though not quite so much as way the launching of this survey. on the Caspian (Savage, 1963). The crop of References At k i n s o n -W i l l e s , G. L . (ed.). 1963. Wildfowl in Great Britain. Nature Conservancy Mono­ graph No. 3. 368 pp., London. s a v a g e , Ch r i s t o p h e r . 1963. Wildfowling in Northern Iran. Wildfowl Trust 14th Ann. Rep.'. 30-46.

WILDFOWL IN SOUTH-WEST ASIA 125 The geese of Wrangel Island Dr. S. M . USPENSKI

Summary In i960 there were about 130,000 occupied nests of Lesser Snow Geese in their main colony on Wrangel Island. In 1964, when the spring weather was extremely unfavourable for repro­ duction, about 114,000 nests were in use, with about 300,000 geese in the nesting areas. In 1964 the average clutch-size was 3-27 eggs, compared with 5-6 in normal years. Nests in areas where the snow persisted longest and where the bird population was less dense contained fewest eggs. A large number of mature birds failed to nest although their gonads were normally developed. Non-breeders were most numerous in areas where the snow melted late. The average size of young broods was 2-7 goslings, range 1-5. Nesting in 1958 was probably even later than in 1964. 1-2,000 pairs of Pacific Brent Geese were nesting on the island in 1964 and another 10,000 non-breeders were moulting there. Moulting Brent caught included four previously ringed in Alaska, also when moulting.

Introduction snow began to melt only on 24th May, and Wrangel Island i j i 0N, 1800), which has the break-up of the snow covering was long remained uninhabited, is now the delayed by subsequent cold spells. The main world nesting centre of the Lesser adverse weather conditions disturbed the Snow Goose, Anser caerulescens caeru­ normal life cycle of the geese, reducing the lescens. Up to the middle of the last size of the clutches and causing a large century the bird was widely distributed number of birds to refrain from nesting. over the continental tundra of Siberia and There have, of course, been years in which on islands in the Arctic Ocean west to the weather conditions were even less favour­ lower reaches of the River Ob (75°E), as able; for example, according to A. I. well as along the Arctic coasts of North Mineev (1945, p. 364), in 1931 ‘as had America. The birds wintered at this time never happened before, the tundra was in Japan and apparently on the shores of completely covered with snow during the the Caspian, as well as in southern North whole of June and part of July, and there America. The drastic reduction in numbers was a blizzard even in mid-June. We saw and restriction of habitat of the Siberian enormous numbers of geese flying around geese are due principally to their annihila­ in search of nesting sites, but without tion in their wintering grounds, especially success’. in the Far West, on the North American According to the results of question­ prairies, which were extensively colonised naires and our own observations, these by European emigrants in the middle of geese arrive and lay their eggs at the last century. Another contributory factor periods shown in Table I. was obviously the changes in the terrain Observations show that in spring the caused by ploughing the prairies. birds fly to the island on a broad front, The birds’ breeding grounds on Wrangel from the south-east and south-south-east. Island were studied for the first time by the Following this direction, they reach the author in i960. Land and air surveys main nesting site. revealed that the main colony was in the On arrival, the oviducts of the females valley of the River Tundrovaya, near the contained fully formed eggs; the ovaries foot of Tundrovoi Peak. The total number usually also contained 6-8 large ripe of occupied nests in the colony was assessed follicles. However, the birds were unable at approximately 130,000. In addition to to utilise these, and the follicles were the main colony there were several small reabsorbed during the first few days after colonies on the island, and the total num­ arrival. Whereas in years of normal weather ber of nests of this species on the island the clutches consist of 5-6 eggs, the clutch was approximately 200,000, the number of in 1964 was 3 eggs in most cases. It was a nesting birds being 400,000 (S.M. Uspen­ characteristic feature that the nests in parts ski, 1963). In 1964 we carried out fresh of the colony where the snow disappeared investigations to obtain more complete and last and where the bird population was not up-to-date information on the ecology, dense contained the smallest numbers of distribution and numbers of A.caerulescens eggs. On the other hand, breeding was caerulescens. relatively satisfactory where the snow It should be noted that the spring of melted early and where the birds nested 1964 was delayed on Wrangel Island. An densely (Table II). adverse maximum air temperature was T h e failure o f a large number o f mature maintained until 27th May and blizzards birds to nest, although they were well fed occurred up to the end of the month. The on arrival and had normally developed

126 THE WILDFOWL TRUST Table I. Tim ing of events in the breeding cycle of Lesser Snow Geese on Wrangel Island, 1955-64

start of start of start of start of migratory mass laying mass year arrival arrival laying Observations

