The brown snake eagle (Circaetus cinereus) is a fairly large species of bird of prey in the family Accipitridae.

A very solitary bird, the brown snake eagle has a prolonged breeding cycle and raises a single eaglet.

[1] Although it is not migratory, brown snake eagles may be somewhat nomadic, with cases of birds on territories stretching up to 200 km (120 mi) apart.

[2] Their plumage about the body is entirely a fairly dark, hazel brown, with some claims of a purplish sheen in certain light conditions.

[7] The brown snake eagle's call is a hoarse, guttural hok-hok-hok-hok, usually uttered in territorial displays at conspecifics and sometimes culminating in a crowing kaaww.

[9] Even more impressive accounts are known of this species hunting adult black mambas, including specimens measuring up to at least 2.8 m (9 ft 2 in).

[2][4][8] Alternate prey is known to have included monitor lizards, toads, francolins, guineafowl and chickens as well as rats and perhaps other mammals.

[2][4] Breeding takes places in November to July in northern part of range and, although potentially in nearly any month, mainly December-July in Zimbabwe and February-October in Kenya.

[4] A single egg clutch is laid and is incubated mainly by the female for approximately 50 days (quite long for an eagle of this size).

[4][8] This species is somewhat scarce and is possibly declining overall per the IUCN but it is persisting fairly strongly over a large range, that includes 23.3 thousand square kilometers.