Cassin's Hawk Eagle

The adult Cassin's hawk-eagle appears as a small eagle, with short rounded wings and a long rounded tail. It has dark brown upperparts, with white spots and a brown tail with three black bars and a broad black subterminal band. The tarsi are white with black streaks, and the underparts are all white or white with black blotches along the sides of the lower breast. It has yellowish-brown eyes, pale yellow ceres and feet and a black bill. Immature and juvenile plumage is strikingly different from that of adults. A brown or rufous head with dusky lores and streaked black on the throat and centre of the crown is typical. The underparts are white and the breast russet with half-concealed blackish spots, while the belly and flanks are marked with dense black spotting. The tail is dark gray with a white tip and dark barring and the dark brown wings have white-tipped secondary feathers. In flight, the juvenile shows pale underwing coverts whereas an adult has dark underwing coverts and a black band along the rear edge of the wing. The immature gains its adult plumage by becoming blacker above and whiter below.

Distribution and habitat

West, central and marginally east Africa; from Sierra Leone east to western Uganda and south through the Congo Basin to northern Angola. Restricted to primary rainforest, A. africana is thought to have been more widespread in the past but its distribution has since contracted with the continued destruction of the Guinea-Congolian Forests. Repeated sightings of individuals in primary rainforest fragments in Kenya's Imenti Forest and the Ndundulu Forest in Tanzania have been interpreted as biogeographical evidence for past links between isolated forests in East Africa and those much further West. Cassin's hawk-eagle's preference for primary forest is so strong that its presence is reduced even in slightly disturbed forest and it is completely absent from secondary forest and open biomes which explains its absence between the forests.

Taxonomy

Cassin's hawk-eagle taxonomy has been in flux ever since it was first described and remains uncertain to this day. Previously, the broader taxonomy of true eagles was based on morphological similarities such as plumage patterns that yielded the 'booted eagle' (eagles with feathered tarsi) and 'hawk-eagle' contained groupings. As such, Cassin's hawk-eagle was formerly allocated to the genera Limnaetus, Phoeoaetus, Cassinaetus, Hieraaetus, and Spizaetus in no particular order.

Conservation status

Cassin's hawk-eagle is currently categorised as Least Concern by BirdLife International and the IUCN. Despite a decreasing population, estimated at 1,000-10,000 individuals, Cassin's hawk-eagles has a large geographic range and its population decline is not severe enough for it to be given Vulnerable status as a species. Due to its reliance on primary tropical forest and the varying rates of destruction of this habitat across Africa, the Cassin's hawk-eagle is regionally threatened and in dire need of population studies to accurately establish the status and effects of human-caused habitat alteration. Thiollay (1985) suggests that lumbering be restricted to removing only small patches of forest to prevent too much degradation, however this strategy is unlikely to be followed, unless enforced, due to the reduced economic gain.