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 ten 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 ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
Behaviour This is an afrotropical species (17°N to 35°S), common to abundant throughout its range except in waterless areas. It is generally sedentary but can be nomadic in response to resource shortages (e.g., drought, flood or prey scarcity), and has been recorded traveling up to 200km from the natal site (Ferguson- Lees and Christie, 2001). Habitat The species occupies a range of aquatic habitats from sea level to 4000m, ideally areas of calm water, such as swamps, lakes, rivers, floodplains and estuaries. Juveniles that are dispersing can cross vast dry areas and will roost and feed on carcasses en-route (Ferguson- Lees and Christie, 2001; del Hoyo et al., 1994). Diet The species’ diet consists primarily of fish, but it will also take other available taxa as well as carrion when prey is scarce. Juveniles are known to feed at large mammal carcasses alongside vultures and Tawny Eagles (Ferguson- Lees and Christie, 2001). Breeding Site The species nests near water, in tall acacias or other suitable trees, and occasionally on rock outcrops. Nests are up to 1.5m in diameter and are composed of sticks and papyrus, lined with rush heads and occasionally, weaver nests. Breeding can occur at any time within Equatorial regions, but spans April - October in southern Africa; June - December in the east; and October – April in the west (Ferguson- Lees and Christie, 2001).
The species is not known to be directly persecuted by humans, even though it is very numerous and probably a direct competitor for fish. Neither is it particularly affected by habitat loss. In some regions a build-up of organochlorine pesticides in water bodies and therefore in their fish prey, could result in eggshell thinning. This has been recorded in South Africa (Ferguson- Lees and Christie, 2001) and Zimbabwe (del Hoyo et al., 1994) but has not yet had any significant impact on the population.
Text account compilers
Ekstrom, J., Butchart, S., Harding, M.
BirdLife International (2020) Species factsheet: Haliaeetus vocifer. Downloaded from http://www.birdlife.org on 20/10/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/10/2020.