Low fitness at low latitudes: Wintering in the tropics increases migratory delays and mortality rates in an Arctic breeding shorebird.

ABSTRACT: Evolutionary theories of seasonal migration generally assume that the costs of longer migrations are balanced by benefits at the non-breeding destinations. We tested, and rejected, the null hypothesis of equal survival and timing of spring migration for High Arctic breeding sanderling Calidris alba using six and eight winter destinations between 55°N and 25°S, respectively. Annual apparent survival was considerably lower for adult birds wintering in tropical West Africa (Mauritania: 0.74 and Ghana: 0.75) than in three European sites (0.84, 0.84 and 0.87) and in subtropical Namibia (0.85). Moreover, compared with adults, second calendar-year sanderlings in the tropics, but not in Europe, often refrained from migrating north during the first possible breeding season. During northward migrati

SUBMITTER: Reneerkens J 

PROVIDER: S-EPMC7078868 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature