The population biology of Common Sandpipers in Britain

The population biology of Common Sandpipers Actitis hypoleucos has been studied, especially by colour-ringing breeding adults, at two sites, in the Peak District and in the Scottish Borders. Adults are usually site-faithful, males more so than females, contributing to a good apparent survival rate (72% and 67%, respectively). Some, at least, return to breed at one year old, but usually not to the site where they hatched. The population in Britain seems to be in slow decline, most obviously indicated by a contraction along the edges of its range, which results especially from poor recruitment of young birds.This does not seem to be due to poorer breeding success, but it is uncertain whether it is caused by a subtle effect of climate change, change in quality of stopover sites on migration, or changes in wintering habitat. Since we don't know precisely where British birds spend the winter, the last possibility is especially hard to evaluate. © British Birds.