Autumn Movements of Willow Warblers ringed in the British Isles

Open Access
Publisher Website
Google Scholar
Abstract
The autumn migration of Willow Warblers ringed in the British Isles was examined using recoveries of 356 birds ringed in Britain and nine on the Continent. Young British Willow Warblers undertook local random dispersal up to the end of July and began emigration around the end of July/early August when about 60 days old and probably just finishing post‐juvenile moult. Peak migration through Britain occurred over the period 11–20 August and the majority had left Britain by the end of August. Direction of migration through Britain was south to south‐south‐east. The movements of birds through Britain were probably of moderate distances, each possibly of between 50 and 300 km. Longer distance flights may have been made by later brood British birds. Relevant adult recoveries were few but showed no obvious differences to those of young birds in regard to timing and direction of migration through Britain, but young birds occurred in Iberia on average 12 days before adults. Trans‐Saharan flight probably started from Northern Iberia since few recoveries came from Southern Spain or Morocco. The few African recoveries indicated the countries around the Gulf of Guinea as the main wintering area of British Willow Warblers.