Abstract. Population viability analysis (PVA) has become a basic tool of current conservation practice. However, if not accounted for properly, the uncertainties inherent to PVA predictions can decrease the reliability of this type of analysis. In the present study, we performed a PVA of the whole western European population (France, Portugal, and Spain) of the endangered Bonelli's Eagle (Aquila fasciata), in which we thoroughly explored the consequences of uncertainty in population processes and parameters on PVA predictions. First, we estimated key vital rates (survival, fertility, recruitment, and dispersal rates) using monitoring, ringing, and bibliographic data from the period 1990-2009 from 12 populations found throughout the studied geographic range. Second, we evaluated the uncertainty about model structure (i.e., the assumed processes that govern individual fates and population dynamics) by comparing the observed growth rates of the studied populations with model predictions for the same period. Third, using the model structures suggested in the previous step, we assessed the viability of both the local populations and the overall population. Finally, we analyzed the effects of model and parameter uncertainty on PVA predictions. Our results strongly support the idea that all local populations in western Europe belong to a single, spatially structured population operating as a sourcesink system, whereby the populations in the south of the Iberian Peninsula act as sources and, thanks to dispersal, sustain all other local populations, which would otherwise decline. Predictions regarding population dynamics varied considerably, and models assuming more constrained dispersal predicted more pessimistic population trends than models assuming greater dispersal. Model predictions accounting for parameter uncertainty revealed a marked increase in the risk of population declines over the next 50 years. Sensitivity analyses indicated that adult and pre-adult survival are the chief vital rates regulating these populations, and thus, the conservation efforts aimed at improving these survival rates should be strengthened in order to guarantee the long-term viability of the European populations of this endangered species. Overall, the study provides a framework for the implementation of multi-site PVAs and highlights the importance of dispersal processes in shaping the population dynamics of long-lived birds distributed across heterogeneous landscapes.

Summary1. Over a large part of its very restricted and fragmented range, Iberian lynx Lynx pardinus occur in remote mountainous country at low density, where the only information about the species comprises records of incidental sightings obtained by inquiry. In this study we developed an approach for quantifying lynx±habitat relationships and distribution patterns from sighting data, using records from western Algarve (Portugal) in 1990±95. 2. Habitat was described in terms of land cover, topography, human disturbance and rabbit abundance, in 25-km 2 cells surrounding lynx sightings and at random locations within the study area. 3. Lynx sightings were consistently associated with predictable habitat features. Sighting probabilities estimated from a logistic regression model increased with the abundance of rabbits and the proportion of land covered by tall Mediterranean maquis, and declined with road density and the amount of developed land. This model identi®ed correctly 85´7% of lynx sightings; at the same time only 20´7% of the random locations were misclassi®ed. 4. Indices of human presence were never associated positively with lynx sightings, suggesting that observation patterns were not in¯uenced by the spatial distribution of potential observers. 5. Kriging was used to interpolate spatially between sighting probabilities derived from the logistic model in order to produce a map of sighting potential for the Iberian lynx in western Algarve. Jack-knife resampling assessed the accuracy of this map. Three well-de®ned areas of high sighting potential were identi®ed, probably representing the lynx core areas in this region. 6. Our analysis of lynx sighting records suggests that these data may provide a ®rst approximation to lynx habitat and distribution when further information is lacking. The application of this approach to other rare and reclusive species is discussed.

