THE MIGRATIONS OF BRITISH () AS SHOWN BY RINGING RESULTS* By A. LANDSBOROUGH THOMSON THE PURPOSE of this paper is to analyse the recovery of species of the Falconidae ringed in the British Isles under the scheme now managed by the -Ringing Committee of the British Trust for Ornithology and earlier by the late H, F, Witherby, then Editor of British . There were no recoveries for any of these species under the former Aberdeen University scheme. Another paper (Thomson, 1958) has already dealt with the hawks (Accipitridae). The numbers of each of the species concerned that have been ringed and recovered under the scheme are: — Ringed Recovered Percentage to 31.12.56 to $1.12.57 recovered Hobby 48 4 8.3 Peregrine 155 (22) 18 11.6 ... 532 (83) 80 15.0 Red-footed ... 1 — — ... 1,982 (255) 247 12.5 (The recovery figures shown in brackets are those counted before excluding certain records as non-viable, for reasons given later; the reduced totals are used in calculating the percentages.) *A publication of the British Trust for Ornithology, the Bird-Ringing Committee of which is indebted to the British Museum (Natural History) for accommodation and ring address and to the Nature Conservancy for financial support.

continued ...

179 180 BRITISH BIRDS [VOL. LI

Recoveries in the British Isles of birds ringed abroad are mentioned. Details have been published in the periodical lists in British Birds compiled at first by H. F. Witherby and E. P. Leach and latterly by E. P. Leach alone. Hobby (Falco subbuteo) Recoveries of birds ringed as nestlings. There are four records. Of 3 birds ringed in Wiltshire, one was recovered on 16th October of its first year, in Landes, France; one on 13th September of its first year, at Espinho, N. Portugal; and one in August of its second year, in Herefordshire, about 100 miles to the north. The fourth bird, ringed in Surrey, was recovered locally within a few weeks. British recovery of bird ringed abroad. One native to Uppsala, Sweden, was recovered in Norfolk in September of its first year. Peregrine (Falco peregrinus) Recoveries of birds ringed as nestlings. Excluding 4 birds found dead in the nest, there are 18 records. All these are of birds ringed as nestlings (counting one trapped as young on 5th July) in Great Britain (including one in the Isle of Man). The recovery localities can be grouped as follows: — (a) Local:— 6. (b) Distances of about 50 miles: — 4, the directions being northerly in 3 cases and south-westerly in the other (Cumberland to Isle of Man). (c) Distances of the order of 100 miles (actually 85-110): — 5, the directions being northerly in 4 cases (Banffshire to Ross- shire, Cumberland to Ayrshire, Selkirkshire to Kincardineshire, and Westmorland to Perthshire) and south-easterly in the other (Sutherland to Banffshire). (d) Distances of about 150 miles:— 2, the directions being N.W. and N. (Yorkshire to, respectively, Argyll and Fife). (e) A distance of over 400 miles:— 1, from Cape Wrath, Sutherland, to Co. Wexford, Eire, in January of its first year— about 420 miles in a direction slightly west of south. Only the last record, under (e), is suggestive of a real migration. The other distances are small for a bird with such great powers of flight; and northerly directions predominate in this series. No seasonal pattern is discernible, as both the local and distant records relate to all times of year: the Yorkshire bird recovered in Argyll, 152 miles N.W., was described as "shot at the nest"—in April of its fifth year. Nor is there an age pattern; some of the youngest and also the two oldest birds were recovered locally. VOL. LI] MIGRATIONS OF BRITISH FALCONS 181

6 of the recoveries were in April or May, 3 in August, 4 in October and the rest singly in other months. It is not possible to relate the distribution to reported causes of death, although two records resulted from shooting at the beginning of the breeding season. The age distribution, in years of life reckoned' from 1st April, is :— 5, 5, 2, 1, 3, o, o, 1, 1. The last two birds were, respectively, more than seven and (although in the ninth year by the conven­ tional reckoning) actually not quite eight years old. British recoveries of birds ringed abroad. There are 8 recovery records of birds ringed in the breeding season, mostly as young, in Scandinavia. Of those recovered in the first winter, 2 from the Lofoten Islands, N. Norway, had reached Berkshire and Lincolnshire respectively, one from Swedish Lapland had reached Gloucestershire, and one from Halland, S. Sweden, had reached Devon. The other displacements, recorded in subsequent winters, were from Vastergotland, S. Sweden, to Kent; from Vastmanland, Sweden, to Kent and to Yorkshire; and from Lulea, N. Sweden, to Shropshire (in its fifth year). Merlin (Falco columbarius) One local record is excluded for lack of a recovery date (in the first summer) and two others because of unnatural circumstances: one bird had been used for falconry subsequent to ringing and the other was ringed after a period of captivity. This leaves 80 recoveries, 69 of birds ringed as nestlings and 11 of birds ringed otherwise; all the ringing localities were in Great Britain. Recoveries of birds ringed as nestlings. The incidence of the 69 recoveries by season and age, years of life being reckoned from 1st April, is shown in the following table: —