1955 — — _ June 2 1957 May 22 May 25 May 26 June 2 1958 June 10 June 13 much snow during winter, late spring 1959 — — - June I i960 — — May 31 June 6 1962 - - June 2 - 1963 May 21 May 25 May 30 June 3 1964 May 21 June 4 June 5 June 8 long late spring

Table ü. Variations in clutch-size with nesting density of Lesser Snow Geese on Wrangel Island, 1964

no. of maximum average nests no. of eggs no. of eggs nesting site areas examined in nest in nest

Low nesting density (up to 20 pairs per hectare) 133 5 3-18 Average nesting density (20-50 pairs per hectare) 190 6 3-24 High nesting density (50-100 pairs per hectare) 322 7 3-55 Total 645 3-27

Table HI. Nest occupancy and nest density of Lesser Snow Geese on Wrangel Island, 1964

no. of no. of percentage occupied unoccupied nests of nests nesting site areas nests discovered unoccupied

Low nesting density 133 44 24-8 Average nesting density 190 32 14-4 High nesting density 322 20 5'8

Total for nesting site 645 96 12-9

Table IV. Total number of nests of Lesser Snow Geese on Wrangel Island in use in June, 1964

average no. total no. of total area of nests occupied nesting site areas (hectares) per hectare nests

Low nesting density 1,200 12 14,400 Average nesting density 1,900 36 59,400 High nesting density 600 64 38,400

Total for nesting site 3,700 1 14,200

GEESE OF WRANGEL ISLAND I27 gonads, was shown by the results of dissec­ Eiders Somateria mollissima v-nigra near tion and by the fact that many nests were the nests of Snowy . The Arctic Fox not used by the birds (although the geese is the main cause of loss of eggs, and this occupy the last year’s nests first). It was was apparently the reason for the forma­ typical that non-breeding individuals tion of the two types of nesting site. In the reached the highest percentage in areas first case the safety of the eggs is in some where the snow was late in melting and measure assured by the relatively effective nesting density was at its lowest (Table III). collective self-defence measures adopted We have intentionally dwelt on some by the birds; observations show (we have details of the effect of weather conditions no large-scale figures) that predators do on goose breeding rates, taking the view most damage to pairs nesting on the edges that these facts throw some light on an of the colony or in its sparsely populated interesting but little studied phenomenon areas. The birds in the nucleus of the - ‘arctic failure to nest’ in birds. colony suffer practically no loss from According to the periods at which the predators. The small separate nesting sites eggs were laid, the first goslings appeared (in 1964, breeding on these sites was even in the nests of these geese on ist-2nd July, less successful) can exist only because of 1964. The colony began to break up on the energetic defence of their own and the 3rd-4th, and the mass departure occurred goose nests by Snowy Owls. on 6th-8th; the colony was practically It was stated above that nesting density deserted by 10th July, although individual in the main colony fluctuates within very late broods were still being encountered wide limits. It depends both on relief and here on I4th-I5th. According to surveys exposure, which determine when the snow carried on 7th-8th July, the average num­ melts, and on the condition of the grass. ber of goslings per brood (based on 33 Throughout the incubation period the families) was 2-7, varying from I to 5. birds feed only in their own nesting areas Birds which have not bred finish their moult (among the plants eaten by them are several and start to leave the island during the species of grass. Equisetum and the green first ten days of August, whereas the birds parts of creeping willow). Thus the dimen­ which have bred and the young of the year sions of these areas are directly determined start to leave during the second ten days by the state of the grazing, by the supply of August. The departure of the birds of plant life. usually ends between 20th and 30th August. The large-scale ringing of these geese, In 1964 we were able to conduct a more both on Wrangel Island (where it started careful survey of the birds in the main in i960) and in North America has given a colony. It was carried out (by marking out fairly complete picture of the migration 50 test areas o f 0-25 hectares each, evenly routes and wintering grounds of this distributed over the nesting site) immedi­ population. In particular it is clear that the ately after the birds had finished laying main wintering grounds are in northern (I5th-20th June) and gave the results California, the Willows and Tule Lake shown in Table IV. National Parks ; data on ringing this species In addition to surveying the nests, a have been analysed by T. P. Shevareva continuous visual count was made during (1959, 1961). this period of the birds on the nesting site. The second species of goose inhabiting Their numbers were assessed at 300,000 the island is the Brent Goose Branta (150,000-160,000 pairs), so the results of bernicla orientalis. It was known previously surveying the nests and of counting the that these birds nested here, but in much geese themselves more or less coincided. smaller numbers than A.caerulescens (for A wildlife reserve was set up on Wrangel example, L. A. Portenko mentioned it in Island in i960, to protect the nesting sites 1937)- In !9Ö4 large numbers of unmated, of the geese (and the Polar Bears, large mousing Brent Geese were discovered, numbers of which make their dens here). which had not been observed previously. Since then, collection of goose eggs and The birds nest, in single pairs and small other forms of exploitation have ceased, colonies, in many parts of the island, and this has undoubtedly contributed to principally in the large river valleys. The the increase in the birds’ numbers. This is Brent nests are either in colonies of clearly shown by a comparison of our i960 A.caerulescens or close to Snowy Owl nests. and 1964 survey results (especially when The birds’ selection of nesting ground of a one remembers that some of the birds did suitable colour is particularly striking. The not nest in 1964). nests are usually made on bare black or The second type of nesting site used by dark brown patches of earth or lichen. The A.c.caerulescens on the island is the small bird itself, and in its absence the nest, separate colony, or even single pairs, which thickly lined with dark brown down, are sometimes nest with Brent Geese and thus very well camouflaged. The times of

