health and technology

Ostrich

A large flightless bird native to Africa (and formerly the Middle East). It is the only living species of its family, Struthionidae, and its genus, Struthio. Ostriches share the order Struthioniformes with emus, kiwis, and other ratites. It is distinctive in its appearance, with a long neck and legs and the ability to run at speeds of about 65 km/h (40 mph), the top land speed of any bird. The Ostrich is the largest living species of bird and lays the largest egg of any bird species.
The diet of the Ostrich mainly consists of seeds and other plant matter, though it eats insects. It lives in nomadic groups which contain between five and 50 birds. When threatened, the Ostrich will either hide itself by lying flat against the ground, or will run away. If cornered, it can cause injury and death with a kick from its powerful legs. Mating patterns differ by geographical region, but territorial males fight for a harem of two to seven females.
The Ostrich is farmed around the world, particularly for its feathers, which are decorative and are also used for feather dusters. Its skin is used for leather and its meat marketed commercially.

Scientific classification

Kingdom: Animalia Phylum: Chordata Class: Aves Order: Struthioniformes Family: Struthionidae Vigors, 1825 Genus: Struthio Linnaeus, 1758 Species: S. camelus

Binomial name

Struthio camelus Linnaeus, 1758

Subspecies

Five subspecies are recognized:

• S. c. australis

• S. c. camelus

• S. c. massaicus
• In East Africa, sometimes called the Masai Ostrich. It has some small feathers on its head, and its neck and thighs are bright orange. During the mating season, the male's neck and thighs become brighter. Their range is essentially limited to most of Kenya and Tanzania and parts of Southern Somalia.
• S. c. syriacus
• In the Middle East, sometimes called the Arabian Ostrich or Middle Eastern Ostrich, was a subspecies formerly very common in the Arabian Peninsula, Syria, and Iraq; it became extinct around 1966.
• S. c. molybdophanes
• In Somalia, Ethiopia, and northern Kenya, is called the Somali Ostrich. The neck and thighs are grey-blue, and during the mating season, the male's neck and thighs become bright blue. The females are more brown than those of other subspecies. It generally lives in pairs or alone, rather than in flocks. Its range overlaps with S. c. massaicus in northeastern Kenya.

• Struthio coppensi (Early Miocene of Elizabethfeld, Namibia)
• Struthio linxiaensis (Liushu Late Miocene of Yangwapuzijifang, China)
• Struthio orlovi (Late Miocene of Moldavia)
• Struthio karingarabensis (Late Miocene - Early Pliocene of SW and CE Africa) - oospecies(?)
• Struthio kakesiensis (Laetolil Early Pliocene of Laetoli, Tanzania) - oospecies
• Struthio wimani (Early Pliocene of China and Mongolia)
• Struthio daberasensis (Early - Middle Pliocene of Namibia) - oospecies
• Struthio brachydactylus (Pliocene of Ukraine)
• Struthio chersonensis (Pliocene of SE Europe to WC Asia) - oospecies
• Asian Ostrich, Struthio asiaticus (Early Pliocene - Late Pleistocene of Central Asia to China)
• Struthio dmanisensis (Late Pliocene/Early Pleistocene of Dmanisi, Georgia)
• Struthio oldawayi (Early Pleistocene of Tanzania) - probably subspecies of S. camelus
• Struthio anderssoni - oospecies(?)

Description

Ostriches usually weigh from 93 to 130 kg (200 to 285 lb), although some male ostriches have been recorded with weights of up to 155 kg (340 lb). The feathers of adult males are mostly black, with white at the ends of the wings and in the tail. Females and young males are greyish-brown and white. The head and neck of both male and female Ostriches is nearly bare, but has a thin layer of down.
The strong legs of the Ostrich lack feathers. The bird has just two toes on each foot (most birds have four), with the nail of the larger, inner one resembling a hoof. The outer toe lacks a nail. This is an adaptation unique to Ostriches that appears to aid in running. The wings are not used for flight, but are still large, with a wingspan of around two metres (over six feet), despite the absence of long flight feathers. The wings are used in mating displays, and they can also provide shade for chicks. The feathers, which are soft and fluffy, serve as insulation, and are quite different from the flat smooth outer feathers of flying birds (the feather barbs lack the tiny hooks which lock them together in other birds). The ostrich's sternum is flat, lacking the keel to which wing muscles attach in flying birds. The beak is flat and broad, with a rounded tip. Like all ratites, the Ostrich has no crop, and it also lacks a gallbladder.
At sexual maturity (two to four years old), male Ostriches can be between 1.8 and 2.7 m (6 and 9 ft) in height, while female Ostriches range from 1.7 to 2 m (5.5 to 6.5 ft). During the first year of life, chicks grow about 25 cm (10 in) per month. At one year of age, ostriches weigh around 45 kg (100 lb). An Ostrich can live up to 75 years.
Ostriches are native to savannas and the Sahel of Africa, both north and south of the equatorial forest zone. The Arabian Ostriches in the Near and Middle East were hunted to extinction by the middle of the 20th century.

