Crossing the Sahara desert: migratory strategies of the Grasshopper Warbler
Although a quarter of Europe’s breeding bird population crosses the Sahara on spring and autumn migration, when, where and how species prepare for and recover from this difficult and dangerous part of their journey remains poorly understood. Recent work by the Wetland Trust and the BTO has used ringing datasets from Portugal and Senegal to explore these questions in the Grasshopper Warbler.
The data suggest that while many individuals use sites in Portugal in autumn and in Senegal in spring, they also stop and refuel at unknown sites in North Africa. Fuelling in Senegal for the north-bound migration was slow relative to rates recorded in Portugal, and likely to be constrained by food availability during the Sahelian dry season. A knowledge of the stopover sites used by migratory species is vital for their conservation, at a time when many trans-Saharan migrants are in decline.
Full citation: Bayly N.J., Rumsey S.J.R. & Clark J.A. 2011. Crossing the Sahara desert: migratory strategies of the Grasshopper Warbler Locustella naevia. Journal of Ornithology 152, 933-946. doi: 10.1007/s10336-011-0676-3