Comparing the seasonal survival of resident and migratory oystercatchers: carry‐over effects of habitat quality and weather conditions (original) (raw)

Events happening in one season can aff ect life-history traits at (the) subsequent season(s) by carry-over eff ects. Wintering conditions are known to aff ect breeding success, but few studies have investigated carry-over eff ects on survival. h e Eurasian oystercatcher Haematopus ostralegus is a coastal wader with sedentary populations at temperate sites and migratory populations in northern breeding grounds of Europe. We pooled continental European ringing-recovery datasets from 1975 to 2000 to estimate winter and summer survival rates of migrant and resident populations and to investigate long-term eff ects of winter habitat changes. During mild climatic periods, adults of both migratory and resident populations exhibited survival rates 2% lower in summer than in winter. Severe winters reduced survival rates (down to 25% reduction) and were often followed by a decline in survival during the following summer, via short-term carry-over eff ects. Habitat changes in the Dutch wintering grounds caused a reduction in food stocks, leading to reduced survival rates, particularly in young birds. h erefore, wintering habitat changes resulted in long-term ( Ͼ 10 years) 8.7 and 9.4% decrease in adult annual survival of migrant and resident populations respectively. Studying the impact of carry-over eff ects is crucial for understanding the life history of migratory birds and the development of conservation measures.