Month Year of life Total First Second Third Fourth Fifth Sixth and over

April 3 2 5 May 2 3 S June 1 2 1 1 1 6 July 3 1 1 S August 9 1 1 11 September 4 2 1 -(7th) 7 October 6 1 2 1 10 November 1 1 1 3 December 3 2 S January 1 1 February 1 2 3 March 1 1 2 (6th; 8th) 4 Uncertain 2 2 4 Total 32 16 11 5 2 3 69 182 BRITISH BIRDS [VOL. LI

Only 3 were recovered abroad: — Month of recovery Native locality Recovery locality First year: October Yorkshire Landes, France November Devon Charente Maritime, France Sixth year: March Yorkshire Charente Maritime, France (A member of the same brood as the first of the above was recovered in Lancashire in its first December.) Of the 66 recoveries within Great Britain, 46 may be classed as local, being either from the ringing locality or from within a short distance (probably never as much as 40 miles, but in many instances exact ringing localities were suppressed for reasons of discretion). Of the remaining 20, only 8 were from distances of over 80 miles, as follows: — Recovery date Displacement (approx., in miles) First year: August Within Yorkshire (88 S.E.) August ...... Caithness—Aberdeenshire (100 S.E.) September S. Yorkshire—Berwick-upon-Tweed (165 N.N.W.) October Perthshire—Kirkcudbrightshire (90 S.) October Co. Durham—Dorset (270 S.) December ...... Yorkshire—-Shropshire (125 S.) Third year: May Yorkshire—Shropshire (112 S.) Fifth year: June Yorkshire—-Kirkcudbrightshire (96 N.W.) It will be seen that all but one of the first-year birds had taken southerly directions. The two records for subsequent summers may possibly indicate breeding displacement. Of the 7 first-year recoveries and 5 later recoveries from distances of between 40 and 80 miles, some are from northerly directions—including two rather over 40 miles from their nests in the first July and first August respectively. Recoveries of birds ringed when full-grown. There are 2 records of birds ringed otherwise than on migration and recovered locally; and the following 9 records of birds ringed while on migration off the Scottish coast and recovered later in the same season or, in one case, next spring. Ringing data 'Recovery data 9 12.8.56 Fair Isle 30.8.56 tair Isle 9 16.9.52 3.10.52 Caithness (100 miles S.W.) 6 'S-9-54 8.10.54 Landes, France juv. 9 18.8.54 9.10.54 Kincardineshire (170 S.S.W.) juv. 3-9-57 11.10.57 Bremerhaven, Germany juv. 0" 18.8.53 18.10.53 Liege, Belgium juv. 6 28.8.56 (20.10.56) Limburg, Belgium 6 19.8.52 17.12.52 Perthshire (220 S.S.W.) juv. 19.10.50 Isle of May 10.3.51 Kirkcudbrightshire (95 S.W.) VOL. LI] MIGRATIONS OF BRITISH FALCONS 183

British recoveries of birds ringed abroad. Three birds native to Iceland have been recovered in October- December of their first year, in Stirling-shire, Lancashire and Offaly, Eire; and another in April of its fourth year, in Dunbarton­ shire. (There is also a record of a bird native to Jamtland, Sweden, in its third winter, in Jersey, Channel Islands.) Kestrel (Falco tinnunculus) After excluding 8 records—in which four birds had never flown, two others were recovered locally at early but uncertain dates, one had been transported and was recovered on the day of release, and one (treated separately below) was ringed in the Channel Islands—there are 247 recoveries. Of these, 213 are of birds ringed as nestlings in the British Isles (mainly Great Britain) and 34 of birds ringed as full-grown. Recoveries of birds ringed as nestlings. The incidence of the recoveries by season and age, years of life being reckoned from 1st April, is shown in the following table: — Month Year of life Total First Second Third Fourth Fifth Sixth Seventh and over April 6 1 1 1 (7th) 9 May 6 2 S 1 (8th) '4 June 3 2 2 1 2 (9th; 12th) 10 July 12 4 1 1 18 August 2S 4 1 3° September 21 3 1 i 26 October 16 1 1 (9th) 18 November '4 1 1 1 17 December 11 4 IS January '7 4 1 1 2 25 February 12 2 1 1 2 18 March 6 2 8 Uncertain 1 3 1 5 Total 135 42 11 14 3 3 5 213 Of the above total, 146 birds were recovered locally or within distances of 50 miles; 49 were recovered at greater distances within the British Isles; and 18 were recovered abroad. One of the birds recovered, locally, in February of its fifth year had also been reported in June of its third (not in table for the earlier date). The oldest bird, 11 years of age, was recovered in June at a locality 76 miles N.N.E. The next three oldest birds (8|, 8 and 7 years) were recovered near their places of birth—the eight-year-old bird was breeding within 200 yards. The relatively large number of recoveries in April, May and June of the second and later years of life is noteworthy—as in the case of the Sparrowhawk [Accipiter nisus) (Thomson, 1958). Of the birds recovered in their first year at distances of 51-100 184 BRITISH BIRDS [VOL. LI