128 THE WILDFOWL TRUST migratory arrival and commencement of Brent Geese were caught in one flock; all laying are several days later than in the had been ringed in Alaska (Lower Kachu- case o f A.caerulescens. A fairly detailed nuk River), two males (1963) being marked survey of the island shows that the total as sub-adult, one male (1962) marked as number of Brent Geese nesting there in adult and another bird, also ringed in 1962 1964 was at best 1,000-2,000 pairs. without indication of age or sex. Judging We found gatherings of unmated Brent by the dates of ringing (nth July-5th Geese in mid-July, in the intensive moult­ August), they had also been caught in ing period. During this period they con­ Alaska during the moult. These finds are gregated in flocks of several hundred birds interesting for a number of reasons, al­ on the shores of shallow lakes in the flat though the data are insufficient for final tundra in the northern part of the island. conclusions. Among them were birds of at least two The total number of moulting, unmated age-groups, judging by the plumage. It Brent Geese could be approximately should be mentioned that four ringed assessed at not less than 10,000 birds. References

P o r t e n k o , L. A. 1937- Birds of Wrangel Island. Problemy Arktiki, No. 3 . m i n e e v , A. I. 1945. Wrangel Island. Moscow - Leningrad. u s p e n s k i i , s. M. 1963. Chen caerulescens caerulescens. Priroda No. 9. shevareva, T. P. 1959- Data on migration of wildfowl nesting in the northern U.S.S.R. Sym­ posium Animal Migration, published by the U.S.S.R. Academy of Sciences, Moscow. SHEVAREVA, T . P . 1 9 6 1 . Migration of Ch. caerulescens caerulescens. Ringing and marking of animals. Information bulletin No. 1, Nature Conservancy Commission, U.S.S.R. Academy of Sciences, Moscow.

th e Im p e r ial D u ck D ec o yShinhama - the Imperial Duck DecoyShinhama PETER SCOTT The Japanese duck decoy or Kamoba was The rough track through the rice and evolved from the European type during lotus fields passed a tidal creek full of the 19th century. The major difference is small boats and ended at a pair of large that in the Japanese form the ducks are gates. A short drive of grey gravel led to an caught individually with a hand net, which attractive reed thatched house - the head­ is regarded as a sporting activity and a quarters of the decoy. Here we were met social occasion. by the decoyman, a cheerful smiling man Two such decoys are maintained by the who offered us tea on a beautiful lawn Imperial Household, one on fresh, the overlooking a brackish pool of perhaps other on brackish water. On a bright sunny three or four acres fringed with bamboos. day in October 1964 my wife and I were This was outside the decoy and empty of privileged to visit the brackish pool at ducks. The only signs of life on it were Shinhama in company with Mr. Dudley some large fish which frequently jumped. Cheke - the British Minister - and Mrs. Along the lawn was a row of artificially Cheke. The Kamoba lies just across the stunted pine trees completing a delightful river Edo from Tokyo, no more than half Japanese scene. The decoyman brought out an hour from the city, in a large area of and demonstrated one of the hand nets which paddy fields, and adjacent to the estuary are the basis of the duck catching method- mudflats. It was mid-morning as we a rather large ‘butterfly net’ which was approached but nevertheless there were very light and beautifully balanced. springs of Teal and parties of Pintail and Briefly the principle of the Kamoba is Shoveler flighting across the rice fields and that, as in European decoys, the ducks are the reedy pools surrounding the decoy perennially undisturbed on a quiet pool, wood. As we stopped the car to watch surrounded by dense thicket. In this case them we could hear the loud quacking of additional attractions are a supply of what were evidently, from the nature of millet seed, and the continuous quacking the sound, a great many ‘farmyard ducks’. of 200 large ‘farmyard’ ducks. Radiating We could also see large numbers of herons from the pool (or tamari) are a number of and egrets sitting in the tops of the trees narrow vertical-sided ditches (hikibori) surrounding the decoy. There turned out about 5 feet wide and 25 yards long, which to be six species of these: Grey and bend sharply where they leave the pond Night Herons just like our own and four and pass through the bamboo thicket. The species of white ones - Great White, rest o f the hikibori is straight with a grassy Plumed, Little and Cattle Egrets. space on either side and across the end of

