Bio Facts: Bustard, Kori
Two separate populations: one ranges from Zambezi southwest to the Cape, and the other ranges from the Nile to the Horn of Africa.
Grasslands, arid plains, semi-deserts, and light savannas.
A rather sizeable bird, kori bustard has a long neck, long legs, with a robust body. Males may weigh nearly 40 lbs., females are half that weight. Males and females are alike in plumage: mottled in color with a white stripe over each eye. The chin, throat, and neck are creamy white mixed with black bands. The underparts are buff colored with dark brown irregular fine lines (vermiculations). The tail has wide bands of grayish brown and white. The primary flight feathers are similarly marked. The shoulders have a checkered black and white pattern.
In captivity, records indicate at least to 25 years.
In captivity, the youngest recorded age of first reproduction occurred in the fifth year.
In the wild, kori bustards eat chiefly insects and their larvae, especially grasshoppers and dung beetles, reptiles, small rodents, carrion and vegetable matter including seeds, roots and wild melon. Kori bustards have also been known to eat the gum of the Acacia tree. In the Zoo, they are fed galliform mix, bird of prey diet, insects, mice, and rats, chicks and fruit.
Uncommon to locally common, but generally declining.
All bustards are strictly ground dwellers. In Africa, the bustards are to the savannas what cranes are to the marshes. Kori bustards are omnivorous and tend to be more carnivorous than other species of bustards. Insects form a large part of their diet. Kori bustards have been observed eating carrion and have been known to attend brush fires, scavenging on insects killed in the fires. Koris have been observed eating carrion, too.
Kori bustards are one of the few birds known to drink water using a sucking action rather than a scooping action like most other birds.
Kori bustards are found solitary, in pairs or small loosely associated groups. Reluctant to fly, koris walk rapidly with long strides. During the hottest hours of the day, they can commonly be found resting in tree shade. In East Africa, koris make frequent trips to waterholes. This population also appears to migrate in response to rainfall or food supply (especially to follow bush-fires or wildebeest migrations). In southern Africa, some koris move east or southeast to winter at lower levels, and in former times, they migrated on foot in very large numbers.
The mating system of the kori bustard is unclear. They are considered a polygynous species (a male will pair with two or three females). Captive birds, however, have been observed to breed in pairs, suggesting that a monogamous system may also exist. No male bustard has ever been observed to incubate eggs. No nest is made; rather the eggs are laid on the ground in a shallow scrape made by the female. After an incubation period of approximately 23 days, the female with male sometimes attending cares for chicks. Walking chicks keep under the female, immediately behind her legs. In addition to receiving food from their mother, chicks feed on insects at their head height rather than from the ground.
Courtship behavior: displaying male struts back and forth over a particular area (commonly a low hilltop) with tail cocked forward. Occasionally, he stands very upright and gradually inflates his neck (up to four times it normal size) until it forms a white puffy ball, bulges his cheeks, erects his crest feathers, holds his bill up at an angle and opens it, fans and cocks his tail at various angles exposing the white undertail coverts, and droops his wings so that the primaries touch the ground. He may then strut about or stand still, often staying near a landmark, and when dilation of his neck reaches it maximum, he calls, bill snapping open and shut with his neck vibrating. During courtship, the male walks slowly around the female, or stands within 30 feet of her, bowing with body tilted forward, neck inflated, head never reaching below the level of the shoulders. The male also emits a low-pitched booming noise audible over great distances. Displaying males have been observed offering 2.5-foot snakes to females in the wild. In captivity, males have been observed provisioning females, once both begin feeding. Copulation only lasts a few moments. After which wild males resume displaying in order to attract another female.
What is emerging with increasing certainty, however, is that the majority of bustard species establish no true pair bond, depending instead on “dispersed lek” behavior. Males advertise themselves often at traditional individual sites, sometimes in moderately clumped groupings while preserving distances of one to several hundred meters between each other.
Kori bustards are generally silent. When alarmed, however, both sexes emit a loud bark. In a defensive display, the bird bows forward, lifts its tail feathers, and spreads and inverts its wings, making itself look larger than any potential predator.
Sun bathing is practiced. Kori bustard feathers contain light sensitive porphyrins that give the feathers a pink tinge at the base.
Bustards have no crop, but their powerful gizzard, long “blind gut” (cecum) and their habit of taking up quantities of grit assist the digestion of the food they consume.
Bustards have lost both the hind toe and the preen gland that most other birds possess. To keep clean, they produce a powder down. Instead of using oil to keep themselves clean, they use dust baths. These losses, together with their camouflage pattern, appear to be adaptations for their terrestrial environment.
A symbiotic relationship has been observed between Kori bustard’s and Carmine bee-eaters. The bee-eaters are known to ride on the backs of foraging kori bustard, flying up to eat any insects disturbed by the kori’s activities. In return, the bustards may receive some form of predator detection service from the bee-eaters. Kori bustards are also found in large herds of hoofstock, such as wildebeest, which may provide additional predator detection.
The order name, Gruiformes, comes from the Latin grus, crane, and forma, form. This is a very ancient order of birds whose fossil history goes back to the Eocene Period (60 million years ago). The order has sometimes been referred to as “a group of misfits” because it includes such a mixed bag, the members of which do not seem to belong anywhere else.
The name bustard, by derivation, roughly means “the bird that walks.”
The bustards are a homogenous family, although there are differences in structure, color, size, and behavior.
Bustards are little known, largely because of the difficulty in studying nervous, well-camouflaged, slow-breeding birds that tend to desert their nests if once alarmed.
The first facility in the world to successfully breed Kori bustards in captivity was the Nurnburg Zoo, Germany, in 1989. Today, the majority of kori bustards in captivity (historically 91% of captive population) can be found in three countries – United States, United Arab Emirates, and Germany.
In Afrikaans, the kori bustard is called Gompou or “gum-eating bird” because it has been observed eating the gum of the Acacia tree.
Kori bustards figure in dances and songs of the Bushmen of Botswana. Drawings have been found in caves depicting this species.
The bustard’s susceptibility to disturbances is a major reason for their decline, especially in northern parts of their distribution where grasslands are coming under pressure from advancing agriculture.
Jacksonville Zoo History:
The kori bustard is a recent arrival in the Zoo’s animal collection with the first ones exhibited in September 2000.