Algeciras, Spain
Algeciras, Spain

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Marti B.,Fundacion Migres | Onrubia A.,Fundacion Migres | Ferrer M.,CSIC - Doñana 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.


de Lucas M.,CSIC - Doñana Biological Station | Ferrer M.,CSIC - Doñana 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.


Niamir A.,University of Twente | Niamir A.,Wageningen University | Skidmore A.K.,University of Twente | Skidmore A.K.,Wageningen University | And 3 more authors.
Diversity and Distributions | Year: 2011

Aim The spatial resolution of species atlases and therefore resulting model predictions are often too coarse for local applications. Collecting distribution data at a finer resolution for large numbers of species requires a comprehensive sampling effort, making it impractical and expensive. This study outlines the incorporation of existing knowledge into a conventional approach to predict the distribution of Bonelli's eagle (Aquila fasciata) at a resolution 100 times finer than available atlas data. Location Malaga province, Andalusia, southern Spain. Methods A Bayesian expert system was proposed to utilize the knowledge from distribution models to yield the probability of a species being recorded at a finer resolution (1×1km) than the original atlas data (10×10km). The recorded probability was then used as a weight vector to generate a sampling scheme from the species atlas to enhance the accuracy of the modelling procedure. The maximum entropy for species distribution modelling (MaxEnt) was used as the species distribution model. A comparison was made between the results of the MaxEnt using the enhanced and, the random sampling scheme, based on four groups of environmental variables: topographic, climatic, biological and anthropogenic. Results The models with the sampling scheme enhanced by an expert system had a higher discriminative capacity than the baseline models. The downscaled (i.e. finer scale) species distribution maps using a hybrid MaxEnt/expert system approach were more specific to the nest locations and were more contrasted than those of the baseline model. Main conclusions The proposed method is a feasible substitute for comprehensive field work. The approach developed in this study is applicable for predicting the distribution of Bonelli's eagle at a local scale from a national-level occurrence data set; however, the usefulness of this approach may be limited to well-known species. © 2011 Blackwell Publishing Ltd.


Lopez-Lopez P.,University of Valencia | Lopez-Lopez P.,Biodiversity Conservation Group | Ferrer M.,Biodiversity Conservation Group | Madero A.,Consejeria de Medio Ambiente | And 2 more authors.
PLoS ONE | Year: 2011

Background: Man-induced mortality of birds caused by electrocution with poorly-designed pylons and power lines has been reported to be an important mortality factor that could become a major cause of population decline of one of the world rarest raptors, the Spanish imperial eagle (Aquila adalberti). Consequently it has resulted in an increasing awareness of this problem amongst land managers and the public at large, as well as increased research into the distribution of electrocution events and likely mitigation measures. Methodology/Principal Findings: We provide information of how mitigation measures implemented on a regional level under the conservation program of the Spanish imperial eagle have resulted in a positive shift of demographic trends in Spain. A 35 years temporal data set (1974-2009) on mortality of Spanish imperial eagle was recorded, including population censuses, and data on electrocution and non-electrocution of birds. Additional information was obtained from 32 radio-tracked young eagles and specific field surveys. Data were divided into two periods, before and after the approval of a regional regulation of power line design in 1990 which established mandatory rules aimed at minimizing or eliminating the negative impacts of power lines facilities on avian populations. Our results show how population size and the average annual percentage of population change have increased between the two periods, whereas the number of electrocuted birds has been reduced in spite of the continuous growing of the wiring network. Conclusions: Our results demonstrate that solving bird electrocution is an affordable problem if political interest is shown and financial investment is made. The combination of an adequate spatial planning with a sustainable development of human infrastructures will contribute positively to the conservation of the Spanish imperial eagle and may underpin population growth and range expansion, with positive side effects on other endangered species. © 2011 López-López et al.


