WILDFOWL 19 Published by the Wildfowl Trust, Slimbridge as a continuation of the Wildfowl Trust Annual Reports, 1-18 1968 Editors: G. V. T. Matthews and M. A. Ogilvie The Wildfowl Trust, Slimbridge, Gloucestershire, England Cover painting by Peter Scott Line drawings by Peter Scott, Robert Gillmor and others Price 17/6d. ($2.50). Postage extra Issued free to Life and Full Members of the Wildfowl Trust Printed for th e w il d f o w l t r u s t by t h e Be r k s h ir e p r in t in g Co. LTD., Reading, Berkshire, England, 1968 Contents Editorial Page 4 The moult migration. Finn Salomonsen 5 Some field notes on the breeding of the Greater Kelp Goose. Peter Gladstone and Charles Martell 25 First breeding of the Magellanic Flightless Steamer Duck in captivity. John A. Griswold 32 Plumages and wing spurs of Torrent Ducks. Milton W. Weller 33 Pairing and breeding of Mute Swans. C. D. T. Minton 41 Inter-specific pairing in Scaup and Tufted Duck. Sven-Axel Bengtson 61 Nest-building movements performed by male ducks. F. McKinney 64 The proportion of yolk in the eggs of waterfowl. David Lack 67 The hatching and nest-exodus behaviour of Mallard. A. Bjärvall 70 Adoption of young by Versicolor Teal and other wildfowl. D. S. Wintle 81 Ecology of waterfowl in the region of Lake Neusiedl, Austria. Antal Festetics and Bernd Leisler 83 Barnacle Geese in the west of Scotland, 1957-67. H ugh Boyd 96 A preliminary study of the feeding ecology of the Greenland White-fronted Goose in Cardiganshire. D. F. W. Pollard and P. Walters-Davies 108 A trial to investigate the reactions of sheep to goose droppings on grass. J. B. A. Rochard and Janet Kear 117 The attempted rehabilitation of oiled sea birds. J. V. Beer 120 The Slimbridge collection — the first 21 years. 5. T. Johnstone 125 Welney Washes. Peter Scott 130 The Slimbridge observation hides. C. J. Beale and F. S. Wright 137 Current reports : Wildfowl survey in south-west Asia, 1967 144 Wildfowl ringing in Britain, 1966 and 1967 147 Reports from Abberton, Borough Fen and Dersingham Ringing Stations, 1967 149 Wildfowl censuses and counts in Britain, 1966-67 and 1967-68 156 Loch Leven, 1967 159 Slimbridge : wild geese, 1966-67 and 1967-68; Bewick’s Swans, 1967-68 161 Slimbridge and Peakirk collections : breeding results, 1967 164 Annual Report of the Wildfowl Trust 167 4 Wildfowl Editorial Since 1961 the Annual Report of the less there is a strong demand for it to be Wildfowl Trust has been divided into printed as a ‘ drop-out ’. two parts. One was the annual report In these days of the ‘information ex­ proper, an account of the Trust’s activi­ plosion’ when specialist journals prolif­ ties for its Members. The other was the erate (the prospectus for the ‘ Proceedings Yearbook, consisting of papers relating of the Society for the Study of Inborn to the conservation and study of wildfowl, Errors of Metabolism ’ is the latest to not necessarily written by members of the come our way), we would emphasise that Wildfowl Trust staff. The value of the we are not starting a new journal, nor will forum thus provided has been widely it be a particularly specialist one. Apart acclaimed. from their own fascination as a group of Two difficulties have arisen, however, birds, the wildfowl are ‘biological indi­ from the continuing use of the title W ild­ cators ’ for the condition of wetlands, of fowl Trust Annual Report. On the one all habitat the most threatened by Man’s hand some Members have felt that too attrition of his environment. A wide much money was being spent on an range of disciplines and interests thus ‘ annual report On the other hand, come to bear on wildfowl and their libraries and individual research workers, ecological associates, the wading birds. not conversant with its contents, neglected Our aim will be to publish articles our journal because they did not want, readily understandable by specialists in understandably, to clutter their shelves other fields and by the intelligent layman. with ‘ annual reports ’ from sundry organ­ And, since most of the species involved isations. Apart from the question of sales are migratory, the international aspects of (and the larger the number printed the the research and conservation methods lower the cost per copy), the library at need no stressing. It is reflected in the Slimbridge could benefit by an increase in wide geographical coverage of the articles. the number of exchanges which already Definitive articles and research reports brings in many journals to its shelves. form the bulk of WILDFOWL. They After considerable discussion by our are followed by a series of Current Council and Scientific Advisory Com­ Reports on regular research and conser­ mittee, it has