Bateleur

The bateleur (Terathopius ecaudatus), sometimes called the bateleur eagle, is a medium-sized raptor belonging to the Accipitridae family. It is generally seen as a kin of the snake eagles and falls under the subfamily Circaetinae. This bird is the sole species within the genus Terathopius and might be the inspiration for the "Zimbabwe Bird," the national symbol of Zimbabwe. Adults are mostly black, with chestnut coloring on the mantle, rump, and tail. They also have gray patches along the leading edges of their wings—extending to the secondaries in females—and bright red cere and feet. Males show white greater coverts that contrast with black remiges, while females have gray patches on the underwing primaries and black wingtips. Juveniles look quite different, being largely dull brown with some paler feather scaling. All bateleurs have notably large heads for their size, small bills, big feet, short legs, long bow-shaped wings, and uniquely short tails—adults’ tails are even shorter than those of juveniles.

This species lives across much of Sub-Saharan Africa and barely reaches into Arabia. It favors somewhat open landscapes like savanna with scattered trees and open dry woodland. In terms of life history, it is an unusual bird of prey with a flexible, generalist diet that includes plenty of carrion but also a wide range of live prey—from small mammals and reptiles to surprisingly large ones, as well as generally small birds. Bateleurs are highly aerial, spending much time soaring and often flying with exaggerated, showy movements, possibly when excited or angry. They build a fairly small but sturdy stick nest in a large tree and lay just one egg. Although aggressive in other situations, they are easily scared off their nest, making them very vulnerable to nest predators, including humans, and leading to frequent nest failures. It can take seven to eight years to reach full maturity, possibly the longest maturation period of any raptor. The species has long been known to be declining sharply in overall numbers and is now mostly limited to protected areas. The IUCN currently lists the bateleur as Endangered, mainly due to human-caused threats like habitat destruction, pesticide use, and persecution.

**Taxonomy and etymology** Genetic studies have confirmed the bateleur as a proper member of the subfamily Circaetinae, the snake or serpent eagles. Its outward resemblance to snake eagles had long led authors to infer this relationship. Specifically, it was thought to be closest to the large *Circaetus* snake eagles. A genetic study based on cytochrome b gene sequences supported this, showing that the bateleur and the short-toed snake eagle (*Circaetus gallicus*) form a monophyletic clade. Despite differences in plumage patterns, the two genera share similarities in food, feeding behavior, and breeding biology. However, Lerner and Mindell (2005), using molecular sequences from two mitochondrial genes and one nuclear intron, pointed to an unexpected close relationship between the bateleur and another “aberrant” member of the Circaetinae—the Philippine eagle (*Pithecophaga jefferyi*)—which differs greatly in appearance and life history. Chromosome banding studies have also found a relatively recent genetic link between bateleurs and Old World vultures.

The common name “Bateleur” comes from French, meaning “street performer.” The scientific name combines *teras* (Greek for “marvelous”), *ops* (Greek for “face”), *e* (Latin for “without”), and *caudatus* (Latin for “tail”). French naturalist and explorer François Levaillant gave the bird its common name. The original scientific name was *Falco ecaudatus*, assigned by François Marie Daudin, before the concept of separate genera for birds of prey was developed (and before falcons were known to be unrelated to many other diurnal raptors).

**Description** The bateleur stands out for its unique shape and plumage, sharing some anatomical traits with both snake eagles and vultures. It has a thick neck and a very large, hooded head with a proportionally short bill, though the bill is covered by a large cere. The hood is also present in snake eagles but is less obvious. When perched, adults look oddly stubby, with short legs and an exceptionally short tail—possibly the shortest relative to body size of any raptor. Their posture while perched is very upright, making them appear tall on the ground despite their short legs. Even at rest, the body is dominated by the exceptionally large wings, which have about 25 secondary feathers—perhaps more than any other raptor.

Adults usually have chestnut coloring on the mantle, back, rump, and tail, including the undertail coverts. Adult males are mostly black with gray shoulders that look edged in white when freshly molted. Adult females differ by having gray-brown (not black) greater coverts and black-tipped gray (not black) secondaries. Up to 7% of adults show a “cream morph,” where the chestnut tail remains but other chestnut areas are largely replaced by cream to pale brown. This morph may be slightly more common in drier regions. The bare parts of adults are very striking: the cere, bare facial skin, and feet are bright red.