Data Zone
Justification of Red List category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
The European population is estimated at 1,100-1,200 pairs, which equates to 2,100-2,400 mature individuals (BirdLife International 2015). Europe forms approximately 10% of the global range, so a very preliminary estimate of the global population size is 21,000-24,000 mature individuals, although further validation of this estimate is needed (BirdLife International 2015).
Trend justification
The population is declining drastically throughout its range owing to over-use of pesticides, habitat degradation, loss of prey species, collision with power lines and persecution by hunters and pigeon fanciers (Ferguson-Lees and Christie 2001, Barov and Derhé 2011). In Europe the population size is currently stable, but it is estimated to have decreased in the past at a rate approaching 30% in 54 years (three generations) (BirdLife International 2015).
Behaviour The species has a fragmented distribution across the southern Palearctic and Indomalayan regions, and is marginally Afrotropical (45°N to 10°S). It is locally uncommon to rare and in decline across its range. The species is resident throughout its range, although juveniles will disperse up to 200km with individuals occasionally wandering further afield and passing through key migration routes (Ferguson-Lees and Christie 2001, Shirihai et al. 2000). Habitat The species occupies mountainous, rocky, arid to semi-moist habitat, from sea level to 1,500m, but up to 3000m in Africa and 3750m in the Himalayan foothills. It generally occurs in open areas but also occupies woodland. Juveniles often occupy areas near large water bodies (Ferguson-Lees and Christie 2001). Diet The eagle’s prey principally comprises small or medium-sized birds, but it will also take mammals, some reptiles, insects and rarely, carrion (Ferguson-Lees and Christie 2001). Breeding Site The nest is composed of sticks, up to 2m in diameter, located on remote cliff ledges or in a large tree. The nest is re-used in successive years. Breeding occurs from January to July in the west of the range, and from November to September in the Indomalayan region (Ferguson-Lees and Christie 2001).
Since the 1950s the species has declined throughout its range. It was affected by pesticide use in the mid-20th Century, and since then populations have not recovered to their pre-organochlorine levels. The species is persecuted by hunters and pigeon-fanciers in the west of its range and juveniles suffer high mortality from collisions with power lines (Rollan et al. 2010). Declining prey availability, increasing human disturbance and poaching at nest sites, and agricultural intensification are thought to be key factors in the species’ decline (Ferguson-Lees and Christie 2001, Orta et al. 2016).
Conservation Actions Underway
CMS Appendix II. CITES Appendix II. EU Birds Directive Annex I. Bern Convention Appendix II. In France most nests are wardened during the breeding season and in southern France and Catalonia artificial food sources have been successfully provided for some breeding pairs. Research on species demography including juvenile dispersal, mortality and adult recruitment has been undertaken in eastern Spain and southern France (Tucker and Heath 1994).
Conservation Actions Proposed
The implementation of access restrictions and legal habitat protection is required in nesting areas to avoid disturbance and habitat destruction. Dangerous electricity pylons should be modified or buried. Game crops should be used to enhance prey populations, extensive pastoral farming should be maintained and hedges bordering fields preserved. These measures could be promoted in the EU under agri-environmental regulation. Within Europe, undertaking education campaigns with the active involvement of hunting associations and the continuation of research and monitoring, extending into Portugal and eastern Mediterranean countries would help preserve the species (Tucker and Heath 1994).
Text account compilers
Butchart, S., Ashpole, J, Ekstrom, J., Harding, M.
Recommended citation
BirdLife International (2024) Species factsheet: Bonelli's Eagle Aquila fasciata. Downloaded from
https://datazone.birdlife.org/species/factsheet/bonellis-eagle-aquila-fasciata on 24/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 24/11/2024.