MAP I—FIRST-WINTER RECOVERIES OK (Falco tinnunculus) WITHIN THE BRITISH ISLES This shows the first-winter displacements (including one record in April of second year) exceeding ioo miles, but within the British Isles, of birds ringed as nestlings (details on page 185). Each spot indicates a recovery locality and the other end of the connecting line the corresponding ringing locality. For recoveries abroad, including those in later years, see Map 2 (page 186). VOL. LI] MIGRATIONS OF BRITISH FALCONS 185

miles, II had travelled in southerly directions, 10 in northerly directions and I eastwards; but of birds recovered in their first year (including the next spring) at greater distances within the British Isles—as listed below-—15 had travelled in southerly directions and only 1 in a northerly direction (150 miles). This indicates a random dispersal within a radius of up to 100 miles, but a definite migratory tendency in longer flights—of which the recoveries abroad give further evidence. The following list (see also Map 1) of 21 recoveries within the British Isles is limited to those showing movement (not necessarily complete at the earlier dates) of more than 100 miles: — Recovery date Displacement (approx., in miles) First year: July Anglesey—Dorset (185 S.S.E.) August Derbyshire—Sussex (140 S.S.E.) September Lincolnshire—Shropshire (140 S.W.) ,, Orkney—Sussex (560 S.S.E.) ,, Norfolk—-Herefordshire (135 W.S.W.) October Northumberland—Bedfordshire (250 S.S.E.) ,, Cambridgeshire—Hampshire (130 S.W.) ,, Orkney—Co. Durham (300 S.S.E.) „ Dumfriesshire—Sussex (330 S.S.E.) December ...... Dumfriesshire—Huntingdonshire (250 S.E.) ,, ...... Derbyshire—Sussex {140 S.S.E.) January ...... Northumberland—Inverness-shire (150 N.W.) ,, ...... Yorkshire—Sussex (220 S.S.E.) ,, ...... Yorkshire—Warwickshire (150 S.) February Dumfriesshire—Lancashire (115 S.S.E.) Second year: April ...... Cumberland—Co. Wexford, Eire (205 S.W.) December Yorkshire—Surrey (283 S.S.E.) March Northumberland—East Lothian (140 N.N.W.) Fourth year: June Lancashire—Norfolk (150 S.E.) Sixth year: April ...... Northumberland—Aberdeenshire (150 N.) Uncertain Derbyshire—Norfolk (130 E.) In the case of birds recovered after their first year it is obviously impossible to know what movements had taken place in the interval. The June record suggests displacement of breeding locality. The following is a complete list (see also Map 2) of recoveries abroad:— Month of recovery Native locality Recovery locality First vear: September (25th) Isle of Man Basses-Pyrenees, France October ... Yorkshire Sarthe, France ,, Yorkshire Eure-et-Loir, France ,, Lincolnshire Ostende, Belgium ,, ... .. Isle of Man E. Flanders, Belgium November Wiltshire ... Loiret, France ), .. Lancashire Vendee, France ,, Dumfriesshire Loir-et-Cher, France December Surrey Cortes, Navarra, Spain .1 Buckinghamshire Indre, France February Berkshire Nord, France March Essex Oise, France ,, Buckinghamshire Calvados, France 186 BRITISH BIRDS [VOL. LI

Second year: May ...... Bedfordshire ... Li&ge, Belgium June ...... Yorkshire ... Pas-de-Calais, France January ...... Lancashire ... Västergötland, Sweden March ...... Northumberland ... Nord, France Sixth year: January ...... Lincolnshire ... Eure, France

MAP 2—RECOVERIES ABROAD OF BRITISH-RINGED KESTRELS (Falco tinnunculus) The seventeen crosses mark the recovery localities abroad, mostly in the first winter, of birds ringed as nestlings in Great Britain and the Isle of Man. There is also an eighteenth record, not shown, of a bird ringed in Lancashire and recovered in its second winter in Västergötland, Sweden (see top of page). VOL. uj MIGRATIONS OF BRITISH FALCONS 187

