Netherlands Polar Data Center

Summary

The decline of long-distance migratory birds is a great challenge for European nature conservation. The Netherlands harbours many migratory birds in winter and during stopover. The Netherlands has taken up its international responsibility by listing Natura 2000 target species, including the Bewick's swan. This Arctic-nesting species has an unfavourable conservation status, with numbers wintering in the Netherlands declining dramatically since the mid-1990s. This proposed research is aimed at unravelling the cause of this decline. In contrast to resident species, the limitation of population size of migratory species can occur on breeding or wintering grounds, or even at stopover sites in between. Long-term population count data, mark-recapture data and productivity data are combined into a single unified analysis: an integrated population model. This will enable estimation of the contribution of survival, reproductive success and emigration to the observed trend in the Netherlands. The emigration estimated in this way consists of a change in wintering site, either by short-stopping or by changing flyway. Concurrent with the recent decline in Bewick's swans, mute swan and whooper swan populations have increased. Whooper swans are also migratory, but being larger are expected to winter further north and east, and to migrate slower. Using GPS-GSM-UHF collars, both Bewick's swans and whooper swans will be tracked from their joint moulting grounds in the Arctic to determine the potential locations of exploitative competition. The outcome of this study is expected to be of high relevance for the development of management actions for this Arctic-nesting, Natura 2000 target species.

People involved

Datasets

Publications

Kevin A. Wood, Rascha J. M. Nuijten, et al., 2018. Apparent survival of an Arctic-breeding migratory bird over 44 years of fluctuating population size. Ibis 160 (2), 413-430