IMPERIAL DUCK DECOY 129 each is an observation hut (konozoki) with more than 70 or 80 - do not come to a ‘tube’ down which millet seed is rolled to Shinhama, perhaps because the water is lead the ducks on. The catchers, who in brackish. the Imperial decoys are for the most part In the middle of the tamari are two distinguished politicians and diplomats, square artificial islands called Nakajima assemble behind a bank and when the which were covered with cormorants, decoyman decides that enough ducks are egrets, Night Herons and Shovelers. Teal in, they are deployed, each with a ‘butterfly were crowded on the steep banks between net’, on both sides of the little channel. At the pipes. From the onozoki we were a given signal they run in and catch the looking down on Teal and Shovelers not ducks as they rise (or, quite often, we are more than 10 feet away. A bin in the corner told, each other). This much of the method of the hut contained millet and if some of we knew before the decoyman led us along this was poured down the little wooden a grass patch flanked by a 25 foot bamboo tube (made of three boards and triangular ‘wall’, through a gate, and across a cause­ in section) the decoy ducks came at once to way into the Kamoba itself. eat it, and so did Teal and Shovelers, pick­ Our first view was along an external, ing it up as it drifted away on the surface. rectangular, partly-reed-grown pool which During our two hours in the decoy there constituted the buffer area between the were several large movements of ducks, outer belt of trees and the ‘pipes’. A few mostly into the decoy, but once from one Teal and Pintails rose and flew over into end o f the tamari to the other. the tamari. The trees were full of egrets. Several times during the morning a The broad straight path we took was small group of 23 White-fronted Geese separated by a tall hedge from the buffer flew over the decoy - just the same White­ pool on our left. On our right was the first fronts as we see at Slimbridge, where the konozoki - the little concrete observation first 25 had arrived immediately before our hut, camouflaged in a grass-covered bank, departure for Japan. which commanded a view down the first of Towards the end of our time in the a row of eight pipes which flank the decoy we could hear great quackings from north-west side of the main pool. Through the tame decoy ducks. This was feeding the peephole we could see a few of the time. An assistant decoyman was pouring enormous piebald tame ducks which act as millet down the tube from one of the decoys. At the third konozoki a five foot onozoki huts to the accompaniment of loud yellowish-brown rat snake moved into the hammering with a wooden mallet on a open-backed hut ahead of us. It was at first special wooden block in the hut. cornered and could have been caught, but The noise was evidently a feeding signal just as I had decided it was non-poisonous to which the ducks were well used. It was and was about to pick it up, it found a so loud that when I entered the hut to see mouse hole in one comer and was down the reaction of the wild birds through the it and gone in two seconds. peephole, I was forced to block my ears - Half way along the north-west side of yet the wild Teal and Shovelers were the decoy was a different kind of observa­ crowded round the hut, the nearest less tion hut, called an onozoki, one o f six which than 10 feet away from the source of this stand at the very edge of the tamari giving shattering sound. a view through peepholes over the open Perhaps more remarkable was the fact water of the decoy. The whole rectangular that the decoyman and his assistant con­ pond seemed to be rather less than 300 versed in a loud voice during and after the yards long and about 100 yards across - hammering, and seemed only to attract the perhaps six acres in all - and had some wild ducks by doing so. When we left 6,000 ducks on it, mostly Common Teal the onozoki there must have been 500 birds with a number of Shoveler, a sprinkling of clustered around us within 20 or 30 yards. Pintails and a very few Garganey - perhaps The decoyman’s estimate of the num­ 50 all told. In spite of a careful search bers on the decoy was about the same as through the tiny peepholes, poorly suited mine - about 6,000 - but he said that on to binoculars, we were unable to find any some days later in the winter he believed Baikal Teal or Falcated Ducks. Nor, sur­ there might be 20,000. T h e annual catch prisingly, were there any Chinese Spotbills during recent years had been about 3,000 which were common on the Imperial birds, the great majority Teal. Palace Moat in Tokyo, though we later We feel greatly honoured to have been saw a small bunch flying outside the decoy allowed to see his interesting place and we over what must have been the shore. There are especially grateful to Air. Kikkawa of also we saw a small flock of Wigeon. Man­ the Imperial Household for making the darins, which later arrive on the Imperial arrangements and for sending on the Moat — though not apparently nowadays details of duck catches (Table I).

