The eighteenth Annual Report of The Wildfowl Trust Edited by Hugh Boyd, assisted by M. A. Ogilvie Illustrated by Peter Scott and Robert Gillmor Price 17/6d. ($3.10 postage paid) Printed for t h e w il d f o w l t r u s t b y t h e Be r k s h ir e p r in t in g C o. l t d ., Reading, Berks., England, 1967 The Wildfowl Trust Patron h e r m a j e s t y t h e q u e e n President His Grace the Duke of Norfolk, K .G ., p .c ., g .c .v .o . Vice-Presidents Captain R. G. W. Berkeley The Rt. Hon. The Lord Howick of 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, Kt. Sir Isaac Wolfson, Bt., F.R .S., f .r .c .p ., d .c .l . Trustees His Grace the Duke of Beaufort. K.G.. p.c.. g .c .v .o . The Earl of Mansfield, j . p . John Berkeley, Esq., j .p . H. H. Davis, Esq. Hon. Treasurer Guy Benson, Esq. Hon. Director Peter Scott, Esq., c .b .e ., d . s .C.: LL.D. Council G. R. Askew, Esq. Dr. G. W. Storey Elected Members Dr. Bruce Campbell Miss P. Talbot-Ponsonby J. O. Death, Esq. Sir Landsborough Thomson, Professor J. E. Harris, C.B., O.B.E., D.SC., LL.D. C.B.E., F.R.S. Major General C. B. G. A. J. Jamieson, Esq. Wainwright, c .b . K. Miller Jones, Esq. The Hon. Vincent Weir R. E. M. Pilcher, Esq., f .r .c .s . Co-opted Members Michael Crichton, Esq., o .b .e . G. M. Jolliffe, Esq., f .L.a .S. Captain J. A. Fergusson- Christopher Marier, Esq. Cunninghame J. P. Williams, Esq. Invited to attend Professor G M. Hughes Miss Emilie Davies, h .m .i . meetings ex-officio (Chairman of S.A.C.) (Ministry of Education Assessor) Finance Guy Benson (Chairman) G. A. J. Jamieson, Esq. Committee Michael Crichton, Esq., o .b .e . K. Miller Jones, Esq. J. O. Death, Esq. Miss P. Talbot-Ponsonby R. C. P. Hollond, Esq. Scientific Professor G. M. Hughes R. C. Homes, Esq. Advisory (Chairman) Sir Julian Huxley, f .r .s . Committee Professor A. J. Cain Dr. D. Lack, f .r .s . Dr. B. Campbell Professor C. W. Ottaway R. K. Cornwallis, Esq. R. E. M. Pilcher, Esq., f .r .c .s . Dr. H. D. Crofton Dr. G. W. Storey Dr. J. H. Crook Professor W. H. Thorpe, f .r .s . Dr. G. M. Durniet Major General C. B. Dr. J. G. Harrison Wain wright, c .b . Professor R. A. Hinde Professor E. W. Yemm Contents Annual Report 1965-66 r e p o r t . C. E. H. Sparrow Page 5 19t h a n n u a l g e n e r a l m e e t in g 8 THE c o l l e c t i o n s in 1966. S. T. Johnstone 10 conservation , education and research , 1966. G. V. T. Matthews 14 Wild geese at the New Grounds, 1965-66. M. A. Ogilvie 17 Ringing, 1965-66. M. A. Ogilvie 17 Borough Fen Decoy, 1966. W. A. Cook 20 Dersingham Decoy. J. E. A. Lambert and W. A. Cook 22 The Bewick’s Swans at Slimbridge, 1966-67. Dafila Scott 24 Year-book for 1966 Results of wildfowl ringing at Abberton Reservoir, Essex, 1949 to 1966. Major General C. B. Wainwright, C.B. 28 A survey of the ducks breeding at Loch Leven in 1966. H. Boyd and C. R. G. Campbell 36 The W.A.G.B.I.—Wildfowl Trust Experimental Reserve — the first eleven years Introduction. 43 Part I. Development of the wildfowl population. J. M. Harrison, J. G. Harrison and A. Meikle 44 Part II. The feeding ecology of local Mallard and other wildfowl. P. J. S. Olney 47 Part III. An appraisal of the planting programme, 1959-66. D. F. W. Pollard 55 Part IV. Expenditure for habitat improvement. A. Meikle 62 Population changes and mortality of the Mute Swan in Britain. M. A. Ogilvie 64 A preliminary study of the Mute Swan, Cygnus olor. C. M. Perrins and C. M. Reynolds 74 Immigrant Mute Swans in south-east England. J. G. Harrison and M. A. Ogilvie 85 Some parameters of “ nonsense” orientation in Mallard. G. V. T. Matthews 88 Observations on the behaviour and relationships of the White-backed Duck and the Stiff-tailed Ducks. P. A. Johnsgard 98 Breeding behaviour of captive Shovelers. F. McKinney 108 Experiments with young nidifugous birds on a visual cliff. Janet Kear 122 The significance of clutch-size in waterfowl. David Lack 125 Geese on the Hortobágy, autumn 1966. Jules Philippona and Tom Lebret 129 Observations on the Pink-footed Goose in central Iceland, 1966. D. E. Hardy 134 Food habits of sea ducks from the north-eastern United States. F. B. McGilvrey 142 Experience in waterfowl management under the conditions prevailing in the Latvian S.S.R. H. Mihelsons, J. Viksne and G. Lejins 146 Wildfowl survey in south-west Asia : progress in 1966. Christopher Savage 150 Short