Abstract
Capsule: Arrival fuel load of migratory passerine birds after the Sahara crossing in spring varied between oases of different habitat quality.
Aims To test: (1) if spring migrants reaching northern Africa with low fuel stopover in oases of species-specific suitable habitat; (2) whether migrants have sufficient fuel loads to reach southern Europe; and (3) if there is local variation.
Methods: We collected data from passerines caught at three different oases in southeast Morocco during the spring of 2011.
Results: In species typical of mesophilic vegetation in Europe, birds carrying lower fuel loads occurred at a stopover site with lusher vegetation than two oases located further south. By contrast, in species adapted to xerophilic vegetation, birds carrying high fuel loads were found in drier habitat.
Conclusion: When arriving in northern Africa, migrants stopover in oases of different habitat quality in a species-specific fashion. Fuel load is, except for a few Mediterranean species, sufficiently high to reach the south of Europe without needing to refuel. Significant differences between oases suggests that fuel loads of birds from a single site are non-representative of the entire region.

Arizaga, J., Maggini, I., Hama, F., Crespo, A., Gargallo, G. 2013. Site- and species-specific fuel load of European-Afrotropical passerines on arrival at three oases of southeast Morocco during spring migration. Bird Study 60(1), 11-21. https://doi.org/10.1080/00063657.2012.735222/00063657.2012.735222.