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Algeciras, Spain

Ferrer M.,CSIC - Donana Biological Station | Bildstein K.,Acopian Center for Conservation Learning | Penteriani V.,CSIC - Donana Biological Station | Casado E.,Fundacion Migres | de Lucas M.,CSIC - Donana Biological Station
PLoS ONE | Year: 2011

Background: Island faunas have played central roles in the development of evolutionary biology and ecology. Birds are among the most studied organisms on islands, in part because of their dispersal powers linked to migration. Even so, we lack of information about differences in the movement ecology of island versus mainland populations of birds. Methodology/Principal Findings: Here we present a new general pattern indicating that large birds with deferred sexual maturity are sedentary on islands, and that they become so even when they are migratory on the mainland. Density-dependent variation in the age at first breeding affects the survivorship of insular populations and this, in turn, affects the movement ecology of large birds. Because density-dependent variation in the age of first breeding is critical to the long-term survival of small isolated populations of long-lived species, migratory forms can successfully colonize islands only if they become sedentary once there. Analyses of the movement ecology of continental and insular populations of 314 species of raptors, 113 species of Ciconiiformes and 136 species of passerines, along with individual-based population simulations confirm this prediction. Conclusions: This finding has several consequences for speciation, colonization and survival of small isolated population of species with deferred sexual maturity. © 2011 Ferrer et al. Source

de Lucas M.,CSIC - Donana Biological Station | Ferrer M.,CSIC - Donana Biological Station | Bechard M.J.,Boise State University | Munoz A.R.,Fundacion Migres
Biological Conservation | Year: 2012

Wind is increasingly being used as a renewable energy source around the world. Avian mortality is one of the negative impacts of wind energy and a new technique that reduces avian collision rates is necessary. Using the most frequently-killed species, the griffon vulture (Gyps fulvus), we studied its mortality at 13 wind farms in Tarifa, Cadiz, Spain, before (2006-2007) and after (2008-2009) when selective turbine stopping programs were implemented as a mitigation measure. Ten wind farms (total of 244 turbines) were selectively stopped and three wind farms (total of 52 turbines) were not. We found 221 dead griffon vultures during the entire study and the mortality rate was statistically different per turbine and year among wind farms. During 2006-2007, 135 griffon vultures were found dead and the spatial distribution of mortality was not uniformly distributed among turbines, with very few turbines showing the highest mortality rates. The 10 most dangerous turbines were distributed among six different wind farms. Most of the mortalities were concentrated in October and November matching the migratory period. During 2008-2009, we used a selective stopping program to stop turbines when vultures were observed near them and the griffon vulture mortality rate was reduced by 50% with a consequent reduction in total energy production of by the wind farms by only 0.07% per year. Our results indicate that the use of selective stopping techniques at turbines with the highest mortality rates can help to mitigate the impacts of wind farms on birds with a minimal affect on energy production. © 2011 Elsevier Ltd. Source

Telleria J.L.,Complutense University of Madrid | Onrubia A.,Fundacion Migres
Ardeola | Year: 2012

This paper explores the changes in the number of diurnal migratory birds crossing the Strait of Gibraltar between 1977 and 2008, to test whether the numbers of birds wintering in the Maghreb have decreased over the last 30 years. Results show that the most abundant species in 1977 were the most abundant ones in 2008. However, they also showed a decrease in the relative contribution of partial migrant species. A similar analysis of data from the Falsterbo Observatory (Sweden) did not reveal any decreasing contribution of partial migrants to the flux of migrant birds moving from northern Scandinavia. Source

Perez-Rodriguez A.,Complutense University of Madrid | de la Puente J.,Autonomous University of Madrid | Onrubia A.,Fundacion Migres | Perez-Tris J.,Complutense University of Madrid
International Journal for Parasitology | Year: 2013

Despite the ecological significance and appeal of birds of prey, many aspects of their biology remain poorly known, including the diversity of parasites infecting them in the wild. We studied the diversity and prevalence of haemosporidian parasites infecting the two species of kites of the genus Milvus, aiming to describe the phylogenetic relationships among them and with other haemosporidians, as well as their distribution in the two host species. Black kites, Milvus migrans, harboured a more diverse community of parasites, including three haplotypes of each of the three genera Plasmodium, Haemoproteus and Leucocytozoon, which also occurred at a higher prevalence than in red kites. In red kites, Milvus milvus only three haplotypes of Leucocytozoon were found. Kite parasites were not closely related to one another nor were they kite-specific: their diversity spanned various branches of the haemosporidian phylogenetic tree, and their closest relatives were found in other species (including various avian orders), although some Leucocytozoon and Haemoproteus haplotypes clustered within apparently raptor-specific parasite clades. Remarkably, Plasmodium spp. and Haemoproteus spp. infected adult black kites only, an observation which supports the hypothesis that they are transmitted at the African wintering grounds, while Leucocytozoon spp. is putatively transmitted only in Europe. Intercontinental migration of the black kite might explain the divergence of parasite diversity between these two sister species. © 2013 Australian Society for Parasitology Inc. Source

Marti B.,Fundacion Migres | Onrubia A.,Fundacion Migres | Ferrer M.,CSIC - Donana Biological Station
Climate Research | Year: 2016

Our goal in this study was to identify age- and population-specific responses to climate change in the autumn migration phenology of a long-lived bird species, the white stork Ciconia ciconia, at the macroscale of its entire migration route in western Europe. We used a 40 yr data series of ring recoveries of adult (>1 yr) and juvenile (<1 yr) white storks to determine the date of autumn passage through the Strait of Gibraltar. We then modelled geographical variability in the timing of autumn migration between age classes across Europe from environmental conditions at the breeding grounds using age-specific generalized additive model (GAM) analysis. Best-fit models accounted for up to 31% of the variability in the data and indicated a progressively earlier passage date over the course of the 40 yr dataset. However, responses varied among populations and age classes. A trend towards earlier migration in juvenile storks was observed, whereas in adults the trend was highly variable between years. In addition, advances in autumn passage dates of juvenile birds were larger in southwestern Europe. Differences between white stork age classes in response to environmental conditions on the breeding grounds are likely caused by different mechanisms for migration adjustment governing adult and young bird behaviour. Overall, plasticity in adapting to new environmental conditions has allowed western European white storks to rapidly respond to, and even benefit from, recent climatic and environmental changes. © 2016 Inter-Research. Source

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