Behaviour

With their acute eyesight and hearing, they can sense predators such as lions from far away. When being pursued by a predator, Ostriches have been known to reach speeds in excess of 65 km per hour (40 miles per hour), and can maintain a steady speed of 50 km/h (30  mph), which makes the ostrich the world's fastest two-legged animal.
Ostriches are known to eat almost anything ( dietary indiscretion), particularly in captivity where opportunity is increased.
Ostriches can tolerate a wide range of temperatures. In much of its habitat, temperature differences of 40°C between night- and daytime can be encountered. Their temperature control mechanism is more complex than in other birds and mammals, utilizing the naked skin of the upper legs and flanks which can be covered by the wing feathers or bared according to whether the bird wants to retain or lose body heat.
When lying down and hiding from predators, the birds lay their head and neck flat on the ground, making them appear as a mound of earth from a distance. This even works for the males, as they hold their wings and tail low so that the heat haze of the hot, dry air that often occurs in their habitat aids in making them appear as a nondescript dark lump. When threatened, Ostriches run away, but they can cause serious injury and death with kicks from their powerful legs. Their legs can only kick forward.

Reproduction

Ostriches become sexually mature when they are 2 to 4 years old; females mature about six months earlier than males. The species is iteroparous, with the mating season beginning in March or April and ending sometime before September. The mating process differs in different geographical regions. Territorial males will typically use hisses and other sounds to fight for a harem of two to seven females (which are called hens). The winner of these fights will breed with all the females in an area, but will only form a pair bond with the dominant female. The female crouches on the ground and is mounted from behind by the male.
Ostriches are oviparous. The females will lay their fertilized eggs in a single communal nest, a simple pit, 30 to 60 cm (12-24 in) deep, scraped in the ground by the male. Ostrich eggs are the largest of all eggs (and by extension, the yolk is the largest single cell), though they are actually the smallest eggs relative to the size of the bird. The nest may contain 15 to 60 eggs, which are, on average, 15 cm (6 in) long, 13 cm (5 in) wide, and weigh 1.4 kg (3 lb). They are glossy and cream in colour, with thick shells marked by small pits. The eggs are incubated by the females by day and by the male by night. This uses the coloration of the two sexes to escape detection of the nest, as the drab female blends in with the sand, while the black male is nearly undetectable in the night. The incubation period is 35 to 45 days. Typically, the male will defend the hatchlings, and teach them how and on what to feed.
The life span of an Ostrich is from 30 to 70 years, with 50 being typical.
Ostriches reared entirely by humans may not learn to direct their courtship behaviour at other ostriches, but instead may do so at their human keepers.

Ostrich feather dusters

The original South African ostrich feather dusters were invented in Johannesburg, South Africa by missionary, broom factory manager, Harry S. Beckner in 1903.
The Ostrich feather is durable, soft and flexible, which accounts for the success of the Ostrich feather duster over the last 100 years. Because the feather does not zipper together it is prone to developing a static charge which actually attracts and holds dust which can then be shaken out or washed off. Because of its similar makeup to human hair, care of the ostrich feather requires only an occasional shampoo and towel or air dry. The farming of Ostriches for their feathers does not harm the bird. During molting season the birds are gathered in a pen, burlap sacks are placed over their heads so they will remain calm and trained pickers pluck the loose molting feathers from the birds. The birds are then released unharmed back onto the farm.
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