I 3° THE WILDFOWL TRUST Table I. The numbers of ducks taken in the Japanese Imperial DuckDecoys 1947-64 Hunting Saitama Preserve Shinhama Preserve Season* Other Other Grand Mallard Teal Ducks Total Mallard Teal Ducks Total Total 1947-48 2630 1035 32 3697 797 1756 75 2628 6325 1948-49 3554 1479 146 5179 517 2985 51 3553 8732 1949-50 1320 1527 232 3079 411 3803 191 4405 7484 1950-51 1609 1377 67 3053 386 3154 130 3670 6723 1951-52 1208 2043 223 3474 209 2293 91 2593 6067 1952-53 2044 1919 246 4209 549 3266 91 3906 8115 1953-54 1686 1529 108 3323 474 1873 124 2471 5794 1954-55 1396 1844 354 3594 254 2712 35 3001 6595 1955-56 1343 2488 234 4065 239 3551 157 3947 8012 1956-57 1761 1707 91 3559 374 3839 51 4264 7823 1957-58 2331 1080 84 3495 334 4256 162 4752 8247 1958-59 2167 1081 64 3312 273 2980 170 3423 6735 1959-60 1982 1211 83 3276 237 2075 201 2513 5789 1960-61 2650 700 280 3630 258 2216 418 2892 6522 1961-62 1671 899 225 2795 165 2500 151 2816 5611 1962-63 1883 747 172 2802 181 2844 136 3161 5963 1963-64 956 547 170 1673 97 2062 128 2287 3960 * From 1947-48 to 1952-53 the season lasted from 1 November to 28 February; from 1953-54 to 1963-64 it lasted from 1 November to 15 March.

Book Reviews

It is not a regular policy to publish book his way past puce passages with which even reviews with the Annual Report. However, the soberest experts seem constrained to a number of important publications have open their chapters. When he gets to the recently emerged, bearing on wildfowl meat it is wholesome and enormously conservation and/or closely associated with informative. A hundred leading researchers the Trust and its personnel. We therefore and conservationists have been mobilised feel it is not out of place to draw attention to survey every aspect of the subject. to them. We would also remind members In eleven logical chapters the wildfowl that orders placed through our Shop production areas of the North American benefit the Trust financially. continent are described and their import­ ance to the general picture and to the Waterfowl Tomorrow. Ed. Joseph P. individual species assessed. The wealth of Linduska. pp. xii + 770, many photo­ detail available to the conservation planners graphs and line drawings. U.S. Depart­ contrasts starkly with our near complete ment of the Interior, Washington. ignorance in Europe. We do not even know 1964. $4.00. if there is the equivalent of the prairie Many people interested in wildfowl know pot-holes and marshes, producing greatly that a great research and conservation varying numbers of ducks according to the effort has been directed to ensuring the rainfall trends, or whether we depend on survival of worthwhile numbers of these low density but more stable production birds in North America. Yet the depth and areas similar to the northern forests and detail of this massive programme has been tundra. apparent only to the specialist, for, as the Next are described the four ‘flyways’, Preface says, ‘most of the pertinent litera­ Atlantic, Mississipi, Central and Pacific, ture is not generally available in libraries’. and the wintering grounds in which they This book performs an extremely import­ terminate, including Mexico. The natural, ant function in making this knowledge, biological flyways overlap and vary, so fixed albeit of necessity in outline, available to administrative flyways, generally agreeing all - and at a remarkably low price. with the biological ones, are used as the The sensitive reader must suppress his basis for waterfowl management by regula­ shudders at some of the gay little chapter tion of season length and bag limit. Such headings such as ‘Cousins by the Dozens’, a system could well be adopted in Europe. ‘Talon and Fang’, ‘They also serve’, ‘Carp, Again it is astonishing how much is known a sometimes villain’. He must also force about the amount of habitat that is available

