Passa al contingut principal

From the Mediterranean Sea to Madagascar: Are there ecological barriers for the long-distance migrant Eleonora’s falcon?


Abstract We examined the connection between landscape characteristics and behaviour of a longdistance
migratory raptor. Our main goal was to test whether long-distance migratory birds adjust their migration programme according to the different characteristics of the habitats crossed during the journey with special emphasis in the so-called ‘‘ecological barriers’’, inhospitable environments such as deserts, ice fields, seas and mountain ranges, where the opportunities to fulfil energy requirements are low or absent and  environmental factors could be extremely severe. To this end, 11 Eleonora’s falcons were tracked by satellite telemetry in their ca. 9000 km autumn migration route from colonies located in Western Mediterranean to their wintering grounds in Madagascar during 2007 and 2008. Our results show that Eleonora’s falcons migrated during day and night-time, adjusting migration speed and daily distance in relation to the crossed region. Unlike other migrant species, Eleonora’s falcons did not avoid ecological barriers by making unnecessary detours around them or converging on narrow corridors. Nocturnal migration and higher daily distances were observed when flying across the Sahara Desert and the Mozambique Channel. The circadian pattern of activity budget shows that Eleonora’s falcon relies on an internal navigation mechanism that works during both day and night. Finally, our results suggest that the Sahara is an ecological barrier not only for passerines but also for raptors migrating within the Palaearctic-African flyway.
Keywords: Falco eleonorae ,Long-distance migration, Navigation ,Orientation Route convergence,  
Satellite tracking


Pascual López-López, et al. (2010) Landscape Ecol.  25

Etiquetes de comentaris:

Comentaris

Publica un comentari a l'entrada

Entrades populars d'aquest blog

Origin and abundance of beach debris in the Balearic Islands

RESUMEN: ORIGEN Y ABUNDANCIA DE RESIDUOS EN PLAYAS DE LAS ISLAS BALEARES. En un estudio realizado durante el año 2005 se analizó la abundancia, naturaleza y posibles orígenes de los residuos presentes en 32 playas de las Islas Baleares (mar Mediterráneo). La abundancia media de objetos en verano fue de aproximadamente 36 objetos por metro lineal, con un peso correspondiente de 32±25 g por metro lineal, lo cual es comparable a otros estudios en el Mediterráneo. El estudio mediante análisis multivariantes (Análisis de Componentes Principales y Análisis de Redundancia) confirma importantes similitudes entre islas, además de una evolución estacional estadísticamente significante en la composición y abundancia de los residuos. La contaminación durante el verano, expresada en términos de abundancia de objetos en la playa, duplica el valor registrado en invierno. Además, los objetos hallados durante esta época son de naturaleza heterogénea lo que se asocia c...
1 comentari
Més informació

Lizards as pollinators and seed dispersers: an island phenomenon

Although it is well established that many insects, birds and mammals serve as important pollinators and seed dispersers of flowering plants, the role of lizards in these processes has traditionally been considered as rare and less important. However, recent work shows both that their role as mutualistic agents has been underestimated and also reveals a striking pattern – that pollination and seed dispersal by lizards is most common on islands. We argue that this island phenomenon occurs because island lizards reach very high densities (density compensation) and experience a lower predation risk than do those on the mainland and, consequently, can expand their diet to include nectar, pollen and fruit. Although further empirical evidence is needed to confirm this explanation, such relationships could be ideal systems with which to study fundamental ecological problems, such as niche shifts, ecological release and competition. Jens M. Olesen a...
Publica un comentari a l'entrada
Més informació

Autumn Migration of Eleonora’s Falcon Falco eleonorae Tracked by Satellite Telemetry

Falco eleonorae tracked by satellite telemetry. Zoological Studies 48(4): 485-491. The migration route of Eleonora,s Falcon Falco eleonorae has largely been a mystery. To date, the most widely accepted hypothesis on Eleonora,s Falcon’s migration suggested a coastal route through the Mediterranean Sea eastwards, crossing the Suez Canal, and proceeding southwards through the Red Sea following the East coast of Africa to the wintering grounds in Madagascar and the Mascarene Is. This study provides the first description of autumn migration routes of 2 Eleonora,s Falcons (a juvenile male and an adult male) tracked by satellite telemetry from their breeding colonies in the Western Mediterranean to their wintering grounds in southeastern Africa. Contrary to previous suggestions, Eleonora,s Falcons migrated inland across the African continent and did not follow the presumed migration route across the Mediterranean Sea. We discuss the possible origin of this migratory b...
Publica un comentari a l'entrada
Més informació