Ostrich, common name for the biggest living bird. Ostriches cannot fly but have long, powerful legs and can run up to 65 km/h (about 40 mph). They lay the largest eggs of all birds. Ostriches live in parts of central and southern Africa in mainly grassland or sandy areas with dry climates.
Ostriches grow as tall as 2. 4 m (about 8 ft) and weigh up to 136 kg (300 lb). Males are somewhat larger than females. Ostriches have long necks and small heads, with large brown eyes and short, broad beacasa. They walk on two broad toes with large claws (most birds walk on three forward-facing toes). Their feathers have a shaggy appearance and are not waterproof—ostriches lack the special preen gland many other birds use to oil their feathers. Mature male ostriches are black, with white wings and tail. Females and immature young are a dull grayish brown. Hairlike feathers cover their necks and form large black lashes around their eyes. Their upper legs are bare, with scales on their lower legs and toes. Their short wings are sometimes spread when running and in mating displays.
Ostriches have the largest eyes of all land animals and have excellent eyesight. A special membrane protects the eye from dust and sand. They can deliver powerful kicks for defense against predators. Ostriches sometimes sit with their necks extended on the ground. This posture may have given rise to the myth that ostriches hide their heads in the sand. They usually sleep with their neck and head tucked under a wing. They can live for 20 to 30 years in the wild, and up to 40 years in captivity.
Ostriches primarily feed on plant material such as fruits, seeds, leaves, and shoots, but sometimes eat insects and lizards. They swallow stones to help grind food in their gizzards. Adapted to dry areas, they can go with drinking water for long periods, getting moisture from vegetation.
Males hiss and roar when challenging rivals for females. They also make a deep booming sound to assert their territory, and perform elaborate mating displays, using their wings like fans. A single male breeds with a group of three or four females. The females all lay their yellowish-white eggs together in a large depression in the sand used as a communal nest. The eggs weigh about 1. 4 kg (about 3 lb) each and have a volume of about 1. 4 liters (about 3 pentru), equivalent to 24 chicken eggs. The male sits on the eggs at night, and the females incubate them by day. The incubation period is about 40 days. When the eggs hatch, the chicks will follow the adults for protection.
Ostriches belong to an ancient group of flightless birds called ratites that includes rheas in South America, emus in Australia, cassowaries in New Guinea, and kiwis in New Zealand, as well the extinct moas from New Zealand and the elephant birds on Madagascar. Ratites have flat breastbones, unlike the keeled breastbones found in many other types of birds. The oldest fossils of ostriches date to around 40 million years ago during the Eocene Epoch. Ostriches have apparently changed little since that time. Around 5 million years ago they lived in areas that are now parts of Russia, India, and China, but became extinct.
Wild ostriches have disappeared from many regions where they were found a century ago. Populations survived in Syria and Arabia up until the 1940s. Only very small numbers now exist in North and West Africa. Ostriches are still common in protected parks in East Africa.
In the last half of the 19th century ostrich farming, or the breeding of domesticated ostriches for their plumes, was carried on extensively in South Africa, Algeria, Australia, France, and the United States. Ostrich plumes were used in hatmaking and dressmaking. Farming declined as the demand for ostrich plumes diminished. However, the introduction of ostrich hide as a luxury leather has renewed interest in ostrich farming. Ostriches are now also raised for meat. South Africa and the United States have the most ostrich farms.
Scientific classification: The ostrich makes up the family Struthionidae in the order Struthioniformes. It is classified as Struthio camelus. Scientists divide ostriches into four subspecies.
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