Facts about Emu
The Emu is the largest bird native to Australia. It is the only extant member of the genus Dromaius. It is the second-largest extant bird in the world by height, after its ratite relative, the ostrich. During the breeding season, male Emus experience hormonal changes, including an increase in luteinizing hormone and testosterone levels, and their testicles double in size. Interestingly, the male becomes broody after his mate starts laying, and begins to incubate the eggs before the laying period is complete. From this time on, he does not eat, drink or defecate, and stands only to turn the eggs, which he does about 10 times a day. Over eight weeks of incubation, he will lose a third of his weight and will survive only on stored body-fat and on any morning dew that he can reach from the nest. The Emu was first described under the name of the New Holland Cassowary in Arthur Phillip's 'Voyage to Botany Bay', published in 1789. It has featured on numerous Australian postage stamps, including a pre-federation New South Wales 100th Anniversary issue from 1888, which featured a 2 pence blue Emu stamp, a 36 cent stamp released in 1986, and a $1.35 stamp released in 1994. They are opportunistically nomadic and may travel long distances to find food. It appears as a shield bearer on the Coat of Arms of Australia with the Red Kangaroo and as a part of the Arms also appears on the Australian 50 cent coin. The first verified occurrence of genetically identical avian twins was demonstrated in the Emu. Their eggs are on average 134 by 89 millimetres (5.3 in × 3.5 in) and weigh between 700 and 900 grams (1.5 and 2.0 lb), which is roughly 'equivalent to 10–12 chicken eggs' in volume and weight. Emus are also able to swim when necessary. The Emu has a prominent place in Australian Aboriginal mythology, including a creation myth of the Yuwaalaraay and other groups in NSW who say that the sun was made by throwing an Emu's egg into the sky; the bird features in numerous aetiological stories told across a number of Aboriginal groups. As far as mating is concerned, the pair mates every day or two, and every second or third day the female lays one of an average of 11 (and as many as 20) very large, thick-shelled, dark-green eggs. The number of eggs vary with rainfall. They reach up to 2 metres (6.6 ft) in height. They have small vestigial wings and a long neck and legs. A unique feature of the Emu feather is its double rachis emerging from a single shaft. The scientific name of this bird is Latin for "fast-footed New Hollander". Emus can travel great distances at a fast, economical trot and, if necessary, can sprint at 50 km/h (31 mph) for some distance at a time. The shafts and the tips of their feathers are black. Solar radiation is absorbed by the tips, and the loose-packed inner plumage insulates the skin. Their naked skin on the neck is bluish-black. On very hot days, Emus pant to maintain their body temperature, their lungs work as evaporative coolers and, unlike some other species, the resulting low levels of carbon dioxide in the blood do not appear to cause alkalosis. Their calls consist of loud booming, drumming and grunting sounds that can be heard up to two kilometers away. The booming sound is created in an inflatable neck sac that is 30 cm (12 in) long and thin-walled. Emus have only three toes in a tridactyl arrangement; this adaptation for running is seen in other bird species, such as bustards and quails. While the Ostrich has only two toes. In the wild, Emus live between 10 to 20 years; captive birds can live longer than those in the wild. Emus weigh between 18 and 48 kilograms (40 and 110 lb). The etymology of the common name Emu is uncertain, but is thought to have come from an Arabic word for large bird that was later used by Portuguese explorers to describe the related Cassowary in New Guinea. They have a soft bill, adapted for grazing. Newly hatched Emu chicks are active and can leave the nest within a few days. They stand about 12 centimetres (5 in) tall, weigh .5 kg (18 oz) and have distinctive brown and cream stripes for camouflage, which fade after three months or so. The Emu is popularly but unofficially considered as a faunal emblem—the national bird of Australia. Emus also require pebbles and stones to assist in the digestion of the plant material. Individual stones may weigh 45 g (1.6 oz) and they may have as much as 745 g (1.64 lb) in their gizzard at one time. Emu eyes are golden brown to black. Emus are observed eating charcoal, however scientists still have not ascertained why. Emus form breeding pairs during the summer months of December and January, and may remain together for about five months. They eat a variety of native and introduced plant species; the type of plants eaten depends on seasonal availability. They also eat insects, including grasshoppers and crickets, lady birds, soldier and saltbush caterpillars, Bogong and cotton-boll moth larvae and ants. Emu chicks have longitudinal stripes that help to camouflage them. Their mating occurs in the cooler months of May and June. Incubation of their eggs takes 56 days. The male stays with the growing chicks for up to 18 months, defending them and teaching them how to find food. The "Kurdaitcha man" of Central Australia is said to wear sandals made of emu feathers to mask his footprints. |
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