Effects of age, territoriality and breeding on survival of Bonelli’s Eagle Aquila fasciata

International audience; Survival typically contributes most to population trends in long-lived birds and itsaccurate estimation is therefore vital for population management and conservation. Weevaluated the effects of age, territoriality and reproduction on survival in Bonelli’s EagleAquila fasciata through multistate capture-mark-recapture analyses on a long-termdataset. Monitoring was carried out in southeast France (1990–2008) and involved thesurveying of territorial Eagles, the marking of fledged chicks, and the recording of resightingsand recoveries of marked non-territorial and territorial birds. Survival improvedwith age, but territoriality was not retained in the best model; yearly survival was estimatedat 0.479 for fledglings (to 1 year of age), 0.570 for 1- and 2-year-olds, and 0.870for 3-year-old and older individuals. The second best model supported a furtherincrease in survival from 3-year-olds (0.821) to older individuals (0.880). In the thirdbest supported model, territoriality enhanced survival, but only in 2-year-olds (0.632vs. 0.562 for non-territorial). We found no correlation between the previous breedingstage and future survival, consistent with the long lifespan of the study species. Nevertheless,4-year-old and older successful breeders were more likely to breed the followingyear than failed adult breeders (0.869 vs. 0.582), suggesting that the cost of reproductionis small in comparison with the variation in quality among individuals or theirterritories.