Dispersed breeding areas and winter site fidelity in a northeast Atlantic Slavonian Grebe Podiceps auritus

Slavonian Grebes are patchily distributed in Europe, including in countries bordering the northeast Atlantic. The small breeding population in Scotland is of conservation concern, having declined to only 25 breeding pairs, and efforts to understand factors underlying this decline are hampered by a lack of knowledge of year-round movements, particularly outside the breeding season. Here, we present information on the movements of one female tracked over three years using an archival light logger, showing apparent breeding dispersal between sites separated by over 1200 km. After first breeding in Scotland, the grebe spent two summers in Iceland, before returning again to breed in Scotland. It also returned repeatedly to a wintering area off the southwest coast of Scotland. Broad conclusions cannot be drawn from the single bird tracked by this study, but the findings nevertheless suggest that movements can and do occur between North Atlantic breeding populations of Slavonian Grebes, indicating that dispersal may play a role in contributing to the regional population dynamics of this species.