Changes in non-breeding distribution and habitat of Pochard Aythya ferina in Britain

Abstract

Pochard Aythya ferina wintering in Britain originate in the Baltic countries and the USSR at least as far east as 76°E. Numbers of British wintering pochard doubled between 1948–1951 and 1960–1962; analysis of National Wildfowl Counts since 1960 shows that this dramatic increase continued into the early 1970s. The British population peaked, as it did in the rest of western Europe, during the mid-1970s, with a stabilisation or a slight decline in numbers since that time. The mid-winter population increased from 12–15 000 in the early 1960s to an estimated peak of 50 000. Within Britain, there have been considerable increases in numbers wintering on gravel pits, and sympathetic management of floodlands has also attracted greater numbers of pochard. The most important wintering flock at Duddingston Loch, Edinburgh, which exceeded 8000 in the 1970s, has disappeared due to closure of sewage outfalls in the nearby Firth of Forth. Such changes in habitat use have resulted in the geographical redistribution of pochard within Britain during the last two decades.