MIGRATION ROUTES OF STEPPE EAGLES BETWEEN ASIA AND AFRICA: A STUDY BY MEANS OF SATELLITE TELEMETRY

• Published in: The Condor (Los Angeles, Calif.) Calif.), 2003-05, Vol.105 (2), p.219-227
• Main Authors: Meyburg, Bernd-U, Paillat, Patrick, Meyburg, Christiane
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal behavior; Animal migration behavior; Animal, plant and microbial ecology; Animals; Applied ecology; Aquila nipalensis; Artificial satellites; Autoecology; Autumn; Aves; Biological and medical sciences; Bird migration; Bird watching; Birds of prey; Coasts; Conservation, protection and management of environment and wildlife; Eagles; Electronic monitoring; FEATURE ARTICLES; Fundamental and applied biological sciences. Psychology; migration; Ornithology; Overwintering; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Return migration; satellite telemetry; Satellites; Sea birds; Seasonal migration; Spring; Steppe Eagle; Steppes; Telemetry; Transmitters; Vertebrata; wintering sites
• ISSN: 0010-5422; 1938-5129; 2732-4621
• DOI: 10.1650/0010-5422(2003)105[0219:MROSEB]2.0.CO;2

We trapped 16 Steppe Eagles (Aquila nipalensis) on migration and on their wintering grounds and fitted them with satellite transmitters, 15 of them in Saudi Arabia and one in South Africa. Seven of the 14 Steppe Eagles trapped in Arabia in autumn did not migrate to Africa but spent the winter in the Arabian Peninsula. One adult migrated to southern Africa. The other six wintered in northeastern Africa, in some cases north of Bab-el-Mandeb, the straits at the southeastern end of the Red Sea, which they had crossed to reach the African continent. On their spring migration all eagles wintering in Africa migrated via the Suez, Egypt–Eilat, Israel, area at the northern tip of the Red Sea. This loop migration around the Red Sea is probably caused by east winds that blow from October until April, making the return migration difficult via Bab-el-Mandeb. This finding should help to explain the difference in eagle numbers between spring and autumn at such migration bottlenecks as Eilat, Suez, and Bab-el-Mandeb. Unlike eagles coming from Sudan and Ethiopia, eagles wintering in southern Africa must make a considerable detour of over 1200 km to complete this loop. The increase in Steppe Eagles overwintering in Arabia has probably contributed to the decline in the number of birds passing through Eilat in spring during recent years. Rutas Migratorias de Aquila nipalensis entre Asia y África: Un Estudio por Medio de Telemetría Satelital Resumen. Atrapamos 16 águilas (Aquila nipalensis), incluyendo aves migratorias e invernantes (15 en Arabia Saudita y una en Sud África) y les colocamos transmisores satelitales. Siete de las 14 águilas atrapadas en Arabia durante el otoño no migraron hacia África, sino que invernaron en la Península Arábica. Aparte de un adulto que migró hacia el sur de África, las restantes seis invernaron en África oriental, en algunos casos al norte de los estrechos al extremo sureste del Mar Rojo (Bab-el-Mandeb) los cuales cruzaron para alcanzar el continente africano. Durante la migración primaveral, todas las águilas que invernaron en África migraron vía Suez y vía el área de Eilat, alrededor del extremo norte del Mar Rojo. La migración alrededor de este cuerpo de agua siguiendo una ruta diferente a la invernal, es probablemente causada por el viento que provenie del este entre octubre y abril, dificultando la migración de retorno vía Bab-el-Mandeb en febrero y marzo. Este descubrimiento debe ayudar a explicar la diferencia en los números entre prima