Ardeola 2017 64 (2) 347-361.

 

 

Diet and breeding performance of the Golden Eagle Aquila chrysaetos at the eastern and western extremities of the Pyrenees: an example of intra-population variability

 

 

  [Dieta y parámetros reproductores del Águila Real (Aquila chrysaetos) en los límites oriental y occidental de los Pirineos: un ejemplo de variabilidad intrapoblacional]

  

Michel Clouet, Jean-François Gerard, Michel Goulard, Jean-Louis Goar, Luc Gonzalez, Isabelle Rebours & Christian Fauré

 

 

Cet article concerne le régime alimentaire et les paramètres de la reproduction de l’Aigle royal aux deux extrémités du versant nord des Pyrénées étudiés au cours de 10 années consécutives.

 Dans la région méditerranéenne des Corbières, les proies de l’Aigle royal sont dominées par le Lapin (31,5 %). Au Pays basque, soumis au climat atlantique, le régime alimentaire est beaucoup plus varié avec des indices de diversité les plus élevés pour l’espèce (indice de Levin : 12.14 au Pays basque vs 6.81 dans les Corbières) et le plus fort taux de prédation intra-guilde observée chez un grand prédateur.

 La proportion de reproductions réussies était significativement plus élevée dans les Corbières (60%) qu’au Pays basque (38.5%). De même pour la productivité avec 0,70 jeune par couple et par an dans les Corbières et 0,45 au Pays basque. Ces différences sont à mettre en relation au moins en partie avec les conditions climatiques et en particulier avec l’excès d’enneigement des montagnes basques au mois d’avril, alors que les autres variables retenues (densité, facteurs anthropiques, régime alimentaire) sont apparues sans influence.

 Les résultats de cette étude sont un bon exemple de variation intra-populationnelle

 aux extrémités d’un gradient géographique incluant climat et disponibilité de ressources alimentaires. Ils montrent aussi que le maintien d’un grand prédateur dans les milieux fortement anthropisés dépend largement de la tolérance humaine et de la disponibilité des ressources.

 

 

 

 

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Bloomsbury USA, 2016

                                    

 Flight Identification of Raptors of Europe, North Africa and the Middle East

  Dick Forsman

 

 Raptors are notoriously hard to identify, even if seen well. Contrary to expectation, it is actually easier to identify raptors in flight, rather than perched, and it is fortunate that most raptors are usually seen in flight! This is the ultimate flight-identification guide to Western Palearctic raptors. It covers 60+ species, and goes to subspecific level wherever needed. The geographical area covered is Europe, North Africa, the Middle East including the Arabian Peninsula, and east to Central Asia.

This is a photographic guide with stunning images, most of which have been reserved for Flight Identification of Raptors of Europe, North Africa and the Middle East and have never been published before. The thorough text covers every plumage and age in breathtaking detail, and each species are illustrated with a range of photographs covering all the principal plumages.

Please note that this book does not replace, but complements Forsman's other book, The Raptors of Europe and the Middle East: A Handbook of Field Identification. The latter dealt with identification of birds both perched and in flight, whereas the new guide focuses on in-flight identification only.

 

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 Whittles Publishing 2017

 

A fieldworker's guide to the Golden Eagle

Dave Walker

 

The Golden Eagle is generally thought to be a well-known and well-documented species. However, much of the available literature is not necessarily in a form that can readily be used in the field.

 In fact, although much existing information about Golden Eagles has little supporting evidence it is still largely accepted without question. This book addresses this important issue and in doing so the author queries numerous long-held beliefs about Golden Eagles. He suggests that failure to recognise the limitations of the available evidence is not only detrimental to understanding eagle ecology but that it can undermine conservation efforts. The Fieldworker’s Guide questions the reliability of existing knowledge and promotes a better understanding of the species through improved fieldwork.

 With 37 years of active, year-round investigative fieldwork experience of the Golden Eagle, the author has vast knowledge enabling him to shed light on these matters. He has a history of undertaking novel research on post-fledging studies, territories and the impact of changes in land use. In this context he discusses how best to undertake fieldwork to produce objective results, avoiding the influence of expectations and recognising the many pitfalls into which an unwary observer might stumble.

 The book objectively reviews all aspects of Golden Eagle ecology, taking examples from many different locations and from site-specific studies in Scotland to compare and contrast the reliability and relevance of the evidence, highlighting the differences between casual and intensive fieldwork. It reviews all the elements of Golden Eagle ecology, from the species status, through the activities and roles of eagles of different gender, age and status, via territories, food and breeding, to habitat preferences, usage and even the influence of weather and observer activity on behaviour and observations. It also gives due consideration to the failed and non-breeding elements of the population, topics that are widely ignored despite such eagles forming the bulk of the population for most of the year.

 To provide a better understanding of what fieldworkers and birdwatchers are likely to encounter, the author reviews the month-by-month activity of all classes of Golden Eagle and the influences that affect how their ecology is understood.

 

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