Kori Bustards are large, strictly terrestrial birds. Males may reach 18 kg; females are half the size of the males. There are two subspecies. The East African subspecies (Ardeotis kori struthiunculus) has a mottled grayish-buff coloration with dark brown vermiculations. The sides of the crown on the head extend into a black crest. There is a white stripe over each eye. The chin, throat, and neck are creamy white mixed with black bands. The underparts of the bird are buff colored with dark brown vermiculations. The tail has wide bands of grayish brown and white. The primaries, or flight feathers, are also similarly marked. The shoulder area has a checkered black and white pattern. The southern subspecies (Ardeotis kori kori) is similar in appearance, but is slightly smaller withminor plumage differences.
The East African subspecies is found in Ethiopia, Kenya and Tanzania. The southern form is distributed in southern Africa in Botswana, Zimbabwe, Namibia, southern Angola, South Africa, and southern Mozambique. Kori Bustards are birds of wide, open grasslands, and lightly wooded savanna. The subspecies struthiunculus is generally found at low elevations ranging anywhere from 700 to 2000 meters. The subspecies kori can be found in arid savanna areas where trees are scattered intermittently. Both subspecies are fond of areas where the grass is short and where there is a good view of the surrounding area. Migrations in response to rainfall and/or food supply have been recorded, but the species is not migratory in the true sense.
Kori Bustards are omnivorous
birds, although they tend to be more carnivorous than other
species of bustards. Insects form a large portion of their
diet, especially when they are chicks. They also eat a variety
of small mammals, lizards, snakes, seeds, and berries of plants.
They have been observed eating carrion. They are purported
to eat the gum from the Acacia tree. Discrepancy exists however,
as to whether they are eating the gum itself, or the insects
that might be stuck to the gum. Kori Bustards are one of the
few species of birds that drink water using a sucking motion
rather than scooping it up as most birds do.
Kori Bustards are considered to be a polygynous species. Males often gather in loose lek-like formations on top of low hilltops and display for females. During the height of display, the esophagus in the neck of the male is inflated to as much as four times its normal size. The tail feathers are cocked so as to reveal as much of the white underfeathers as possible. The wings may droop down so much that the tips of the primaries touch the ground.
During direct courtship of a female, the male will bow toward her with his neck inflated and bill snapping. He may also emit a low-pitched booming sound. Actual copulation lasts no more than a few seconds, and once over, the male leaves and resumes displaying to attract another female. He plays no part in incubation or in the rearing of chicks. As with all bustards, no nest is made. Rather, the clutch of one to two eggs is laid on the ground in a shallow scrape the female has made. The eggs are pale olive in color with splotches of brown. Incubation is 23-24 days. The chicks are precocial and able to follow their mother around several hours after hatching. They remain with her well after the fledging period, which is at about five weeks. Sexual maturity is reached (at the earliest) at two years.
Kori Bustards are listed on Appendix II of CITES. The distribution of the kori subspecies is becoming fragmented and overall, declining in numbers. Local extinctions have been recorded. The subspecies struthiunculus is faring better where it is widespread in Tanzania, especially on the Serengeti plains. Given the continual habitat destruction from agriculture and development, hunting pressure, and a slow reproduction rate, Kori Bustards do not face a promising future in the wild.
Zoos are now breeding Kori Bustards and studying them to learn more about how to save them in the wild. The National Zoo is working in this effort to help Kori Bustards, by keeping the International studbook for the species. This studbook records all Kori Bustards maintained in zoos and facilities around the world. It is used to help manage the species in captivity by recommending good genetic pairing between birds. The National Zoo recently achieved breeding in this species for the first time in October 1997. The National Zoo is only the third zoo in the United States to breed this species.
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Johnsgard, Paul A.. Arena Birds, Sexual Selection and Behavior. Smithsonian Institution Press, 1994.
Johnsgard, Paul A.. Bustards, Hemipodes, and Sandgrouse,
Birds of Dry Places. Oxford University Press. 1991.