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The
Ostrich,
Struthio camelus, is a large flightless bird
native to Africa. It is the only living species of its family, Struthionidae and its genus,
Struthio.
Ostriches share the order Struthioniformes with the kiwis, Emus, and
other ratites. It is distinctive in its appearance, with a long neck and
legs and the ability to run at maximum speeds of about 45 miles per
hour (72 km/h), the top land speed of any bird). The Ostrich is the
largest living species of bird and lays the largest egg of any living
bird (extinct elephant birds of Madagascar and giant moa of New Zealand
laid larger eggs).
The diet of the Ostrich mainly consists of plant matter, though it also
eats insects. It lives in nomadic groups which contain between five and
fifty birds. When threatened, the Ostrich will either hide itself by
lying flat against the ground, or will run away. If cornered, it can
attack 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.
Ostriches
usually weigh from 63 to 130 kilograms (140–290 lb), with exceptional
male Ostriches weighing up to 155 kilograms (340 lb). The feathers of
adult males are mostly black, with white primaries and a white tail.
However, the tail of one subspecies is buff. Females and young males are
greyish-brown and white. The head and neck of both male and female
Ostriches is nearly bare, with a thin layer of down.. The skin of the
females neck and thighs is pinkish gray, while the male's is blue or
gray dependent on subspecies.
The long neck and legs keeps their head 1.8 to 2.75 metres (6 to 9 ft)
above the ground, and their eyes are said to be the largest of any land
vertebrate – 50 millimetres (2.0 in) in diameter; they can therefore
perceive predators at a great distance. The eyes are shaded from sun
light falling from above.
Their
skin is variably coloured depending on the sub-species. The male tarsus
has red horn plates, while the female's are black. The strong legs of
the Ostrich, like those of other birds, are scaled and unfeathered. The
bird has just two toes on each foot (most birds have four), with the
nail on the larger, inner toe resembling a hoof. The outer toe lacks a
nail. The reduced number of toes is an adaptation that appears to aid in
running. The wings reach a span of about 2 metres (6 ft 7 in) and are
used in mating displays and to shade chicks. The feathers lack the tiny
hooks that lock together the smooth external feathers of flying birds,
and so are soft and fluffy and serve as insulation. They have 50-60 tail
feathers, and their wings have 16 primary, four alular and 20-23
secondary feathers. 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. They have three stomachs, and the caecum is 28
inches (71 cm) long. Unlike all other living birds, the Ostrich
secretes urine separately from feces. They also have unique pubic bones
that are fused to hold their gut. Unlike most birds the males have a
copulatory organ, which is retractable and 8 inches (20 cm) long. Their
palate is different than other ratites, in that the sphenoid and palatal
bones are unconnected.
At
sexual maturity (two to four years), male Ostriches can be from 1.8 to
2.8 metres (5 ft 11 in to 9 ft 2 in) in height, while female Ostriches
range from 1.7 to 2 metres (5 ft 7 in to 6 ft 7 in). During the first
year of life, chicks grow about 25 centimetres (10 in) per month. At one
year of age, Ostriches weigh around 45 kilograms (100 lb).
Source: wikipedia.org
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