The emu (Dromaius novaehollandiae) is the second-tallest living bird in the world exceeded only by the ostrich. Emus are endemic to Australia where it is the largest native bird and is found throughout most of mainland Australia.
Emus are soft-feathered, brown, flightless birds with long necks and legs, and can reach up to 1.9 meters (6.2 ft) in height. Emus range in length from 139 to 164 cm (55 to 65 in). They are the fifth heaviest living bird in the world after the two species of ostrich and two larger species of cassowary. Adult emus weigh between 18 and 60 kg (40 and 132 lb), with an average of 31.5 and 37 kg (69 and 82 lb) in males and females, respectively.
Emus can travel great distances, and when necessary they can sprint at 50 km/h (31 mph). They flap their wings when running, perhaps as a means of stabilizing themselves when moving fast. Emus can run at speeds of 48 km/h (30 mph) due to their highly specialized pelvic limb musculature. When walking, the emu takes strides of about 100 cm (3.3 ft), but at full gallop, a stride can be as long as 275 cm (9 ft). Emus have good eyesight and hearing.
Emus primarily eat plants and insects but can go for weeks without eating. They drink infrequently but ingest large amounts of water when they do. Emus breed in May and June. The male incubates the eggs and hardly eats or drinks during that time, losing a significant amount of weight. The eggs hatch after about eight weeks, and the young are nurtured by their fathers. Emus reach full size after about six months. The emu plumage varies in color due to environmental factors. Feathers of emus in more arid areas with red soils have a rufous tint while birds residing in damp conditions are generally darker in hue. The juvenile plumage develops at about three months with the head and neck being especially dark. The adult plumage has developed by about fifteen months.