The Swedish record seems abnormal: one may suppose that the bird migrated in its first autumn, made an aberrant return in spring and remained in its new summer area in its second winter. Recoveries of birds ringed when full-grown. Of the 34 birds in this category, 24 were recovered at or quite near the place of ringing in circumstances of no particular interest; the intervals ranged from days to 4J years. There are 4 other local records: one bird ringed as a juvenile on Skokholm, off Pembrokeshire, on nth April 1936 was recovered there on 17th August 1936 and again on 5th July 1937—probably a sedentary local bird; one ringed as a young bird in Middlesex on 13th July was recovered in Kent, 23 miles S.E., 13 days later; one ringed as an adult at Spurn Point, Yorkshire, on 14th September was recovered in the same county, 27 miles N.W., 19 days later; and one ringed in Essex in January was recovered in Norfolk, 40 miles N.N.E., in April of the following year. In 2 other British recoveries there was greater movement: a bird ringed at Spurn Point, Yorkshire, on 28th August was recovered in Cambridgeshire, 65 miles S., on 15th October of the same year; one ringed in Worcestershire in March was recovered on Caldey Island, off Pembrokeshire, in July of the second' year following. The remaining 4, ringed on (inferentially) autumn migration, were recovered abroad as follows : — Ringing data Recovery data ad. 9 27-9-53 Smith's Knoll Lightship (24J miles E. of Gt. Yarmouth) 13.to.53 Nord, France ad. 21.8.55 Dungeness, Kent 4.12.55 Charente, France juv. 27.10.53 Lundy Island, Bristol Channel 13.12.53 Finistere, France juv. 9 26.7.50 Fair Isle, Scotland 29.12.50 Loiret, France Recovery of a bird ringed outside the area. A bird ringed as "young" in July on Jersey, Channel Islands, was recovered in Maine-et-Loire, France, in November of the same year; this case is excluded from total figures. British recoveries of birds ringed abroad. There are four records of birds ringed on the Continent as nestlings—one from Schouwen, Holland, in East Lothian on 31st August of its first year; one from Valdres, S. Norway, in Co. Kerry, Eire, in October of its first year; one from Silesia in York­ shire in November of its second year; and one from Friesland, Holland, in Gloucestershire in January of its second 'year. One ringed on 30th September in S. Norway when full-grown was recovered on 19th December of the same year in Bedfordshire. One ringed as an adult in October at Antwerp, Belgium, was recovered in June of the third subsequent summer in Yorkshire (conceivably its native area). SUMMARY HOBBY.—Birds native to the south of England (Wiltshire) were 188 BRITISH BIRDS [VOL. LI recorded in their first autumn, from western France (Landes) and northern Portugal (Espinho), the latter as early as 13th September. A third was recorded in August of its second year, 100 miles north of its birthplace. A Swedish native bird has been recovered in Norfolk in its first autumn. PEREGRINE.—Birds native to Great Britain show a marked tendency to wander, up to distances of about 150 miles, and may breed in the localities thus reached. The directions are probably random, northerly ones in fact predominating in this small series. There is only one record of a longer movement—from N.W. Scot­ land to S.E, Ireland, about 420 miles, in its first winter. The oldest bird recovered had attained an age of nearly eight years. Scandinavian birds have been recorded in various parts of England in their first and subsequent winters. MERLIN.—Birds ringed as nestlings were recovered in the British Isles in all months of the year, the majority of them locally; of the few showing significant movement (up to 270 miles), the direction taken was southerly in most cases, but not in all; possible breeding displacement of the order of 100 miles was indicated in two cases. The only two foreign recoveries were from France in winter. The oldest bird was in its eighth year. Birds ringed on migration at Fair Isle in August and September were recovered, later in the same season, on the mainland of Scotland (one in mid-winter), in Belgium (2) and in France (1). Birds native to Iceland have been recovered in the British Isles in their first winter and in a later spring. KESTREL.—Many of the British birds are sedentary, as shown by local recoveries throughout the year and at all ages. At least in the first autumn there is random dispersal, within a radius of up to 100 miles, on the part of some. Others show a more definite tendency to southerly migration, but-—as shown by mid­ winter recoveries at distances of some hundreds of miles—not necessarily beyond the limits of Great Britain. There are, how­ ever, records of emigration to the Continent—Belgium (3), France (13), and N. Spain (1)—and one of a bird recovered in Sweden in its second winter. The oldest bird was eleven years of age. In addition, there are a few records of birds of unknown origin ringed on migration, both as juveniles and as adults, and recovered in France within the next few months. Birds native to Norway, Holland and Silesia have been recovered in the British Isles in their first or second winters. One ringed in Belgium in autumn has been recovered in Yorkshire in a subsequent summer.

REFERENCE

THOMSON, A. LANDSBOROUGH (1958): "The migrations of British hawks (Accipitridae) as shown by ringing results". Brit. Birds, H: 85-93.