been decided that both the vation activities concerned with wildfowl, difficulties could be resolved by a change both wild and in captivity, mostly under of name, to a title more truly indicative the auspices of the Wildfowl Trust. of its contents. Finally comes the Annual Report of that As will be appreciated, the choice of organisation to its Members. The photo­ name has not been easy. It was desirable graphic section has been dispersed that continuity of reference to previous through the volume instead of being issues of our journal should not be lost. gathered in one group, as in the past. This meant that there should not be a We would like to emphasise that there complete change of title, for instance to is nothing sacrosanct in any of these Anser. For a time Wildfowl Trust Annual arrangements and we welcome suggestions Review seemed a possibility, particularly from readers as to how WILDFOWL as we hope to increase the number of could be improved. We also welcome review articles. However, other types of articles and reports of the range and type article would still appear and there is indicated above, likewise photographs certainly a preference nowadays for short, and line drawings of high quality. In­ snappy, titles. The decision has therefore structions to contributors are printed on been made to take the first word of the the inside back cover. previous title and to call our journal It would be inappropriate to close this ‘ Wildfowl’. The numbering sequence of editorial without a tribute to the energy the volumes will be retained, so this suc­ of Hugh Boyd, who, building on the in­ cessor to the Wildfowl Trust Eighteenth spiration of Peter Scott, raised the W ild­ Annual Report, 1965-66 published in fowl Trust Annual Report to the status 1967, will be known as WILDFOWL 19, of an international journal. We wish him published in 1968. The annual report well in his new post in Canada, and seek section will continue to be bound in, un­ to carry on, and develop, his good work. The Moult Migration 5 The moult migration FINN SALOMONSEN Introduction (English : moult migration, French : The flight- and tail-feathers are shed migration de mue, German: M auserzug simultaneously in wildfowl, auks, divers, Danish: fœldningstrœk). The importance rails and a number of other groups, thus of this phenomenon was not realised un­ rendering the birds flightless and rather til 10-20 years later. In 1937-39 the Rus­ helpless for a period each year. The birds sians Vuczeticz and Tugarinov published withdraw at this critical time to special the results of wildfowl ringing in the areas where they are safe, usually to Soviet Union and demonstrated that en­ secluded places in dense marshes, lakes, ormous numbers of dabbling ducks origi­ coastal waters or the open sea. The main nating from northern Europe and Asia, requirements of such areas are sufficient gathered in the Volga delta in order to food, safety from predation, and (in water moult their flight-feathers there. Subse­ birds) an adequate depth of water. If quently, Stresemann (1940) described a these conditions are not met on the breed­ similar phenomenon from a lake on the ing ground or its immediate vicinity, the border between Tibet and Sikkim where, birds make a pre-moult shift to areas at an altitude of about 4,500 m., a num­ further away. This has in some cases ber of dabbling ducks and Tufted Duck resulted in a mass transfer of individuals shed their flight-feathers after a migra­ in a fixed direction towards localised tion of about 2,000 km. from their breed­ moulting places. This so-called ‘ Moult ing places in northern Siberia. Migration’ is particularly highly devel­ Not until 1942, however, was the moult oped in wildfowl. migration of a species in Europe des­ A comparative analysis of our recent, cribed, i.e. that of the Shelduck (Hooger- and incomplete, knowledge of moult heide and Kraak 1942). In North America migration has hitherto not been no real movements to moulting areas attempted. were described until well after 1950. History General Remarks The existence of moult migration was In the best developed form, moult unknown until 30-40 years ago, but in migration is from the breeding place to recent years many investigations have a special moulting area, common to a been carried out. The first to draw atten­ large number, in some cases hundreds of tion to this form of migratory movement thousands, of birds. When the flightless was the Swedish zoologist Sven Ekman, stage is over the ordinary autumn migra­ who in 1922 described it in the Eider*, tion to the winter quarters starts. This the Mute Swan and the Lesser White- form of moult migration cannot be re­ fronted Goose (Ekman 1922).