Seen from afar, the Australian emu looks like a little ostrich. In addition to size, the two runner birds exhibit many differences and are not, moreover, part of the same family. Close-up on the emu, second biggest bird in the world.
Australian Emu Identity Card
The Australian emu (Dromaius novaehollandiae) is a species of runner bird belonging to the order Casuariiformes and to the family of dromaiids of which he is the only representative. Like other species of runner birds called ratites (ostrich, cassowary), it is unable to fly because it lacks wishbone in the sternum: this bone of the chest, on which the powerful pectoral and supracoracoid muscles are inserted, is indeed essential for flight. The second largest bird in the world, the Australian emu measures between 1.50 and 1.90 m and weighs 30 to 45 kg (the female being more massive than the male).
Description of the Australian emu
The Australian emu has soft plumage and bushy, dark brown to gray-brown. Its thick feathers divide very clearly in the middle of the back to fall on each side of the body. The head, chin, throat and cheeks are adorned with black feathers. The upper neck has a bare skin, pale blue in color. The bill is gray with reddish eyes and small wings atrophied hide under the plumage. They can move away from the body during hot weather and thus generate a drop in temperature. The massive body is carried by two powerful gray legs whose feet end in three powerful toes.
Differences between emus and ostriches
Below are the main distinguishing features of the ostrich:
- It belongs to the order Struthioniformes and to the family of Struthionidae;
- She has plumage black with white wings and tail;
- Its neck and head are devoid of feathers, only covered with down;
- Females are significantly more small than males (the male can measure from 2 to 3 m and the female from 1.75 to 2 m);
- Its paws have only two fingers at each foot.
Australian emu habitat
As its name suggests, the emu lives in Australia outside the desert areas and certain parts of the southwest of the continent. The flightless animal prefers big spaces where he can undertake long races: open to semi-open environments, open forests, arid plains, savannas low trees. It breeds in grassy areas, heather moors or woods and scrub. Emus are sedentary but nomads depending on water and food resources. Seasonal movements of more than 500 km are observed in Western Australia where birds follow the rains going from north to south.
Australian emu diet
Omnivorous, the Australian emu consumes a wide variety of seeds trees and shrubs, fruits, young shoots, flowers and tender roots. It also captures large insects (caterpillars, grasshoppers, beetles) and some small vertebrates such as rodents or lizards. The Australian emu absorbs pebbles to help her stomach digest properly. He also practices coprophagia (eats his feces) to avoid dehydration in dry areas where food is scarce. When food is plentiful, the ratite forms fat stores which will serve him in times of famine. When it is near a water point, the animal has its habits: it drinks two to thrice per day in summer (mid-morning, mid-day and late afternoon).
Australian emu behavior
Developing little social relations with its congeners, the Australian emu lives in solitary or as a couple. Outside the breeding season, it shows itself rather gregarious, forming small groups to move around when food sources are plentiful. Its high legs and powerful fingers allow it to walk long and reach 48 km / hour in case of danger. The species is found in a roost in each feeding area: it usually sleeps on the ground, but it can take refuge in vegetation during a cold winter. Its plumage cryptic helps it blend into the background of the dry herbs.
Reproduction of the Australian emu
In this species, reproduction is based on polyandry : females mate with several males who perform all nesting duties. Thus, the male digs a cup of 1 meter in diameter on the ground, near a tree or a bush. It is in this nest lined with grasses, stems, twigs and straw that his partner will lay eggs. 9 to 11 large eggs dark green each weighing between 450 and 650 grams. The male incubates for about 2 months during which he fasts and does not drink. Drawing on his fat reserves, the progenitor plunges into a kind of lethargy in order to reduce its energetic expenses. He does, however, turn the eggs every day and aggressively chase everything intruder, including the female to avoid re-spawning. Note that in the ostrich, it is the couple who takes care of the brooding: the female during the day and the male at night.
Nidifuges, chicks are able to walk within 24 hours of birth and learn to run and swim very quickly. The male takes care of them and can also agree to watch over small emus lost other broods provided they are younger than its offspring. The father keeps watch for another 5 to 7 months then he starts looking for a new partner for the next mating season. Juveniles will be sexually mature around 2 or 3 years old, the age at which they in turn can reproduce.
Threats to the Australian emu
Raptors, foxes and wild dogs (dingoes) are the main predators of the Australian emu. For the Aborigines, these land birds were a major source of meat while their fat was used in traditional medicine as an ointment. Theemu oil was also mixed with ocher to make traditional ceremonial paints. Upon arrival of European settlers in the XVIIIe century in Australia and the neighboring islands, intensive hunting has been practiced, to the point of wiping out the subspecies once present in Tasmania.
Conservation status of the Australian emu
At the beginning of the XXe century, expansion of agriculture has resulted in conflicts between farmers and runner birds. In 1932, during an important period of drought, emus migrated to cultivated land rich in water and food. Entering the fields, the ratites severely damaged crops and triggered the “emu war”During which bounties were offered to kill animals. However, faced with the failure of the destruction campaigns, the cultivators finally opted for the construction of impassable fences. Today, Australian emus are bred for their meat and leather and are not considered a species threatened. The lifespan of the dromaiid is 10 in the wild and 20 years in captivity.