La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Interannual variations of reproductive parameters in a booted eagle (Hieraaetus pennatus) population: the influence of density and laying date
Auteurs :	Jose E. Martinez, Auteur ; Iluminada Pagan, Auteur ; Jose F. Calvo, Auteur
Type de document :	Article
Dans :	Journal of Ornithology (147(4) OCT 2006)
Article en page(s) :	612-617
Langues:	Anglais
Résumé :	A population of booted eagles (Hieraaetus pennatus) consisting of 21-29 pairs was studied for 7 years (1998-2004) in a forested mountainous region of southeastern Spain. The average egg-laying time was 25 April (earliest 31 March, latest 26 May). Sixty-eight percent of territorial pairs produced eggs, and 81% of reproductive pairs successfully raised at least one offspring. Mean clutch size was 1.91 eggs, and 84% hatched. The survival rate of chicks was high, with only 17% dying. The major known cause of nestling mortality was predation, mainly by the Eurasian eagle owl (Bubo bubo). The mean number of flying offspring was 0.91 per territorial pair, 1.29 per reproductive pair and 1.65 per successful pair. All population breeding parameters analysed were density independent, but most showed a significantly negative relationship with mean laying date.

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