Justification of Red List Category
This species has an extremely 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). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over 10 years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in 10 years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
In Europe, the breeding population is estimated to number 17,600-20,900 breeding pairs, equating to 35,100-41,800 mature individuals (BirdLife International 2015). Europe forms approximately 34% of the global range, so a very preliminary estimate of the global population size is 103,000-123,000 mature individuals, although further validation of this estimate is needed. It is placed in the band 100,000 to 200,000 mature individuals.
The population is suspected to be stable in the absence of evidence for any declines or substantial threats. The European population is considered Stable (BirdLife International 2015). However declines have been reported in West Africa (Thiollay 2007).
Behaviour Birds breeding in the Palearctic are migratory, with the population in South-East Asia resident. Most migrants winter in tropical North Africa, with some eastern birds moving to the Indian Subcontinent (del Hoyo et al. 1994, Ferguson-Lees and Christie 2001). Migrants move south between August and November, and north between February and May (Ferguson-Lees and Christie 2001). Birds are usually observed singly or in pairs, even on migration, though migrants will sometimes form groups of up to 12 (Snow and Perrins 1998, Ferguson-Lees and Christie 2001). They soar at c.20-100 m above the ground (Brown et al. 1982). Habitat It uses a variety of habitats within warm temperate and tropical environments, and is recorded up to 2,300 m (del Hoyo et al. 1994). Diet It specialises in feeding on reptiles, particularly snakes (del Hoyo et al. 1994). Breeding site The nest is almost always built relatively low in a tree (del Hoyo et al. 1994). Management information Although occurring in many habitats, the species always requires some degree of tree cover (del Hoyo et al. 1994).
The species suffered a marked decline in northern Europe in the 19th-20th centuries, due to habitat loss and persecution (Snow and Perrins 1998, Ferguson-Lees and Christie 2001). In Europe, changes in agriculture and land use have reduced the extent of suitable hunting habitat. In addition snake populations have been reduced by increased cultivation of monocultures, hedge destruction, use of pesticides and the abandonment of traditional farmland and subsequent afforestation. Habitat fragmentation in Europe has resulted from forest fires and road construction. It still suffers from shooting on Malta (del Hoyo et al. 1994). Nest destruction and powerlines represent additional threats (Tucker and Heath 1994). It is also very highly vulnerable to the effects of potential wind energy development (Strix 2012). In its West African range, the species is vulnerable to habitat degradation through wood harvesting and overgrazing as well as exposure to pesticides (Thiollay 2007).
Text account compilers
Khwaja, N., Temple, H. & Ashpole, J
BirdLife International (2019) Species factsheet: Circaetus gallicus. Downloaded from http://www.birdlife.org on 15/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 15/11/2019.