Crossing the desert barrier: Migration ecology of the Lesser Whitethroat ( Sylvia curruca) at Eilat, Israel

Abstract

The Lesser Whitethroat is a very common passerine species with two of the main populations breeding in Europe and in southwest Asia, both wintering in East Africa. These populations must therefore cross the Sahara-Arabian desert belt twice each year. Ring recoveries from northwestern Europe indicate the importance of the eastern Mediterranean flyway between breeding and wintering grounds for this species funneling through Israel. The aim of the study was to describe the staging patterns and phenology of migratory Lesser Whitethroat at the Eilat stopover site located on the threshold of the Sahara-Arabian desert. The number of individuals ringed in spring was on average as much as 25.2 times higher than in autumn passage. We did not find any significant differences in age ratios between passage seasons; however in both seasons adults were recorded earlier than juveniles. Furthermore, the body condition was better during autumn than spring. An analysis of Lesser Whitethroats recaptured during spring passage showed that Eilat is a suitable stopover site for both age classes, which displayed similar staging pattern. Recaptured birds were in better body condition than at first capture, and the improvement of body condition was positively connected with the length of stay at the stopover site.