IMPERIAL DUCK DECOY 131 to wildfowl. For each State the area of high- ‘If enough citizens believe that the per­ value wetlands and permanent water is petuation of waterfowl is important, the known to within a thousand acres. In Europe job will be done. It is not too late.’ we have only just completed a simple Looking at the contemporary European list (Projet MAR) of important wetlands - scene one might well despair. We have such and this is certainly far from complete. a terribly long way to go in terms of public The book now turns to consideration of appreciation and international co-opera- the natural controlling factors; those of tion even to approach present American glacial history, water, weather, plant standards. But this book will help if it can succession, traditional behaviour; of the reach a wide European readership, making influence of muskrats, beavers and pre­ them aware just how piffling many of our dators; of diseases, parasites and lethal present efforts are and spurring everyone to algae. Then is considered the biggest the efforts and sacrifices that must be made perturbative factor of all, Man himself. if great flights of wildfowl are not to be a Some of his activities, as in draining for thing of the past. agriculture, are inimical, others, as in Proceedings of the First European building reservoirs and ponds, are inci­ Meeting on Wildfowl Conservation. dentally beneficial. The products of agri­ St. Andrews, Scotland, 16-18th October, culture itself are shown to provide a rich 1963. Ed. J. Swift, pp. 289.14black-and- living to those birds adaptable enough to white photographic plates, 28 text take advantage of them. But we return to figures. H.M. Stationery Office. £1.4.0. the inimical in chapters on pesticides, (obtainable from the Nature Conser­ water pollution, and lead poisoning from vancy, 19 Belgrave Square, London, spent shot. S.W .I., 25/- post free) The establishment of Federal, State and private refuges is described in historical As part of the growing tide of international detail. Their management and the way in co-operation the Nature Conservancy and which they are made to provide both the International Wildfowl Research Bu­ sanctuary for the birds and places where reau convened a gathering of 72 research they may be shot is also expounded clearly. biologists, naturalists, wildfowlers and The more intractable long-term problem administrators, representing 17 different of ensuring the continued existence of the countries and a number of international breeding grounds is stressed. organisations. This meeting was ‘the first Some of the most fascinating chapters to have before it a reasonably comprehen­ are those which describe the ways in which sive and authoritative picture of the wild­ Man can manipulate habitat to suit wild­ fowl situation in Europe, on the three vital fowl. Controlled flooding can result in levels of scientific data about wildfowl fantastic congregations of waterfowl, more movements and ecology; information about than a million duck (perhaps as many as we the use of the wildfowl resource for food, ever now have in Great Britain) on 2,000 sport, amenity, scientific and other pur­ acres in one instance. Knowledge of the poses; and a review of the existing legal chemistry of marshland ecology is increas­ and administrative status of European ing and much progress has been made in wildfowl’. the art of planting suitable vegetation and These vital data are made generally discouraging other forms. In America the available in this publication, together with lavish technique of growing farm crops for a record of the discussions and resolutions. waterfowl has produced spectacular results. Anyone with a serious interest in wildfowl T hus a 100 acre field o f maize fed 85,000 should have a copy for reference. ducks and 15,000 geese for a week. Even a The Trust played a considerable part in like area of oak woods, flooded temporarily, preparing the conference and in the editing not uncommonly supports 25,000 Mallard. of these papers to publication, as well as All this may seem dream-like to us, providing those on ‘The wildfowl situation cramped as we are b y lack o f birds and lack in England, Scotland and Wales’; ‘The of money. But it does show what can be present status of the Brent Goose in done by determined men who are not Europe’; ‘A summary of the known unwilling to pay for their pleasures. European situation, with suggestions for Two thoughtful chapters setting out the future work” ; and ‘Adverse and beneficial reasons for research and the ways in which developments affecting wildfowl in Great hunting regulations are decided upon each Britain’. season conclude the factual part of the A New Dictionary of Birds. Edited by book. The future outlook for wildfowl and Sir Landsborough Thomson, pp. 928, their hunters in North America is then 16 coloured plates, 32 photographic discussed, the key to the whole problem plates, many text figures. Nelson, being in the words that end the last chapter, London, 1964. £5.5.0.

