Ernesto Álvarez's scientific contributions

Publications (24)

Chapter
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As mentioned in previous chapters, electrocution can occur in two ways: by contact between two conductors or, more frequently, by contact between a conductor and an earthed metallic structure (the crossarm itself or a ground wire), and birds are among the groups most seriously affected (Figures 88 and 89). Given the distance between supports, the s...
Article
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It was assumed that the Spanish breeding population of the red kite (Milvus milvus) was resident, hence their movements were restricted to their breeding area for their entire lifecycle. However, recent observations indicated that the post-reproductive strategies of the red kite in Spain are more diverse. We tagged 47 breeding adult red kites in Sp...
Article
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The juvenile dispersal of raptors is a crucial stage that stretches from parental independence to the establishment of the first breeding area. Between 2012 and 2020, 44 juvenile red kites (Milvus milvus) from the Spanish breeding population were tagged using GPS telemetry to study their dispersal. Juveniles left the parental breeding area at the e...
Chapter
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La dispersión juvenil o dispersión natal es el conjunto de movimientos explora-torios que realizan las aves antes de llegar a la edad adulta. En esta etapa, los juveniles tienen un comportamiento distinto al de los adultos, por lo que se la considera una etapa diferenciada con características propias. Los movimientos dispersivos juveniles se caract...
Chapter
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Las aves rapaces suelen adoptar dos estrategias tras la época de cría: el sedentaris-mo y la migración. Las aves sedentarias, o residentes, son aquellas que permanecen en torno a un mismo territorio sin realizar desplazamientos importantes durante el año. Las aves migradoras, al contrario, se desplazan cientos o miles de kilómetros tras la reproduc...
Preprint
Islands are key areas for biodiversity; however, they are extremely sensitive to anthropic actions. This has led to local species extinctions, especially large predators such as raptors. Consequently, reintroduction and conservation projects aimed at reversing population decline of endangered species have recently gained popularity. Nevertheless, t...
Article
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Los centros de tratamiento o vertederos de resi-duos sólidos urbanos siempre han despertado in-quietud por los problemas ambientales que produ-cen. Tradicionalmente los efectos más directos que se han valorado han sido la contaminación de las aguas y del aire y el impacto paisajístico. En la actualidad, tras el aumento de la utilización de es-tos l...
Poster
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A total of 53 individuals of 14 different species have been tagged. 14 of these individuals died, 4 disappeared and 27 remained alive for more than 3 months. Although G.E. Duke et al. (1981) considered "6 weeks of survival to be a minimum standard of success" (p.4), we believe that at least 12 weeks of survival are needed to assume a total incorpor...
Poster
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During a decade (2011-2020), GREFA (Group for the Rehabilitation of Native Fauna) collected data derived from the GPS tracking of 48 red kites (Milvus milvus, Linnaeus, 1758) in the center of the Iberian Peninsula. Within that sample we found 20 individuals that were rehabilitated in the wildlife hospital of the same organization, and that were rel...
Article
Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) with a well-known toxicity for old world vultures that ingest the carrion of domestic animals treated with it. Diclofenac intoxication was directly related to the dramatic declines in the populations of three native South Asian Gyps vulture species two decades ago. In 2013, this NSAID was...
Article
Full-text available
1. Long-distance migrations are among the most physically demanding feats animals perform. Understanding the potential costs and benefits of such behaviour is a fundamental question in ecology and evolution. A hypothetical cost of migration should be outweighed by higher productivity and/or higher annual survival, but few studies on migratory speci...
Preprint
Full-text available
Islands are key areas for biodiversity; however, they are extremely sensitive to anthropic actions. This has led to local species extinctions, especially large predators such as raptors. Consequently, reintroduction and conservation projects aimed at reversing population decline of endangered species have recently gained popularity. Nevertheless, t...
Poster
Full-text available
AQUILA a-LIFE wants to increase the presence of Bonelli´s eagle (Aquila fasciata) in the Western Mediterranean and reverse the declining trend of its population. This project could be considered as the second part of LIFE BONELLI because the reintroduction and reinforcement of wildlife projects often requires several stages for development. The fir...
Article
Full-text available
Disentangling individual-and population-level variation in migratory movements is necessary for understanding migration at the species level. However, very few studies have analyzed these patterns across large portions of species' distributions. We compiled a large telemetry dataset on the globally endangered Egyptian Vulture Neophron percnopterus...
Chapter
Full-text available
Madrid's black vulture population in 2017 is divided into six nesting areas distributed in the north and west of the community: Alto Lozoya, Bajo Lozoya, Cuenca Alta del Manzanares, Sierra de La Cabrera, Alberche Basin and Valdemaqueda. In 2017, 187 black vulture platforms were located in the Community of Madrid, of which 148 were occupied by pairs...
Chapter
Full-text available
El número de parejas de águila perdicera ha experimentado una ligera mejoría en la Comunidad de Madrid desde el anterior censo (2006). Este hecho se ha producido gracias a las liberaciones de la especie que se han producido en el marco del proyecto Life Bonelli y a la mitigación de sus amenazas, principalmente las electrocuciones.
Chapter
Full-text available
Por primera vez en un proyecto de este tipo se han marcado con emisores todos los ejemplares que se han liberado (n=92). Paralelamente, se han equi-pado con el mismo tipo de localizadores todos los pollos "silvestres" descendientes de ejemplares liberados, junto a otros de parejas instaladas en zonas donde se está realizando el proyecto LIFE Bonell...
Article
Pheomelanin contributes to the pigmentation phenotype of animals by producing orange and light brown colours in the integument. However, pheomelanin synthesis in melanocytes requires consumption of glutathione (GSH), the most important intracellular antioxidant. Therefore, a genetic control favouring the production of large amounts of pheomelanin f...
Article
Full-text available
Las nuevas técnicas de rehabilitación en fauna salvaje mejoran la adaptación al medio de ejemplares heridos. La fisioterapia es una de las técnicas que mejores resultados proporcionan. El presente estudio muestra diferentes aspectos dispersivos (dispersión natal, dispersión reproductiva, movimientos diferenciales entre individuos reproductores/no r...
Article
Full-text available
El acuciante descenso de la población ibérica de Águila-azor Perdicera (Aquila fasciata) lleva a pensar que la cría en cautividad y los proyectos de reforzamiento y reintroducción pueden ser un arma útil como medida de conservación para la especie. Con objeto de valorarla en la población de la especie en las sierras del suroeste de la Comunidad de...
Poster
Full-text available
GREFA is an NGO founded in 1981 and located in Madrid, Spain. In the beginning was a wildlife hospital and in 1994 founded a raptor breeding center. In this moment Bonelli's eagle, golden eagle, lesser kestrel, Eurasian black vulture.. are being breed in the center. Bonelli's eagle is listed endangered in Madrid, and the law 2/1991 sets the engagem...

