The emu (Dromaius novaehollandiae) is the second-largest living bird by height, after its ratite relative, the ostrich. It is endemic to Australia where it is the largest native bird. Emus are soft-feathered, brown, flightless birds with long necks and legs, and can reach up to 1.9 m (6.2 ft) in height. Emus can travel great distances, and when necessary can sprint at 50 km/h (31 mph). The female is the most dominant and makes a distinct drumming sound. Females tend to be larger than males but the male is the only one who incubates the eggs for 54 days vs. ostriches 42 days. The eggs are dark green in colour.