132 THE WILDFOWL TRUST It is an understatement to call this stagger­ birds ; Homing Pigeon ; Navigation ; Swim­ ing volume a Dictionary (in deference to ming and Diving; Time Measurement; that of Newton, which it superbly super­ Wildfowl. sedes), containing as it does well over four Although rather awkward to handle in hundred major articles of encyclopaedic bed this book is one to dip into for length, ranging up to seven thousand words odd delight as well as for cold factual apiece. It is even more of an understate­ information. Read, for instance, of the ment for Sir Landsborough to be desig­ ‘Emu War’ from which a ‘crestfallen field nated simply as Editor. The whole enter­ force [7th Heavy Battery, Royal Australian prise is his from the initial choice of Artillery] .. . withdrew from the combat headings. He it was who coerced more than area after about a month’. two hundred authorities into providing Ornithology has received many services articles on their special subjects. He wrote from Sir Landsborough, culminating in innumerable linking sections and was this great work. And she has been placed responsible for the intricate cross-refer­ further in his debt by his arranging that ences. Not content with that, he produced the British Ornithologists’ Union, who full-length articles on Accentor; Aves; commissioned it as part of their Centenary Bee-eater; Classification; Cormorant; celebrations, shall receive all the royalties. Crow; Cuckoo; Darter; Distribution; These will be paid into a special fund that Flightlessness; Gannet; Gull; Hammer­ will be used to support further research head; Heron; Hoopoe; Hybridization; and special publications. Ibis; Kingfisher; Locomotion; Migration; Name, English; Nomenclature; Numbers; The World of Birds. A comprehensive Ornithology; Passeriformes ; Pelican; guide to general ornithology. James Plover; Range Expansion; Rhythm; Rol­ Fisher and Roger T ory Peterson, pp. 288. ler; Sandpiper; Senses; Sexual Dimor­ Coloured lithographs of 668 spp., 200 phism; ; Size; Species; Spoonbill; maps, many half-tone illustrations. Mac­ Swallow; Tameness; Young Bird. Few donald, London. 1964. £5.5.0. men today could have competence over The first third of this handsome book is a such a wide spectrum of ornithology. tour de force which leaves the viewer This is not simply an erudite work of breathless. Throughout ninety-five pages reference; though that is its raison d’etre the vigorous, colourful, faithful paintings and why no ornithological library will now coruscate, constantly startling by the be complete without it. Sixteen beautiful originality of posture, by the ingenuity and colour plates embellish and functionally artistry of their positioning, by their illustrate the text. They are contributed relevance to the text - a text which whips by eight artists (Peter Scott has one on us from facet to facet of bird biology and King Eiders) which in itself makes possible evolution. One stands in awe as intricate some fascinating comparisons of style. subjects like population studies and Further, there are more than two hundred instinct are audaciously thumb-nailed into text figures, mostly from the talented pen a few hundred crisp words, yet always with of Chloë Talbot Kelly (who also contri­ high regard for the selected facts. buted five colour plates). Lastly, there are Following such a stimulating eruption sixty-eight superlative black-and-white of interwoven talents, two chapters on photographs whose very excellence be­ Bird Watching and on Birds and Man, speaks the mass of material from which taking up a third of the book, seem rather these faultless selections were made. grey and less original. Nevertheless there It would be pointless to try and assess are informative discussions on the study the merits of the different articles. Coming of migration and of behaviour, on the from many contributors they vary in history of bird sanctuaries, on commercial clarity, readability and succinctness. There utilisation, sport, birds in conflict with will be disagreement with some of the Man and, finally, detailed lists of threat­ selections made or with the extent of ened and recently extinct birds. cross-referencing. But taken as a whole, The remaining third is certainly colour­ this book is a triumph, and unique. To be ful and original again. Maps, mostly of associated with it in any way is a matter of global coverage, display the distribution pride. Sir Landsborough has, of course, of families of living birds and of sites where been the Chairman of our Scientific fossil ones have been found. These maps Advisory Committee since its inception are elegantly and clearly composed and and it is gratifying to see that members of must represent a vast deal of painstaking that Committee have contributed a further research. Their value to the specialist in fifty-four major articles. From the pens at avian Systematics should be great. For the Slimbridge itself derive those on Count; general reader, at whom the rest of the Decoy; Duck; Food Selection; Game­ book appears to be aimed, the purpose of