Aim To explore the influence of an emerging infectious disease (EID) affecting a prey species on the spatial patterns and temporal shifts in the diet of a predator over a large geographical scale. We reviewed studies on the diet of Bonelli's eagles (Hieraaetus fasciatus) in order to determine the repercussions of the reduction in the density of its main prey, the rabbit (Oryctolagus cuniculus), caused by outbreaks of rabbit haemorrhagic disease (RHD) since 1988.Location Western continental Europe. MethodsWe compiled published and unpublished information on the diet of breeding Bonelli's eagles from Portugal, Spain and France for a 39-year study period . Nonparametric tests were used in order to analyse temporal shifts in diet composition and trophic diversity (H¢) between the periods of 'high' (before outbreak of RHD) and 'low' rabbit density (after outbreak of RHD). A combination of hierarchical agglomerative clustering and non-metric multidimensional scaling (NMDS) analyses were used to test for the existence of geographical patterns in the diet of Bonelli's eagles in each period. ResultsThe diet of the Bonelli's eagle consisted of rabbit (28.5%), pigeons (24.0%), partridges (15.3%), 'other birds' (11.6%), 'other mammals' (7.1%), corvids (7.0%), and herptiles (6.4%). However, RHD had large consequences for its feeding ecology: the consumption of rabbits decreased by one-third after the outbreak of RHD. Conversely, trophic diversity (H¢) increased after outbreak of RHD. At the same time, the analyses showed clear geographical patterns in the diet of the Bonelli's eagle before, but not after, RHD outbreak.Main conclusions Geographical patterns in the diet of the Bonelli's eagle in western Europe seem to be driven mainly by spatio-temporal variation in the abundance of rabbits and, to a lesser extent, by the local (territorial) environmental features conditioning the presence and density of alternative prey species. We show that an EID can disrupt predator-prey relationships at large spatial and temporal scales through a severe decline in the population of the main prey species. Hence we argue that strict guidelines should be drawn up to prevent human-aided dissemination of 'pathogen pollution', which can threaten wildlife not only at the population and species level but also at the community and ecosystem scale.

Summary 1.Predator conservation management requires detailed understanding of the ecological circumstances associated with predation, especially that on economically valuable prey. We examined the mechanisms behind Bonelli's eagle Hieraaetus fasciatus predation on prey of domestic origin, using dietary data from 22 pairs breeding in south-west Portugal (1992Portugal ( -2001 together with information on landscape composition and prey availability. 2. Numerically, 42·7% (37·7% in biomass) of eagle prey comprised domestic species, about 70% of which were rural pigeons Columba livia and the remainder were racing pigeons Columba livia and domestic fowl Gallus gallus . Rabbits Oryctolagus cuniculus , red-legged partridges Alectoris rufa and jays Garrulus glandarius were the most frequent wild prey (43·1%; 50·8% in biomass). This dietary pattern was remarkably stable over a decade, but within each year the intake of pigeons almost halved over the course of the breeding season. 3. Landscape composition significantly affected the dietary proportion of wild and domestic prey items. This was particularly evident in territories dominated by eucalyptus Eucalyptus globulus plantations, where there was reduced consumption of rural pigeons and partridges, an increased intake of minor avian prey items and greater diversity in the diet overall. 4. Bonelli's eagles showed type II functional responses while preying on the most important wild (rabbit) and domestic (rural pigeon) prey, although the former was much stronger. Eagle predation on rabbits declined with increasing abundance of pigeons, and vice versa, but there was no switching in the traditional sense, as selection between these two species was inversely frequency dependent. 5. Synthesis and applications . Predation by Bonelli's eagle on domestic pigeons results from a combination of high vulnerability of the pigeons to eagles and a shortage of key wild prey such as rabbits and partridges, especially during the early breeding season. Given the relatively low economic value of rural pigeons and their importance in the diet of Bonelli's eagles, they could probably be used as a conservation tool to enhance food resources in breeding territories and to deflect predation from more valuable prey such as partridges and racing pigeons.

Although scrub cover is generally regarded as an important habitat component of the European wild rabbit Oryctolagus cuniculus, little is known about the species' responses to variation in scrub structure and composition. Such information is required for conservation management of rabbits in Mediterranean scrublands of the Iberian Peninsula (southwestern Europe), where the species is both a key resource for a range of endangered predators and a popular game species. To address this issue, we estimated the effects of variables characterising scrub vegetation on the occurrence and number of rabbit latrines in 60 250-m transects distributed in a 5,000-ha scrubland-dominated landscape in southwestern Portugal. The strongest effect was that of cover by the shrub Cistus ladanifer, which was positively related to both the occurrence and relative abundance of rabbits. Conversely, rabbits showed negative responses to cover by Chamaespartium tridentatum, ericoid and other broad-leaved shrubs. Rabbits favoured scrubs with a low density of woody vegetation at the ground level, but with a dense overhead cover. The herbaceous layer was also influential with positive effects of cover by grasses under the scrub and by forbs at the edge of the scrub. Taken together, our results suggest that conservation management of rabbit habitats in southwestern Portugal should strive to maintain scrub patches with a combination of favourable characteristics, including dense overhead cover but open access at the ground level, a developed herbaceous layer and woody species providing feeding opportunities during the summer period.