Site fidelity and survival of Purple Sandpipers Calidris maritima at Helgoland (SE North Sea)

Abstract

The minimum annual survival of Purple Sandpipers as derived from resighting rates in a colour‐ringed population at Helgoland (SE North Sea) was higher in adults (80%) than in first‐year birds (36%). In both first‐year and adult birds, the minimum survival during four winter months (60% and 84%, respectively) was slightly lower than during the eight months from spring to autumn arrival (63% and 85%, respectively). The high winter survival (100%) and low summer survival (64%) of second‐year birds is discussed in relation to different levels of experience in the wintering and first breeding, respectively. Although dispersal to other wintering sites cannot be totally excluded, the disappearance of individuals can generally be attributed to predation (by Sparrowhaioks Accipiter nisus, feral cats). Within Helgoland, a high fidelity to feeding sites and night roosts was recorded.