Ayres's Hawk-eagle Hieraaetus ayresii


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 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). 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). For these reasons the species is evaluated as Least Concern.

Population justification
According to the current range map, the area of this species’s resident range is 5,850,542 km2. Based on a possible population density of 1 pair/50 km2 (J. Bradly in litt. 2021), and given that only a small portion of its range is likely to be occupied (assumed here at 10-20%), the population may number 23,402 – 46,804 mature individuals. In the absence of other data, the population is therefore placed in the band 20,000 – 49,999 mature individuals.

Trend justification
During the years 2001-2019, 8.5% of forest cover was lost across this species's range (Global Forest Watch 2021), equating to a loss of 10% over three generations (23.4 years [Bird et al. 2021]). During the years 2016-2019, 3% of forest cover was lost (Global Forest Watch 2021), equivalent to 16% when projected forward over three generations. However, this species prefers smaller woodland fragments and is absent from large areas of dense forest (J. Bradley in litt. 2021). It can also utilise plantations, as well as savannas and urban areas, therefore it is assumed to decline at a slower rate that forest loss alone. It may also be increasing in Kenya (S. Hatfield, S. Kapila, S. Thomsett, C. Jackson, G. Vande weghe, Z. Cockar, S. Shema and D. Ogada in litt. 2021), and in urban areas it may have benefited from the increase in mature stands of exotic trees and the availability of feral pigeons as prey (W. Goodwin in litt. 2021). 

The species is subjected to direct persecution in the south of their non-breeding range (Kemp and Boesman 2013). While the rates of persecution are unknown, this is a small part of the range, and therefore the overall rate of decline is suspected to be <20% over three generations.


The species is vulnerable to habitat loss, degradation of woodland and direct persecution (due to its habit of preying on racing pigeons and other birds [Hartley and Mundy 2003]) in parts of its range (Kemp and Boesman 2013, Global Raptor Information Network 2015). It may also be vulnerable to pesticide contamination (Global Raptor Information Network 2015).

Conservation actions

Conservation Actions Underway
This species is listed under CITES II and CMS Appendix II.


Text account compilers
Clark, J.

Ashpole, J, Bradley, J., Butchart, S., Cockar, Z., Dowsett, R.J., Ekstrom, J., Goodwin, W., Harding, M., Hatfield, S., Kapila, S., Ogada, D., Shema, S., Thomsett, S. & Vande weghe, G.

Recommended citation
BirdLife International (2022) Species factsheet: Hieraaetus ayresii. Downloaded from on 19/01/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 19/01/2022.