Kori Bustard

The kori bustard is the largest flying bird native to Africa, and the male may be the heaviest living animal capable of flight. A ground-dwelling bird, it occurs from Botswana, Zimbabwe, Namibia, southern Angola, South Africa and Mozambique, with a second subspecies in East Africa from Ethiopia to Tanzania. An opportunistic omnivore, it eats locusts, grasshoppers, dung beetles and other insects, small lizards, snakes and rodents, and plant material such as seeds and berries, and is especially fond of acacia gum. It prefers to run rather than fly. In courtship, males inflate the oesophagus into a white throat balloon, boom and strut with the tail raised.

About the kori bustard

The kori bustard is a huge, ground-dwelling bird of African grasslands and savannas, and the largest flying bird native to Africa. It belongs to the bustard family, a group of long-legged Old World birds, and is one of four species in the genus Ardeotis, which ranges from Africa to India and Australia.

Its scientific name, Ardeotis kori, takes its species name from Kgori, the bird's name in the Tswana language. The male may be the heaviest living animal capable of flight. Typical males weigh 7–18 kg (15–40 lb), and exceptional birds reach at least 20 kg (44 lb). Among bustards, only the male great bustard reaches similar weights, and after the ostrich, the kori is Africa's second-largest bird.

The sexes differ enormously. Females are 20–30 percent smaller in linear measurements and often weigh only a third to half as much as males, averaging around 4.8–6.1 kg (11–13 lb). They also have thinner legs and slimmer necks.

Up close, the kori bustard is beautifully camouflaged. Its body is mostly gray and brown, finely patterned with black and white, and the upper parts and neck are vermiculated in black and grayish buff. A blackish crest sits on the large head above a white eye stripe, and a black collar wraps the base of the hind neck. The neck feathers are loose, which makes the neck look thicker than it is. The eye is pale yellow, the bill long and straight, and the yellowish legs end in three forward-facing toes. The feathers contain light-sensitive pigments called porphyrins that give them a pinkish tinge at the base.

Two subspecies are recognized: the paler Ardeotis kori kori of southern Africa and the boldly patterned "Somali kori," A. k. struthiunculus, of East Africa.

Behavior and diet

Kori bustards spend up to 70 percent of their time on foot. They walk slowly and hesitantly, and when they spot an intruder they often slip away quietly with the head held at an odd 45–60 degree angle. Being so heavy, they avoid flying. A frightened bird runs first and takes off only if pushed, laboring into the air before settling into slow, measured wingbeats, and usually lands again within sight.

They forage mostly in the morning and evening, standing in shade through the heat of the day. The diet is broad. Insects such as locusts, grasshoppers, dung beetles and caterpillars are staples, and the birds also eat lizards, chameleons, small snakes, rodents, bird eggs and nestlings, as well as seeds, berries, roots, bulbs, flowers and wild melons. They love acacia gum, which earned them the Afrikaans name Gompou, or "gum peacock." Unusually for a bird, they suck water up rather than scooping it.

Kori bustards often follow fires or grazing herds to catch insects flushed from the grass. In Tanzania they regularly accompany herds of blue wildebeest. In Botswana's Chobe National Park, carmine bee-eaters sometimes ride on their backs, snapping up insects the bustard disturbs.

Breeding is a spectacle. Males gather at display sites, or leks, and inflate the esophagus up to four times its normal size into a white throat balloon that can be visible up to 1 km (0.6 mi) away. They cock the tail forward over the back like a turkey, droop the wings, raise the crest and give a deep booming "woum-woum-woum" call. Females visit, choose a male, and then raise the young entirely alone.

The female lays one to three eggs, usually two, in a shallow, unlined hollow near a tree, shrub, termite mound or rock. She stays on the nest 98 percent of the time, rarely eating and never drinking, and sometimes drops bits of vegetation on her back for extra camouflage. Chicks follow her within hours of hatching, fledge at 4–5 weeks, and breed at three to four years old. Life is hard for young birds: up to 82 percent die in their first year.

Range and habitat

The kori bustard has two separate populations. In southern Africa it is common in Botswana and Namibia and extends into southern Angola, southwestern Zambia, Zimbabwe, southern Mozambique and much of South Africa. In the northeast it ranges from southeastern South Sudan, Somalia and Ethiopia through Kenya, Tanzania and Uganda. Kenya may hold the largest population of any country.

It lives in open, grassy country, often on sandy soil with short grass near scattered trees or bushes. Typical habitats include plains, arid plateaus, highveld grassland, arid scrub, lightly wooded savanna and semi-desert, in areas that get only 100–600 mm (4–24 in) of rain a year. It avoids dense woodland and forest, partly because such a heavy bird needs open space to take off.

Most birds are resident, but some wander after rain. In Etosha National Park, birds have been recorded moving up to 85 km (53 mi) between seasons. Predators include leopards, caracals, cheetahs, lions, spotted hyenas, jackals and martial eagles.

Conservation status

The kori bustard is listed as Near Threatened on the IUCN Red List. It has a large range and is thought to be declining relatively slowly, but it is now generally uncommon outside major protected areas. The species is listed on CITES Appendix II, and South Africa's 2000 Eskom Red Data Book for Birds lists the southern subspecies as Vulnerable.

Hunting is a long-standing threat. Bustards have traditionally been snared with acacia gum baits, and although no longer classed as game birds they are still sometimes eaten. Habitat loss, worsened by bush encroachment from overgrazing and by farming, is another major problem. Power lines kill many birds: one 10 km (6.2 mi) stretch in the Karoo killed 22 kori bustards in five months. Locust poisons may also be a risk.

The bird is woven into African culture. It appears in the dances, songs and ancient rock art of the San people, Botswana's royalty once reserved it for their own tables, and it is Botswana's national bird.