STOPOVER OF MIGRANTS FLYING ACROSS THE MEDITERRANEAN-SEA AND THE SAHARA

During autumn migration, passerines cross the Mediterranean Sea and the Sahara on a broad front. Only the Atlas region from Morocco to Tunisia offers good stopover sites with respect to food and water. All other areas in the desert are not suitable for fat accumulation. The number and size of the eases are too small to be of general importance for feeding or drinking. Nevertheless, migrants have been found resting in all habitats of the desert. Their condition, namely, fat stores and hydration state, is probably sufficient for a successful continuation of the desert crossing. The ratio of intermittent migrants (those who interrupt migration for a rest) to nonstop migrants (those who cross the desert in one flight) is not known. Recent results, however, indicate that about one-quarter of all migrants use an intermittent migratory strategy.