Bonelli's Eagle Aquila fasciata is one of the rarest birds of prey in Europe, where it has suffered a significant decline in recent decades. We present information on the homeranges and spatial parameters of 18 Bonelli's Eagles radiotracked in 2002-2006 and describe the home-range probability kernel, distances moved, breeding area eccentricity, territorial overlap, nearest neighbour distance and breeding site fidelity, and assess the influence of sex, breeding status, season and geographical area on these parameters. Median home-range according to the minimum convex polygon (MCP) and 95% kernel were 50.3 and 36.1 km 2 , respectively. The median breeding area eccentricity was 1477 m. There was considerable overlap in the home-range of both sexes within pairs (MCP: 71.4% and 95% kernel: 98.5%), indicating close pair bonding and similar foraging patterns. Overlap in home-ranges of up to 15% between neighbouring individuals also occurred and was positively related to breeding pair density. There was no difference in spatial parameters between sexes or with breeding status, but during the non-breeding season Eagles had larger home-ranges and stayed further from nests. The high consistency across birds suggests a pattern of spatial use that is characteristic of this species. The high level of use of breeding areas and their surroundings (50% kernel) throughout the year makes it important that these areas be protected from human disturbance. Additionally, it is necessary that heavily used areas away from nesting sites, which are used for foraging and roosting, are identified, protected and managed in a sustainable fashion.

Power line casualties are considered one of the main causes of mortality in the endangered Bonelli's Eagle Hieraaetus fasciatus, although little is known about factors involved in collisions with wires and their consequences at population level. We studied 18 radio-tracked individuals to determine the risk of collision with power lines at two spatial scales (flight height and span crossings). Through logistic regression modelling we found that the risk of collision was mainly determined by eagles' home range use, being reduced in kernel 80%, kernel 95% and MCP respectively to 0.421, 0.114 and 0.032 times in comparison to risk associated to the 50% kernel area. In addition, the risk of collision increased in open habitats (around 1.5 times higher than in forested habitats) far from urban areas (2.345 times higher than near urban areas) that were good for hunting, and in cliff areas used for breeding and roosting, where eagles fly at a lower height (the probability of eagles flying at a low height was 1.470 times higher than in forested habitats). A significant positive correlation was found between territorial turnover rates and the risk ascribed to transmission lines with earth wires in 15 breeding territories. Moreover, this correlation had a higher significance for the 50% kernel area when transmission without earth wires and double circuit distribution lines were added, although no correlations were encountered for distribution lines. These results suggested that power line collisions might be more important than previously reported as a cause of mortality for the species and thus conservation actions should be applied in order to minimise their effects on population dynamics. Predictive models may be a useful tool in careful planning of new power line routes and the wire-marking of the existing ones. Kernel areas should be used rather than fixed radii given that distances from nests may not adequately match the risk of collision.

Identifying the priority habitats of endangered species is crucial to implementing effective conservation actions. We characterize the key habitats used by Bonelli's Eagle Aquila fasciata, an umbrella and flagship species that is endangered in Mediterranean countries. We radiotracked 17 breeding individuals (10 males and seven females) in Catalonia (NE Iberian Peninsula) and used compositional analysis to determine the key habitats in home-ranges of both sexes. The main habitats identified within the home-range area were scrubland, coniferous forests, cropland, sclerophyllous forests, rock outcrops and urban areas, with little difference in habitat use between the sexes. Bonelli's Eagles preferred rocky habitats as breeding areas and scrubland as foraging areas, as these hold the highest abundance of their main prey, Rabbits Oryctolagus cuniculus and Red-legged Partridges Alectoris rufa. Habitat selection varied seasonally in foraging areas: scrubland was the most preferred habitat type during the breeding season, whereas rocky areas were preferred during the non-breeding season (although scrubland was also highly selected). Urban areas were avoided both as breeding and as foraging areas. Home-range size was inversely correlated with the proportion of scrubland, suggesting that this is a key habitat for Bonelli's Eagle. To conserve this species effectively, policies that ensure the preservation of the cliffs used as breeding sites, as well as suitable management of the scrubland used for foraging, should be implemented in the areas inhabited by this species. The promotion of traditional land uses and management techniques that will enhance open areas in Mediterranean landscapes should in the future play an essential role in the conservation of Bonelli's Eagle in Mediterranean habitats.

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