Winter weights and age structure of a population of pied wagtails at a Southern Scotland roost

Open Access
Publisher Website
Google Scholar
Abstract
A winter roost of up to 300 Pied Wagtails in Edinburgh, Lothian, was studied over four seasons. Mist‐netting the birds as they entered the roost revealed a ratio of first‐year to adult birds of approximately 3:1. Adult mean weights were usually higher than those of first‐year birds caught at the same time. Mean weights of first‐year birds increased from November through December, to peak in January. Sources of bias in the data are discussed, and attention drawn to their implications for studies based on mist‐netting birds at roosts. The results from the Edinburgh study are compared with those from central and south‐west England, and from Highland Region, Scotland — there appear to be differences in the age structures of the roosts, with relatively more adults being captured further north.