Citations

... The captive breeding program has not been used to provide butterflies for the purpose of reintroduction to restored or existing but unoccupied habitat. Table 2. Number of larvae produced in captive propagation program (Pratt 2004(Pratt , 2005(Pratt , 2007Pratt & Emmel 1998;Pratt et al. 2000;Pratt & Stouthamer 2002). The numbers of larvae at the end of the year are listed, whether they were larvae of the year or from previous years. ...
... Some of these compounds have already been detected in carcasses supplied at feeding stations in Spain, evidencing that veterinary drugs can reach avian scavengers through their trophic chain (Herrero-Villar et al., 2020). In fact, NSAID intoxications caused by diclofenac and/or flunixin have already been confirmed in Eurasian griffon (Gyps fulvus) and cinereous (Aegypius monachus) vultures in Spain (Zorrilla et al., 2015;Herrero-Villar et al., 2020, 2021a, 2021b. ...
... Before sharing data, researchers should ensure that any data curation entity has explicit and legally vetted policies regarding protection of sensitive data and authorship. If such protections are in place, the benefits of data sharing far outweigh the risks, and will ultimately benefit raptor conservation efforts (e.g., , Buechley et al. 2021, Gauld et al. 2022. ...
... Los datos del censo realizado en 2014 a escala nacional arrojan para Aragón una regresión del número de ejemplares, estimando una pérdida de casi la mitad en veinte años (Molina, 2015), siendo Zaragoza la localización con un descenso más acusado, situación que hace pensar en proyectos de reintroducción o de cría en cautividad como herramientas de gran interés para la conservación de la especie (Iglesias et al., 2012). Siendo por tanto de gran relevancia conocer si existen patrones de comportamiento espacial diferente entre individuos marcados en libertad o cautividad. ...
... The extent and the pattern of migration may vary strongly among different taxa and even within the same taxon (Dingle and Drake 2007). Migratory behaviour in birds, in particular, shows a remarkable variability at species (Schmaljohann 2018;Anderson et al. 2020), population (Monti et al. 2018a(Monti et al. , 2018bPhipps et al. 2019) and individual levels (Shamoun-Baranes et al. 2017a;Tedeschi et al. 2020). One of the most extreme forms of intra-population variation in migratory behaviour is partial migration, where only a fraction of individuals are migrants (Chapman et al. 2011(Chapman et al. , 2014. ...
... Are melanin-based traits under genetic control more likely to occur in organisms with constant or predictable access to necessary dietary components while plastic phenotypes are more likely to occur in organisms with high diet variation? Strict genetic determination of melanin phenotypes can be costly in stressful environments (Galván, Moraleda, et al., 2017), while plasticity in response to diet may allow individuals to decrease investment in pigmentation and increase investment to competing traits when necessary. ...