notes : Melanistic White-fronted and other Grey Geese. James Harrison, Jeffery Harrison and Michael Hudson 153 A bigamous Greylag gander. Jeffery Harrison 155 Drake Harlequin escorting its family. Jeffery Harrison 155 Techniques for rapid extraction of ingested food from wildfowl viscera. D. F. W. Pollard 156 Comparison of techniques for the analysis of wildfowl viscera. D. F. W. Pollard 158 Accounts for the year ended 31st December 1966 160 Balance sheet, 31st December 1966 162 Photographs 164 Annual Report 1 9 6 5 - 6 6 Report C. E. H. SPARROW Royal Visit The annual meeting of the Scientific Ad­ visory Committee was held in London on On 23rd April, 1966, the Trust was 24th March. honoured by a visit by its Patron, Her Majesty the Queen, who came to in­ augurate the Research Centre. She was Annual General Meeting and Dinner accompanied by His Royal Highness The Eighteenth Annual General Meeting Prince Philip, Duke of Edinburgh, and was held at the Royal Society of Arts on Their Royal Highnesses the Duke and 12th May and the Annual Dinner took Duchess of Kent. Her Majesty was wel­ place at the Hyde Park Hotel the same comed by the Hon. Director and after un­ evening. The President was in the chair veiling a plaque commemorating the occa­ at the A.G.M., and presided and spoke at sion was thanked by the President. She the Dinner. Other speakers at the Dinner then made a tour of the building and of were Mr. A. Dickson Wright, M.S., M.B., the grounds, and was entertained to F .R .C .S., Mr. Peter Scott, c .b .e ., d . s .c ., sherry in the Hon. Director’s house before L L .D ., and Lord Netherthorpe, i x .d ., B.SC. leaving. (See Photograph Section pp. I The minutes of the Annual General Meet­ and II.) ing will be found on page 8. Council and Committees Development The Officers, Council and Committees of the Trust, as at 31st December, 1966, In the autumn of 1966 work started on are shown on page 2. Meetings of the the construction of a Tropical Aviary at Council were held in London on 22nd Slimbridge with funds given by an anony­ February, 9th August and 13th December mous donor. Another development made and of the Finance Committee on 16th possible by a generous gift (from Mr. February, 26th July and 23rd November. Duncan Holden in memory of his father) 6 The Wildfowl Trust was a new observation tower, close to the R. Law, Miss E. Manasseh, E. A. Max­ sea wall with splendid views over the well, A. McLean, Mrs. B. Micheli, R. B. Dumbles and connected to the Rushy Moseley, G. Newman, F. W. Perowne, R. Pen by a screened corridor. (See Photo­ E. M. Pilcher, G. R. Pryor, P. Short, graph Section page X lower.) Shrewsbury School, E. O. Squire, Mrs. P. V. Upton, J. Williams, D. Wintle. Exhibitions Gosîing Party A permanent exhibition demonstrating the vital importance of conservation and of The annual Gosling Party was held at the constructive use of leisure in the Slimbridge on 23rd December, 1966. The world today and showing how the work Hon. Director showed the Trust film, of the Trust is related to these problems Wild Wings, to an appreciative audience was opened in the Research Centre on the of about 80. day of its inauguration. In National Nature Week the Trust had Staff a stand in the Observer Wildlife Exhibi­ tion at Alexandra Palace from 21st April It is with regret that the death on 20th to 1st May, and an educational display December, 1966, of Mr. E. A. Scholes, was mounted at the Daily Mail School­ who was Secretary of the Trust for over boys’ and Girls’ Exhibition at Olympia 17 years, is recorded. His place has been from 27th December, 1966, to 10th Jan­ taken by Lt.-Col. P. G. W. Coke. uary, 1967. The educational potential of the Trust was greatly increased during the year by the addition of an Educational Officer to Identification Competition the establishment. The post was filled in The Trust’s Fifth Wildfowl Identification September by Mr. E. E. Jackson. Competition for Schools was held at Slimbridge on 19th March, 1966. Leigh­ Finance ton Park again had a large and very suc­ cessful entry: their teams took the first A record number of visitors to both and second places in both Group A and Slimbridge and Peakirk (see table below) Group B, with Bristol Grammar School and several generous donations gave the third in Group A and Clifton College Trust its highest ever income in 1966.