The emu (Dromaius novaehollandiae) is the 2nd-largest living bird by height, after its ratite relative, the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus Dromaius. The emu's range covers most of mainland Australia, but the Tasmanian emu and King Island emu subspecies became extinct after the European settlement of Australia in 1788. The bird is sufficiently common for it to be rated as a least-concern species by the International Union for Conservation of Nature.
Emus are soft-feathered, brown, flightless birds with long necks and legs, and can reach up to 1.9 metres (6.2 ft) in height. Emus can travel great distances, and when necessary can sprint at 50 km/h (31 mph); they forage for a variety of plants and insects, but have been known to go for weeks without eating. They drink infrequently, but take in copious amounts of water when the opportunity arises.
Breeding takes place in May and June, and fighting among females for a mate is common. Females can mate several times and lay several clutches of eggs in 1 season. The male does the incubation; during this process he hardly eats or drinks and loses a significant amount of weight. The eggs hatch after around 8 weeks, and the young are nurtured by their fathers. They reach full size after around 6 months, but can remain as a family unit until the next breeding season. The emu is an important cultural icon of Australia, appearing on the coat of arms and various coins. The bird features prominently in Indigenous Australian mythology.
An adult male emu and several chicks appeared in "Dinosaurs". The adult male was also the mystery animal in "Running" and appeared again in "Who's in the Egg?" with several eggs that hatched. Another emu (possibly the same one from earlier), appeared in "Great Singers".