An adult male is brown above, barred with blackish colouration, and white below, with a long grey neck and head. His breast and lower neck sides are chestnut and there is a golden wash to the back and the extent of these bright colours tending to increase as the male ages. In the breeding season, the male has long white neck bristles, which measure up to 12?15 cm (4.7?5.9 in) in length, continually growing from the third to the sixth year of life. In flight, the long wings are predominantly white with brown showing along the edges of the lower primary and secondary feathers and a dark brown streak along the upper-edge of the wing. The breast and neck of the female are buff, with brown and pale colouration over the rest of the plumage rendering it well camouflaged in open habitats. Immature birds resemble the female. The Eastern subspecies (O. t. dybowskii) is more extensively grey in colour in both sexes, with more extensive barring on the back. The great bustard has long legs, a long neck and a heavy, barrel-chested body. It is fairly typical of the family in its overall shape and habitat preferences.
Habitat and Distribution
This bird's habitat is grassland or steppe defined by open, flat or somewhat rolling landscapes. It can be found on undisturbed cultivation and seems to prefer areas with wild or cultivated crops such as cereals, vineyards and fodder plants. However, during the breeding season, they actively avoid areas with regular human activity and can be distributed by agricultural practices. Great bustards are often attracted to areas with considerable insect activity.
This species is omnivorous, taking different foods in differing seasons. In northwestern Spain in August, 48.4% of the diet of adult birds was comprised by green plant material, 40.9% was invertebrates and 10.6% was seeds.
One to three olive or tan coloured, glossy eggs (two eggs being the average) are laid by the female in May or June. The nests, which are shallow scrapes made by the female on dry, soft slopes and plains, are usually situated close to the prior lek location. Nests are situated in sparse clusters.
Calls and Songs
Both sexes are usually silent but can engage in deep grunts when alarmed or angered. The displaying adult male may produce some booming, grunting and raucous noises. The female may utter some guttural calls at the nest and brooded young make a soft, trilling call in communication with their mothers.