Changes in the wintering population and distribution of Slavonian Grebes in Shetland

摘要

In Shetland, wintering Slavonian Grebes Podiceps auritus occupy sheltered voes and feed in water depths of less than 20 m over muddy and sandy sediments. Systematic counts found that the wintering population in the islands doubled from just under 100individuals in 2000/01 to just over 200 in 2011/12; and there is good evidence to assume that it has quadrupled in the past 30 years. In parallel with this increase, Slavonian Grebes now winter in areas where there had previously been no records.This trend is likely to be a result of an increase in the Icelandic breeding population. Recent counts from Shetland, Orkney and the Outer Hebrides indicate that some 600 individuals now winter in these three archipelagos and account for a much greater proportion of the British wintering population (c. 55%) compared with 20 years ago (<20%).