Area de Estudio y Seguimiento de Aves

Madrid, Spain

Area de Estudio y Seguimiento de Aves

Madrid, Spain
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Finch T.,University of East Anglia | Saunders P.,University of East Anglia | Aviles J.M.,CSIC - Estación Experimental De Zonas Áridas | Bermejo A.,Area de Estudio y Seguimiento de Aves | And 16 more authors.
Diversity and Distributions | Year: 2015

Aim: The extent to which individuals from different breeding populations mix throughout the non-breeding season (i.e. 'migratory connectivity') has important consequences for population dynamics and conservation. Given recent declines of long-distance migrant birds, multipopulation tracking studies are crucial in order to assess the strength of migratory connectivity and to identify key sites en route. Here, we present the first large-scale analysis of migration patterns and migratory connectivity in the globally near-threatened European roller Coracias garrulus. Location: Breeding area: Europe; passage area: Mediterranean, sub-Saharan Africa, Arabian Peninsula; wintering area: southern Africa. Methods: We synthesize new geolocator data with existing geolocator, satellite tag and ring recovery data from eight countries across Europe. We describe routes and stopover sites, analyse the spatial pattern of winter sites with respect to breeding origin and quantify the strength of connectivity between breeding and winter sites. Results: We demonstrate the importance of the northern savanna zone as a stopover region and reveal the easterly spring loop (via Arabia) and leapfrog migration of rollers from eastern populations. Whilst there was some overlap between individuals from different populations over winter, their distribution was non-random, with positive correlations between breeding and autumn/winter longitude as well as between pairwise distance matrices of breeding and winter sites. Connectivity was stronger for eastern populations than western ones. Main conclusions: The moderate levels of connectivity detected here may increase the resilience of breeding populations to localized habitat loss on the winter quarters. We also highlight the passage regions crucial for the successful conservation of roller populations, including the Sahel/Sudan savanna for all populations, and the Horn of Africa/Arabian Peninsula for north-eastern rollers. © 2015 John Wiley & Sons Ltd.

Seoane J.,Autonomous University of Madrid | Carrascal L.M.,CSIC - National Museum of Natural Sciences | Palomino D.,Area de Estudio y Seguimiento de Aves | Alonso C.L.,University of Castilla - La Mancha
Bird Conservation International | Year: 2010

We estimated the breeding population size and assess the habitat relationships of Black-bellied Sandgrouse in the Eastern Canary Islands (Fuerteventura, Lanzarote and La Graciosa, Spain) by means of a survey based on 1,787 0.5-km line transects and distance sampling done in 2005 and 2006. The population comprised 2,906 individuals (90% CI: 2,363-3,562), which is much higher than the numbers estimated in previous reports based on partial surveys, and constitutes 20% of the total Spanish population. Sandgrouse in the Canaries are currently restricted to Fuerteventura, where 70% of the population gathers in four areas that encompass just 16.7 % of the island and are largely within Special Protection Areas classified under the EU Birds Directive (except the area of Tefia-Ampuyenta, first in absolute number of individuals). The environmental characteristics that maximize the probability of occurrence of the sandgrouse in Fuerteventura (probability = 0.196) are: treeless non-cultivated areas of sandy soils without bare bedrock, with a rock cover less than 44%, located in non-coastal areas with an average terrain slope less than 27.5%, at more than 400 m from the nearest urban area, with less than 795 m of dirt roads per 20 ha, with at least 0.9% of shrub cover and a NDVI index higher than 53. Sandgrouse were closer to human settlements in midsummer than in March, perhaps being attracted to artificial pools surrounding villages. Similar habitat characteristics exist in nearby Lanzarote, where the species could hypothetically reach densities as high as 4-5 birds km-2. Possible reasons for the absence of sandgrouse in this island are discussed. Copyright © BirdLife International 2009.

