The emu is one of the most famous animals of Australia, a tall flightless bird, second in height to the ostrich. Adults have a covering of shaggy gray-brown feathers, apart from the head and neck, which are mostly naked and bluish-black. Their wings are greatly reduced in size, but they have long and powerful legs. There are three forward-facing toes on each foot, but no hind toe. Most emus are seen along roadsides, near a barrier like a fence, which suggests close association, but emus are not really social birds, except for the young, which remain with their father.
Australia is the only place emus are found and they inhabit almost the entire continent. There are fewer of them toward the center of the country and along the eastern coast. Historically they also lived on King and Kangaroo Islands, and on Tasmania, but on all three islands the species is now extinct. Emus inhabit a range of habitats including grassland, dry forest, wooded savannah, and semi-desert, but not the tropical forests in northeastern Australia.
An emu is generally a solitary bird, but will exhibit social behaviors when it is advantageous, such as sharing a nest and searching for food. Large groups will migrate together to the next source of food. During periods of incubation, emus are not nomadic. The home range of an individual measures 5 to 10 square km but is a dynamic area, as emus are always moving in search of food and water. This species is strictly diurnal. They wake very often during periods of sleep, due to threats from predators and the need to drink water. They exhibit playful curiosity with animals of their own and other species, particularly noted in captive environments. An example is biting or pecking another animal then running away, simply to get a response. They will swim when water is available, and are adept at this. These birds are able to communicate by means of an inflatable neck sack, creating sounds that carry 2 km. Their name is from their signature call, which sounds like "e-moo".
Emus are omnivorous and eat seeds, flowers, fruits and tender roots. During the summer they eat many insects, especially caterpillars, beetles and grasshoppers, and also small vertebrates.
Emus are polyandrous, which means that one female has multiple partners. A pair remains together for around five months, engaging in courtship, nest building and the laying of eggs. The female is dominant during pair formation but when incubation begins, she becomes aggressive to all other emus, her mate included. She wanders off and leaves all the incubation to him. The mating season is from December to January, starting with the pair doing a courtship dance. Then the male builds the nest of twigs, leaves and grass on the ground, in the shelter of vegetation. In April to May, 5 to 15 dark green eggs are laid. The male incubates them for about 8 weeks. Chicks are precocial and can walk within 24 hours. They are protected by their cryptic striped down. They are able to leave the nest 2 to 7 days after hatching, running and swimming very soon after that. The male looks after the young for 5 months, sometimes for as long as 18 months. They become mature by 2-3 years old.
Today the emu remains abundant and widespread. Following the arrival of settlers from Europe, emus were widely hunted for oil and meat, and their eggs were collected for food. As a result, they became extinct on several islands, including Tasmania.
According to the IUCN Red List, the total emu population size is estimated at 630,000 to 725,000 mature individuals. Currently this species is classified as Least Concern (LC) and its numbers today remain stable.
An emu disperses over a wide area the seeds from many low growing plants, due to their nomadic migratory habits. Some seeds feature a specialized coating that, once digested, increases the chance they will sprout.