Family: Accipitridae
Genus: Terathopius
Species: T. ecaudatus

Bateleurs are striking, medium-sized eagles with impressive flying displays. They live across regions of sub-Saharan Africa and as far north as the Arabian Peninsula, occupying open woodland and savanna. They form a clade with Circaetus pectoralis (Black-Chested Snake Eagle) and Circaetus gallicus (Short-Toed Snake Eagle), in addition to being closely related to Pithecophaga jefferyi (Philippine Eagle).

Physical Description:

Bateleurs have a black head, neck, breast, belly, and thighs, and the mantle, rump, tail, and undertail are brown to chestnut. The head and feet are bright red, though the exact hue depends on the bird’s mood. A red eye ring surrounds the dark brown to black eye, and the beak is yellow with a black tip. The color of the wings varies depending on its gender; females have more gray on their wings than males, white secondary feathers with black tips, a black and white underwing, and a narrow trailing edge. Males, on the other hand, have black secondary feathers, pale gray shoulders, and a thick black trailing edge.

All Bateleurs have an extremely short tail, which is easily visible from a distance. They also have a tendency to tip back and forth in flight, hence their name: "bateleur" is French for tight-rope walker, referring to the way the bird seems to catch its balance in midair. They are capable of flying up to 320 km a day and can reach speeds of 80 kmh.

Juveniles are a brown-chestnut color with dark primary feathers. The feet are pale pink, the face is bluish-gray—almost green—and the eyes are brown.

They are mostly silent birds, but when they do call, it is a short "kau kau kau", usually followed by "koaagh koaagh". At the same time, they raise half-open wings as part of a territorial display.

Their lifespan is around 25 years.

Habitat and Distribution:

Bateleurs occur in savanna, grassland, other such open areas, and some woodland. They do not inhabit lowland forest area or wetlands, but will be seen in those areas when foraging. They live from 0-4,500 m above sea level, but most often below 3,000 m.

They live throughout sub-Saharan Africa, from western Africa to the eastern part of the continent and South Africa. Adults remain in the same area throughout the year, but juveniles will travel large distances to find new territory where there are no adults. Juveniles have been known to gather in the hundreds along the Zambezi River in Zimbabwe and in northern Botswana during the late wet through early dry season. Bateleurs of all ages gather in Kgalaladi National Park in the winter and Kruger National Park in summer. Protected areas are some of the last places Bateleurs inhabit—they have been eliminated from and/or abandoned 80% of their former range. There are an estimated 10,000-100,000 individuals over 28,000,000 km².

Diet and Hunting:

They are scavengers, although they do catch some live prey. Many small animals make up the bird’s diet, including rodents, birds (such as pigeons, doves, hornbills, and even other raptors), lizards, fish, insects, and frogs. Bateleurs are also known as the African Snake Eagle, and is one of the few animals that eats venomous snakes. When hunting it will puff itself up, so if the snake strikes it will only get a mouthful of feathers.

To hunt, they will fly as low as 45 m above the ground to look for food, spending 8-9 hours on the wing a day, over a range of up to 200 km². They search for carcasses from the air and have been known to follow roads in search of animals killed by traffic. Bateleurs are attracted to veld fires; they snatch up animals that died in the heat or catch ones that are trying to escape. As with other eagles, kleptoparasitism (stealing food from other animals) is not uncommon behavior.

Reproduction:

The breeding season is from September-May in western Africa, all year-round in eastern Africa, and December-August in southern Africa. Breeding displays consist of courtship both from the air and sometimes from the ground; when in the air, they perform aerial stunts, from somersaults to 360 degree rolls. Bateleurs have also been seen executing aerial feats where the male dives and chases the female, who rolls over in midair and presents her talons. Pairs are monogamous.

The nest is built in around six weeks and is made of a stick platform 45-100 cm wide and 25-100 cm deep. It is cup-shaped and lined with green leaves. Nests are usually set in the fork of a tree with a leafy canopy above, 7-25 meters above the ground. A single egg is laid, and it is incubated by both parents for 52-59 days. The parents also take turns caring for the offspring, defending them from potential threats such as Bubo lacteus (Verreaux's Eagle-Owl). Fledging takes 93-194 days and they young are completely independent around four months after that. They reach full maturity after 5-6 years.

Unpaired, immature Bateleurs will sometimes hang around a nest site if the breeding pair tolerates their presence, and they will help defend and guard the area.

Conservation:

Bateleurs have been listed as Near Threatened by BirdLife International. The population is decreasing and their habitat is shrinking, and they are now restricted to protected areas having been eliminated from farmland in South Africa. They are also under threat from pesticides, poisoned bait left for jackals, and trapping for international trade.

Taxonomy:

Based on nucleotide sequences, Circaetus pectoralis (Black-Chested Snake Eagle), Circaetus gallicus (Short-Toed Snake Eagle), and Terathopius ecaudatus have been found to form a monophyletic clade. T. ecaudatus is also closely related to Pithecophaga jefferyi (Philippine Eagle).

The name "Bateleur" comes from the French word for tight-rope walker. The scientific name is derived from the Greek words teras, which means "meteor", or teratos, which means "marvel". Opos is Greek for "appearance", and ecaudatus means to lack a tail in Latin.

Other Names:

African Snake Eagle, Pine Eagle/Conifer Eagle (due to the appearance of its feathers), Berghaan (Afrikaans), Gøglerørn (Danish), Goochelaar (Dutch), Klounkotkas (Estonian), Liitokotka (Finnish), Aigle Bateleur, Bataleur des savanes (French), Gaukler (German), Lodda (Icelandic), Falco giocolier (Italian), Darumawashi (Japanese), Sipupa (Kwangali), Raudonskruostis gyvatedis (Lithuanian), Gjøglerørn (Norwegian), Kuglarz (Polish), Águia-bailarina (Portuguese), Águila Volatinera (Spanish), Kuyruksuz kartal (Turkish), iNgqungqulu (Zulu).

Video of a Bateleur:

References:

http://www.animalphotos.me/bird7-bat.htm
http://www.arkive.org/bateleur/terathopius-ecaudatus/
http://aviary.owls.com/bateleur_eagle/bateleur_eagle.html
http://www.biodiversityexplorer.org/birds/accipitridae/terathopius_ecaudatus.htm
BirdLife International (2012) Species factsheet: Terathopius ecaudatus. Downloaded from http://www.birdlife.org on 05/28/2012.
Global Raptor Information Network. 2011. Species account: Bateleur Terathopius ecaudatus. Downloaded from http://www.globalraptors.org on 28 May. 2012
BirdLife International 2009. Terathopius ecaudatus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. www.iucnredlist.org. Downloaded on 28 May 2011.
http://www.peregrinefund.org/subsites/explore-raptors-2001/eagles/bateleur.html
Ferguson-Lees, James, and Christie, David A. Raptors of the World. Houghton Mifflin Company, 2001.
http://www.sa-venues.com/wildlife/birds_bateleur.htm
http://www.stlzoo.org/animals/abouttheanimals/birds/vultureshawkseagles/bateleureagle.htm
http://www.travelbutlers.com/safari/wildlife-guide/bateleur-eagle.asp
http://www.wildwatch.com/living_library/birds-1/bateleur
http://world-bird-sanctuary.blogspot.com/2008/03/education-spotlight-bateleur-eagle.html