Ayres’s Hawk-eagle (Hieraaetus ayresii): Revise global status?

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7 Responses to Ayres’s Hawk-eagle (Hieraaetus ayresii): Revise global status?

  1. James Bradley says:

    My impression from observations in Kenya is that this bird is fairly widespread and not uncommon. It is also adept at colonizing small patches of woodland and small wooded knolls/hills. It is very much the smaller cousin of African Crowned Eagle from an ecological perspective but is absent from forest interior and large expanses of dense forest, instead making use of smaller fragments and lighter woodland. Therefore, the comment that 8.5% of forest in the species range was lost should not be automatically equated with similar declines in the species because true forest is not the principal habitat of this species. The fragmentation of larger forests may actually benefit this species. One aspect of it’s ecology that may offer it some protection is that it is particularly fond of sloping and rolling terrain which is often less attractive for charcoal production and farming because this is often rocky ground. It also makes use of woodlands comprised partly of exotic plantation species (cypress, eucalypt) and in suburban areas that are wooded it seems to persist without difficulties. In Nairobi, for example, over an area of around 400km2, there may be as many 8+ pairs (=~50km2 per pair though only small portion of this occupied). In other parts of the country I have found this bird in quite small patches of habitat (5km2). It is well conserved in numerous protected areas in Kenya and because it does not forage in agricultural lands it is possibly less persecuted and less vulnerable to secondary poisoning than some other raptors, e.g. Brown Snake Eagle, Long-crested Eagle etc.

  2. Warren Goodwin says:

    While never a particularly common visitor to southern Africa, it appears that in this region this species may well have benefited from the gradual increase in suitable mature stands of exotic trees and the availability of feral pigeons as a food source in some urban areas.

  3. Darcy Ogada says:

    I am submitting a compilation of comments below from the following people, which cover Kenya and the Congo Basin:
    Stratton Hatfield
    Shiv Kapila
    Simon Thomsett
    Colin Jackson
    Gael Vande weghe
    Zarek Cockar
    Sidney Shema
    Darcy Ogada

    Of all the large and medium-sized eagles it is likely the most adaptable. Of eight species of eagle found at Eagle Hill, an unprotected area in central Kenya, it was the only species still observed after circa 60 years of habitat loss (Thomsett 2015). It is a well-known breeder in non-native trees in very small patches of forest and in well-wooded suburban environs. Unlike many raptors, it able to breed successfully in areas with high crow densities. It is scarce to uncommon in central and coastal Kenya, but our general sense is that the species is not declining and could even be increasing in some parts of its Kenyan range. This is despite the fact that it is fairly unobtrusive and occasionally misidentified.

    The population size estimated at 670-6,700 mature individuals seems too low for this species across its African range. Its numbers may be underestimated in the Congo basin. It is a common bird from Gabon to central DRC.

    Thomsett, S., 2015. Eagle Hill, Kenya: changes over 60 years. Scopus: Journal of East African Ornithology, 34: 4-30.

  4. Red List Team (BirdLife International) says:

    Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested by so many people in commenting. The window for consultation is now closed. We will analyse and interpret the new information and post a preliminary decision on this species’s Red List status on this page in early July.

    Thank you once again,
    BirdLife Red List Team

  5. Red List Team (BirdLife International) says:

    Preliminary proposal

    Based on available information, our preliminary proposal for the 2021 Red List would be to retain Ayres’s Hawk-Eagle as Least Concern.

    According to the current range map, the area of this species’s resident range is 5,850,542 sqkm. Based on a possible population density of 1 pair/50 sqkm, and 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.

    There is now a period for further comments until the final deadline in mid-July, after which the recommended categorisations will be put forward to IUCN.

    The final 2021 Red List categories will be published on the BirdLife and IUCN websites in December 2021, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  6. Warren Goodwin says:

    Agree with this proposal based on the data provided.

  7. Red List Team (BirdLife International) says:

    Recommended categorisation to be put forward to IUCN

    The final categorisation for this species has not changed. Ayres’s Hawk-eagle is recommended to be listed as Least Concern.

    Many thanks for everyone who contributed to the 2021 GTB Forum process. The final 2021 Red List categories will be published on the BirdLife and IUCN websites in December 2021, following further checking of information relevant to the assessments by both BirdLife and IUCN.

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