Carrascal L.M.,CSIC - National Museum of Natural Sciences | Cayuela L.,Rey Juan Carlos University | Palomino D.,Area de Estudio y Seguimiento de Aves | Seoane J.,Autonomous University of Madrid
Biological Conservation | Year: 2012

Identification of species-specific traits that make a species a better surrogate of biodiversity is a need in order to implement successful conservation programmes in the face of limited data and resources. This study analyzes the relationship between the abundance of different surrogate species and species richness for terrestrial native avifauna of autochthonous steppe and semiarid environments in Fuerteventura Island (Spain) at different spatial grains, and explores which species-specific ecological traits (body mass, ecological density, habitat breadth, coverage of urban and agricultural environments) and conservation features (endemicity, conservation status) make a species more efficient as a surrogate. Results indicate that abundance of those surrogate species which are typically targeted by local conservation managers (according to their rarity and increase public awareness) proves to be a poor predictor of three different measures of species richness of the native terrestrial avifauna of Fuerteventura at all spatial resolutions. Nonetheless, some species were found to perform better than others according to partial least squares regression analyses applied to relate species-specific ecological traits and conservation features with correlation coefficients between abundance of each bird species and total bird richness. The best surrogates for global bird species richness are those smaller birds of medium-high abundances, broad habitat preferences, less threatened status, and with a high degree of endemicity. No scale-dependency was observed in the surrogacy power of species. Conservation planners in island scenarios should use a selection of bird species with these characteristics to identify conservation target areas in order to maximize the efficiency of surrogacy approaches. © 2012 Elsevier Ltd.

Seoane J.,Autonomous University of Madrid | Carrascal L.M.,CSIC - National Museum of Natural Sciences | Palomino D.,Area de Estudio y Seguimiento de Aves
Journal for Nature Conservation | Year: 2011

Proneness to extinction varies naturally and continuously according to the ecological phenomena that compound rarity even before anthropogenic effects may play a role. This is particularly obvious in islands, where populations are often (and naturally) small and fragmented and, consequently, conservation priority lists may have a large number of species clustered unhelpfully in the higher threat categories. In this study we propose a simple model of threat based on natural descriptors of rarity and taxonomic distinctiveness (area of occupancy, population abundance and trend, and endemicity), assess its correlation with ecological features of the species (habitat preferences and body size) and check whether the Spanish Red data Book and a normative conservation priority list (the Canary Islands Catalogue of Threatened Species and its administrative revision) includes these ecological bases for birds. We found that a large variation in threat (48.2%) was explained by phylogeny, habitat breadth and preference for urban areas (with a negative effect), and preference for agricultural environments (a positive effect). The Spanish Red data Book and the administrative lists tested are poorly related to descriptors ordering the extinction risk and loss of taxonomic singularity, so some changes would make their categories more coherent. We contend that the ecological bases of rarity should be taken into account to understand why some populations/species are at higher extinction risk whereas others remain relatively safe, as this would provide firmer grounds on which to base conservation priorities. © 2010 Elsevier GmbH.

Seoane J.,Autonomous University of Madrid | Kouri A.,Autonomous University of Madrid | Illera J.C.,CSIC - Institute of Natural Products and Agrobiology | Illera J.C.,University of Oviedo | And 3 more authors.
Ardeola | Year: 2010

New data on the population, distribution and habitat preferences of the Canary Islands stonechat Saxicola dacotiae. This paper updates estimates of population size, distribution and habitat preferences of the endemic Canary Islands stonechat Saxicola dacotiae on the basis of data gathered across their whole distribution range, the island of Fuerteventura. We surveyed 1,462 0.5-km line transects during the reproductive seasons in 2005 and 2006, distributed across the whole island. Results were used to estimate population size using two methods: stratified estimates of mean densities and sum of estimated abundances across strata, and sum of estimations of abundance in 1 km x 1 km UTM squares based on statistical models built by boosted regression trees (BRT). In both methods we accounted for the effects of bird detectability in transects. Overall, 490 mature individuals were recorded. The Canary Islands stonechat preferred high, steep terrain (particularly above 20% slope and 200 m a.s.l.) and selected negatively the lower and flatter areas comprising most of the island. These habitats were occupied, however, albeit at low density. The highest average densities sampled per habitat (up to 43 birds/km2) were registered on steep areas (> 11%) with scrub, although the statistical models predicted densities of 66 birds/km2 in the optimum sites (slopes higher than 22.5% with rocky ground). The population size of Canary Islands stonechat estimated with the stratified design was 20,504 individuals (CI 95%: 16,217-25,973), and the modelbased estimate (which we consider more reliable) was 14,436 (CI 95%: 13,376-15,492). These estimates are much higher than previous ones. We argue it is difficult to compare with Bibby and Hill's (1987) results due to the different methodologies involved and areas covered by the monitoring programs, although we can not exclude an increase in population size during the last three decades. Discrepancies with GarcÍa del Rey's (2009) estimate appears to be due to an underestimate of the population size because of the lack of sampling in extensive areas and habitats of low bird density on the island.

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