The Brown Snake Eagle, with its scientific name Circaetus cinereus, is a robust bird of prey belonging to the Accipitridae family. It is characterized by its predominantly dark brown plumage, which may exhibit a purplish sheen under certain lighting conditions. The wings are similarly colored, save for the contrasting whitish-grey unmarked flight feathers. A relatively short tail displays brown and grayish cream bars, visible during flight.
This medium-sized eagle is distinguished by its large head and bare legs, setting it apart from other brownish eagles in Africa. Juveniles resemble adults but may show sparse white feather bases, with southern individuals displaying more pronounced white speckling. The species can be confused with a juvenile Bateleur in poor light, but the Bateleur has more varied coloration, brown eyes, a shorter tail, and shorter legs.
The Brown Snake Eagle inhabits open woods and wooded savanna, often favoring areas with gulleys or wooded hillocks that interrupt flat terrain. It shows a preference for more densely wooded areas compared to related snake eagles and can be found from sea level up to elevations of 2,000 meters.
Widely distributed across Africa, this species is found from southeastern Mauritania and Senegal to Guinea, Sierra Leone, and across to southern Chad, Sudan, South Sudan, and into southern Somalia, Kenya, Uganda, and the southern Democratic Republic of the Congo. Its range extends down through southern Africa to parts of Namibia, Botswana, Zimbabwe, and northeastern and eastern South Africa.
The Brown Snake Eagle is a solitary bird, with breeding pairs rarely seen together. It exhibits territorial display flights, which can escalate to erratic butterfly-like movements and, in intense situations, talon interlocking and cartwheeling. This species is not migratory but may exhibit nomadic tendencies.
Its vocalizations include a hoarse, guttural "hok-hok-hok-hok," often used in territorial displays, and a softer "kwee-oo" likely serving as a contact call at the nest.
Breeding occurs from November to July in the northern part of its range and mainly from December to July in Zimbabwe and February to October in Kenya. Nests are relatively small and placed in flat-topped trees or on electric pylons. A single egg is laid and incubated primarily by the female for about 50 days. The juvenile remains in the nest for 60-100 days before fledging.
The Brown Snake Eagle may be confused with the juvenile Bateleur or other medium-sized brown eagles, but its large head, bare legs, and specific tail barring help differentiate it.
This eagle preys predominantly on snakes, both venomous and non-venomous, using its thick-skinned legs as protection against bites. It hunts from perches or hillocks, often decapitating large snakes before bringing them to the nest. Alternate prey includes monitor lizards, toads, francolins, guineafowl, chickens, rats, and possibly other mammals.
The Brown Snake Eagle is classified as Least Concern by the IUCN, with a broad range and a presence over 23.3 thousand square kilometers. Although it may be naturally scarce and potentially declining, it does not currently require immediate conservation attention.