Recent prospects on trans-Saharan migration of songbirds

Many palaearctic migrants in tropical Africa have to cross the inhospitable land of the Sahara desert. Moreau (1961, 1972) hypothesized that these migrants crossed the Sahara in a single non-stop flight. Recent field data, however, revealed that some migrants stop-over in suitable desert habitats. The majority of grounded migrants showed a high body-mass and fat-loading, indicating sufficient reserves for onward flights. Further evidence on resting periods, retrapping rates and experiments with caged migrants supports the hypothesis of an intermittent migratory strategy, with regular stopovers during the day and flight at night, for some desert-crossing passerines.