Ferrer M.,CSIC - Doñana Biological Station | De Lucas M.,CSIC - Doñana Biological Station | Janss G.F.E.,Asistencias Tecnicas Clave SL c Progreso 5 | Casado E.,Fundacion Migres | And 3 more authors.
Journal of Applied Ecology | Year: 2012

Wind farms generate little or no pollution. However, one of their main adverse impacts is bird mortality through collisions with turbine rotors. Environmental impact assessment (EIA) studies have been based on observations of birds before the construction of wind farms. We analysed data from 53 EIAs in relation to the actual recorded bird mortalities at 20 fully installed wind farms to determine whether this method is accurate in predicting the risk of new wind farm installations. Bird data from EIAs were compared with bird collisions per turbine and year at functional post-constructed wind farms to identify any relationship between pre- and post-construction studies. Significant differences in birds recorded flying among the 53 proposed wind farms were found by the EIAs. Similar results were obtained when only griffon vultures Gyps fulvus and other raptors were considered. There were significant differences in indexes, including the relative index of breeding birds close to proposed locations, among the 53 proposed wind farm sites. The collision rate of birds with turbines was one of the highest ever recorded for raptors, and the griffon vulture was the most frequently killed species. Bird mortality varied among the 20 constructed wind farms. No relationship between variables predicting risk from EIAs and actual recorded mortality was found. A weak relationship was found between griffon vulture and kestrel Falco sp. mortality and the numbers of these two species crossing the area. Synthesis and applications. There was no clear relationship between predicted risk and the actual recorded bird mortality at wind farms. Risk assessment studies incorrectly assumed a linear relationship between frequency of observed birds and fatalities. Nevertheless, it is known that bird mortality in wind farms is related to physical characteristics around individual wind turbines. However, EIAs are usually conducted at the scale of the entire wind farm. The correlation between predicted mortality and actual mortality must be improved in future risk assessment studies by changing the scale of these studies to focus on the locations of proposed individual wind turbine sites and working on a species specific level. © 2011 The Authors. Journal of Applied Ecology © 2011 British Ecological Society.


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.


Ferrer M.,CSIC - Doñana Biological Station | Bildstein K.,Acopian Center for Conservation Learning | Penteriani V.,CSIC - Doñana Biological Station | Casado E.,Fundacion Migres | de Lucas M.,CSIC - Doñana 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.


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.


Marcia Barbosa A.,University of Évora | Marcia Barbosa A.,Imperial College London | Real R.,University of Malaga | Munoz A.-R.,Fundacion MIGRES | And 2 more authors.
Diversity and Distributions | Year: 2013

Models based on species distributions are widely used and serve important purposes in ecology, biogeography and conservation. Their continuous predictions of environmental suitability are commonly converted into a binary classification of predicted (or potential) presences and absences, whose accuracy is then evaluated through a number of measures that have been the subject of recent reviews. We propose four additional measures that analyse observation-prediction mismatch from a different angle - namely, from the perspective of the predicted rather than the observed area - and add to the existing toolset of model evaluation methods. We explain how these measures can complete the view provided by the existing measures, allowing further insights into distribution model predictions. We also describe how they can be particularly useful when using models to forecast the spread of diseases or of invasive species and to predict modifications in species' distributions under climate and land-use change. © 2013 John Wiley & Sons Ltd.


Natural hybridisation in Old World buzzards (Buteo) is an uncommon phenomenon with important ecological implications. This genus constitutes an intricate radiation of genetically poorly differentiated raptors whose taxonomic classification is a frequent subject of debate. We report the first case of successful hybridisation between the African subspecies of the Long-legged Buzzard Buteo rufinus cirtensis and Common Buzzard Buteo buteo buteo in a new contact zone in the Strait of Gibraltar (southern Spain). The hybrid offspring showed mixed characters from parental species indicating that, among others, hybridisation could explain the increasing presence of phenotypically odd reddish buzzards in southern Spain and northern Morocco. Given their close phylogenetic relation and their recently reduced allopatry, an increase in the hybridisation rate, fertile descendants and genetic introgression seem to be viable. We identify the potential contact zones where genetic monitoring is needed to gain insight on the real extent of this hybridisation and its possible effects on the current climate change scenario. © 2013 Copyright NISC (Pty) Ltd.

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