The numbers and distribution of scaup Aythya marila in Britain and Ireland

Abstract

The numbers and distribution of scaup in Britain and Ireland have been monitored since 1947 through the Wildfowl Trust's National Wildfowl Counts scheme and, since the late 1960s, through the Irish Wildbird Conservancy's wetland surveys. The results since 1960 are presented in this paper. In Britain, the predominant feature has been a huge proliferation, of up to 25 000 birds, in the Firth of Forth off Edinburgh from the mid-1960s to mid-1970s. The disappearance of this assemblage occurred in isolation from the trend elsewhere in the country, which has been fairly stable, with small influxes in recent cold winters. In Ireland, there are signs of a decline during the 1970s followed by a slight recovery. The total number in Britain and Ireland in the early 1980s is estimated to have been only 6000–7500. The concentration of the species in relatively few resorts and the lack of current knowledge of trends and population levels in northwest Europe as a whole are sources of concern.