Crowned hawk-eagle  (Stephanoaetus coronatus)

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (4).

The crowned hawk-eagle is one of the largest and most powerful eagles in Africa (5) (6). A fairly colourful bird, the head, back and wings are black or dark brown, the breast is cream or reddish, with distinctive black mottling or barring, and there is a long crest on the head which can be raised and which gives the species its common name (2) (3) (5). The tail is long and boldly marked with three black bands (2) (3), and in flight the broad, rounded wings (2) (3) show a reddish underside, with white flight feathers that are clearly marked with three black bands in adult males and two in adult females (5) (7). The feet are large, yellow and very powerful, with formidable talons, and the legs bear barred, feathery “boots” right down to the ankles. The beak is also large and strong, with a conspicuous orange gape-flange (yellow in juveniles), but a dark grey cere. The eyes are a piercing pale yellow (3) (5). The female crowned hawk-eagle is larger than the male, and has heavier marking on the breast and a smaller crest (2) (3). The juvenile is distinct, being pale grey-brown above, with white scale-like edges to the feathers, a grey-brown tail, which has four dark bars in males and three in females, and a white head and underparts (3) (5). During its first few years, the juvenile crowned hawk-eagle gradually becomes darker and gains its black markings, but does not achieve full adult plumage until its fourth or even fifth year. Fledglings have grey eyes, which turn brown and then yellow as the bird matures (3) (7) (8).

The crowned hawk-eagle is quite a vocal bird (3) (5) (9), producing a penetrating and far-carrying keeoowee-keeoowee-keeoowee call during display flights (3) (5) (9). Females use a khoi-khoi-khoi call, often from the nest (5), as well as a shrill kwee-kwee-kwee when the male approaches with food, a call which is also used by the young (3).

The crowned hawk-eagle has a relatively patchy distribution across sub-Saharan Africa, from Senegal to Liberia, east to Sudan and Ethiopia, and south to Angola, Zambia, Zimbabwe, Mozambique and South Africa (2) (3) (10).

The crowned hawk-eagle inhabits forest and dense woodland, including rainforest, riverine forest and montane forest, up to elevations of at least 3,000 metres (2) (3). It may also be found in plantations and in remnant forest patches, and may sometimes move into surrounding secondary forest or dry savanna to forage (2) (3) (5).

The crowned hawk-eagle is a formidable predator, capable of killing prey up to several times its own weight (2) (3). Primates usually make up the bulk of the diet (6) (11) (12), though other mammals are also taken, including small antelopes, rodents, hyraxes and mongooses, as well as large lizards, birds such as hornbills, guineafowl and pigeons, and occasionally carrion (2) (3) (12). The crowned hawk-eagle typically hunts by dropping onto prey from a perch, though it may also snatch tree-dwelling prey in flight, or knock it to the ground (2) (3). The largest prey is dismembered on the ground and pieces may be cached in nearby trees and eaten over several days (2) (3) (5). Crowned hawk-eagle pairs sometimes hunt co-operatively and will share cached food (3).

Courtship in the crowned hawk-eagle involves a noisy aerial display in which the bird, usually the male, performs a series of undulating dives and upward swoops. On being joined by the female, the male may dive, upon which the female rolls and the pair may lock talons and cartwheel through the air (3). Nesting season varies with location (2) (3), and the nest is usually built in the main fork of a large tree, although it may rarely be built on a cliff when no large trees are available (13). A massive structure, it may measure up to two and a half metres across and three metres deep, and is built with sticks and lined with sprays of green leaves. The breeding pair may use the same nest for many years. One to two eggs are laid, and hatch after an incubation period of between 48 and 51 days. When two eggs hatch, the elder chick always kills its younger sibling within a few days, so that only one chick is raised (2) (3) (5). Fledging occurs after 90 to 125 days, but the young crowned hawk-eagle is dependent on the parent birds for up to another 350 days, meaning the crowned hawk-eagle is usually only capable of breeding every other year (2) (3) (14).

The crowned hawk-eagle has a large distribution and is not currently considered at risk of extinction (10). However, its populations are thought to be in decline (10), and the species is under threat from deforestation and from overhunting of its prey, and is now rare in many parts of West Africa (2) (3). The crowned hawk-eagle also suffers persecution because of its size, reputation, and potential for taking small livestock, with birds being shot or trapped or the nests destroyed (2) (3). However, some foresters actually welcome this eagle and protect its nesting sites because it is considered beneficial for controlling mammals which may damage young trees (3).

International trade in crowned hawk-eagles should be carefully monitored and controlled under the Convention on International Trade in Endangered Species (CITES) (4), and the species is also listed under Class A of the African Convention on the Conservation of Nature and Natural Resources, meaning that a high level of authorisation is required before the crowned hawk-eagle can legally be killed or captured, and then only in restricted circumstances (15). The crowned hawk-eagle is found in a number of protected areas throughout its range, including Mount Kenya National Park in Kenya (16), Kibale National Park in Uganda (12), and Taï National Park, Ivory Coast (14) (17). Although not currently considered threatened in most areas, it is thought that the long-term future of the crowned hawk-eagle may increasingly rely on these forested reserves (3).

View information on this species at the UNEP World Conservation Monitoring Centre.

To find out more about the crowned hawk-eagle see:

• BBC Wildlife Finder:
  http://www.bbc.co.uk/nature/species/Crowned_Eagle

For more information on the conservation of eagles and other raptors, see:

• Eagle Conservation Alliance:
  http://www.eagleconservationalliance.org/
• The Peregrine Fund:
  http://www.peregrinefund.org/default.asp

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org