Survival of breeders in a Danish Black-legged Kittiwake Rissa tridactyla colony - a capture-mark-recapture study

Abstract

The Black-legged Kittiwake Rissa tridactyla is one of the most numerous seabirds in the North Atlantic, but during the last couple of decades there have been reports of widespread large declines in breeding populations. In some areas, these declines are believed to be linked to lack of prey (Lesser Sandeel Ammodytes marinus) due to industrial fishing and increasing sea surface temperatures. In this paper, we explore the effect of sea surface temperature and age on survival of adult breeders in a small and relatively stable Danish colony of Black-legged Kittiwakes from 1992 to 2010. We found that survival did not vary significantly over the study period (mean 0.82), but was lower than reported from other studies. This could be due to a trade-off between reproduction and survival, leading to a lower survival, or it could be due to a high emigration leading to a too low estimate. Sea surface temperature had no effect on survival, contrary to other studies. Danish Black- legged Kittiwakes may rely on a food source which is not affected by the sea temperatures, either other species of fish or fishery discards. Finally, we found that survival decreased with age, in line with other studies.