diagnostics
1.2-1.5 m, c. 12.4 kg (male); 1.0-1.2 m, c. 5.7 kg (female). A massive terrestrial bird: the world's largest bustard, and one of the heaviest flying birds. Sexes differ in size and slightly in plumage colouration. Crown black, with paler median stripe, ending in long nuchal crest that can be flared up when excited. Face speckled grey, with white supercilium, lores and chin, and dark moustachial stripe. Neck finely barred grey and white; neck hugely inflated during courtship display. Underparts white. Dark collar at base of neck. Mantle, scapulars, tertials and inner wing coverts brown, finely vermiculated with dark brown. Greater coverts and outer median coverts white with black sub-terminal marks, forming checkered patch visible on folded wing. Flight feathers grey brown, with multiple white bars. Tail grey brown, whiter towards base, overlaid with several dark bars. Bill pale horn. Eyes lemon-yellow. Legs yellow to dark cream. Female similar to male, but with less distinct facial markings. Juvenile similar but with shorter crest, more freckled upperparts, and paler eyes.
trophic
The Kori Bustard is usually found alone or in small groups (Allan and Osborne 2005), although as many as 46 individuals have been recorded feeding next to each other in an open pan (Allan 1997). The species inhabits fairly dry, open savannahs, within the 100-600 mm rainfall zone, as well as Nama Karoo dwarf shrublands and occasionally western grasslands where clumps of trees on tree-lined watercourses provide shade and shelter (Allan 1997). Adult and sub-adult males may disperse up to 120 km outside the breeding season, occupying home ranges of 8.6-66.3 km2 (Osborne and Osborne 1998), while juvenile females remain near their natal areas; young remain with their mother until the start of the next breeding season (Hallager and Boylan 2004), and females with young typically remain in relatively small home ranges, e.g. 1.1-14.9 km2 in a study at Etosha National Park, Namibia (Osborne and Osborne 1998). The diet is catholic and includes various invertebrates (grasshoppers, locusts, beetles, armoured ground crickets, termites, caterpillars, solifuges, scorpions and snails), small vertebrates (lizards, chameleons, snakes, bird's eggs and nestlings, and small rodents) and a vegetable component (flowers, leaves, seeds, fruits, pods, roots, bulbs, wild melons, grass and vachellia (acacia) gum) (Chiweshe and Dale 1993, Allan and Osborne 2005). The species is a polygynous, solitary nester (Allan 1997), with the breeding season lasting from July to April. A generation length of approximately 16 years is provided by BirdLife International (2014) although this is based on life history parameters of the extra-limital, but similar-sized Great Bustard, Otis tarda.
