How far do birds fly during one migratory flight stage?

Abstract

Birds on migration normally switch between flight stages and periods of stopover where fuel stores are replenished. How migratory birds divide their time between flight and stopover is still not well known. Short‐term recoveries of passerine birds ringed in Sweden were analysed to investigate how far long‐distance migrating passerines fly during a flight stage and whether they migrate one or more flight stages in a row. Included in the study were birds recovered at least 50 km from the ringing site and within seven days from ringing. The median distance covered by the recovered birds was 245 km. About 40% of the recoveries within 24 hours from ringing were found at least 200 km from the ringing site. The distances covered varied and many birds moved only short distances, perhaps as a result of searching for good stopover sites, while others moved much further away. Two recoveries of Sedge Warblers three days after ringing indicated that these birds had flown three nights in a row before being controlled. The results suggest that long‐distance passerine migrants regularly perform several flight stages in a row, with short rests in between, before refuelling, even if there are no major barriers ahead.