To predict future changes in wintering dabbling duck (Anas sp.) distributions in response to climate change, it is necessary to understand their response to temperature at a continental scale. Food accessibility, competition and thermoregulatory costs are likely to play a major role in determining the wintering distribution of short- to medium-distance migratory bird species and in determining how this distribution varies between years. As avian thermoregulatory costs scale allometrically with body size, it would be expected that the mean mid-winter temperature experienced by six species of dabbling ducks wintering in Western Europe would be negatively correlated with body mass. We found no clear evidence for such a relationship in a large-scale analysis, nor were there relationships between weighted mean latitude and longitude and mean January temperature experienced by each species. These results suggest that temperature is less important in shaping mid-winter duck distributions than factors such as feeding ecology.
Ibis, 2013, Vol 155, Issue 1, p. 80-88
Anas acuta; Anas clypeata; Anas crecca; Anas penelope; Anas platyrhynchos; Anas strepera; Bergmann's rule; climate change; lower critical temperature; thermoregulation