EOOK REVIEWS 133 these maps is much less clear, particularly b i r d - b a n d i n g (U.S.A.). ... a compre­ as no interpretations are offered as to their hensive survey of England’s waterfowl zoogeographical interest. resources, the first ever made for any part Certainly this is a book which has some­ of Europe. The book is handsomely thing to please everyone. Perhaps one is produced, nicely proofed and printed and just being greedy in wishing that the first beautifully illustrated . . . presents a most brilliant section had been expanded at the graphic assessment of the status of water­ expense of the remainder. fowl in the British Isles today, and should On every copy that is sold a royalty is assist greatly in their preservation. being paid by the publishers to the World b i r d n o t e s . There are 368 pages of text Wildlife Fund. in this book and not one of them wasted. It is a classic - a milestone from which one Know Your Wildfowl Food Plants. can measure populations of wildfowl, the pp. 32. Published by the Wildfowlers’ progress of the Wildfowl Counts, manage­ Association of Great Britain and Ireland. 1964. Produced jointly by W.A.G.B.I. ment techniques and so on. It will be an and the Wildfowl Trust. (Obtainable important reference book for many years to come. from either organisation, 2/6d. incl. post and packing) b r i t i s h b i r d s . ... however much one This little pamphlet is in itself further may lament the gaps, they are in fact evidence of the growing co-operation surprisingly few and it is astonishing how between sporting and conservation interests much information has been collected .. . In such a monumental task there is little in Britain. Its aim is to provide sketches to cavil at and few books can be better (27) of the main food plants as an identifi­ cation aid to those who have the desire and value. opportunity to improve wetland areas by i b i s . This magnificent book . . . estab­ judicious planting and control programmes. lishes this country’s lead in European For each plant there is a short description wildfowl conservation, for no country has of the usual habitat, the flowering season, assembled such a mass of data, involving the seed sizes and the range of seed colour. an unprecedented co-ordination of amateur The species of wildfowl known to feed on effort over the past 14 years; nor is there the plant are also shown. Its preparation such excellent co-operation between wild­ was undertaken by Mr. Peter Olney. fowlers and conservationists, which is reflected throughout this book ... The Wildfowl in Great Britain. A survey of whole team, under the guiding influence the winter distribution of the Anatidae of the Director-General of the Nature and their conservation in England, Conservancy, is to be congratulated on a Scotland and Wales. Prepared by the first-class effort. The book should stimulate Wildfowl Trust, edited by G. L. Atkin­ all wildfowl-counters to continue their son-Willes and illustrated by Peter work with undiminished zeal, for it marks Scott, pp. xiv + 368 14 colour plates, a fine beginning to a task without end. 28 photographs, 5 text figures, 61 maps. JOURNAL OF ANIMAL ECOLOGY. T h e (Monographs of the Nature Conservancy results of the survey are well presented and No. 3). London. H.M. Stationery Office. it is particularly pleasing to find few errors 1963. in a work of this size and which has been Our monograph was published at the end based upon a very large number of counts of 1963 and only received passing mention (55,000 reports). The reviewer agrees with in the 15th Annual Report. It marks such Mr. E. M. Nicholson who, in the Fore­ an important stage in the development of word, states that ‘this production reflects our research programme, however, that we credit on all concerned .. .’ The Nature feel justified in giving it more formal Conservancy have set a high standard in notice now. It is hardly our place to their monograph series and this book can enlarge on its merits ourselves, so we have do no other than enhance their reputation modestly selected, from the dozen reviews and that of the Wildfowl Trust. that have come our way, some statements n a t u r e . The monograph is well pro­ of other people’s opinions: duced, with numerous maps, diagrams and a l a u d a . Le travail constituí une base relevant photographs. It is also pleasantly remarquable pour l’etude de l’évolution decorated with drawings by Mr. Peter des Anatidés en ce qui conserne leur Scott .. . and his previously published population et leur importance au point de colour plates of all the species are also vue de la chasse. included. This enterprise in ‘quantitative a r d e o l a . Fruto de persistentes estudios ornithology’ was well worth undertaking cuantitativos sobre Anatidas que se vinieron and its outcome deserved such handsome realizando en Gran Bretaña. presentation.

134 THE WILDFOWL TRUST Sc o t t i s h b i r d s . The mass of accumu­ knowledge of the Anatidae, and a valuable lated data must be enormous, and that it is pointer how best such a wonderful heritage presented in such readable form is a can be conserved. The book is beautifully tribute to the editor ... The quality of produced by H.M. Stationery Office and is this book and the amount of information it furnished with two serviceable indexes. contains, gives it a deserved place on the d i e VOGELWARTE. Grossartige Darstel­ bookshelf of every ornithologist, conserva­ lung und prächtige Ausstattung des Buches tionist and wildfowler alike. entsprechen der Anstrengung, Passion und t e r r e e t v i e . . . . ime pléiade d’ornitho­ Gründlicheit der britischen Entenvogel­ logistes professionnels et amateurs se zähler; sie stehen aber auch im Einklang penchent sur l’étude du statut hivernal des mit den einmaligen Entenvogel-Lands­ Ansériformes en Grande Bretagne ... chaften dieses Inselreiches. Der Verf, hat Leurs efforts viennent d’être récompensés hier mit umfassender Kenntnis, mit par le travail remarquable de l’éditeur et grosster Liebe zur Sache und mit ausseror­ de ses collègues du W ildfowl T ru st sous la dentlicher Klarheit der Darstellung einen forme de cette magistrale monographie. ‘Klassiker’ geschaffen, der für die gesamte europäische Vasservogelforschung - im t i m e s l i t e r a r y s u p p l e m e n t . This hand­ some volume ... fully upholds the high Dienste der Erhaltung der Anatiden - standard we have come to expect from the Markstein und Ansporn zugleich werden Nature Conservancy ... Part II ... is by dürfte. far the most important section of the book We are informed that the first printing and is accompanied by beautifully clear o f 3,000 has been sold out, a most unusual maps of the areas under discussion. It is fate for a specialised monograph. However, thus easy to refer to any part of the country a second printing has been made and without wading through a mass of irrele­ copies may be obtained from the Trust at vant matter. The whole work has been well the published price plus 2/6d. post and edited ... a first-rate contribution to packing.

BOOK REVIEWS 135 Section 3

Photographs

The Trust is greatly indebted to the persons and agencies named below for permission to reproduce their photographs :

The Japanese Imperial Household F. Bailey & Son, Ltd. Bristol Evening Post F. B. Chernyavskogo Morley Hedley Paul A. Johnsgard Russ Kinne N . Rajkov Philippa Scott S. M. Uspenski

The contributors retain the copyright of all the photographs.

136