The flightless Ostrich (Struthio camelus) is the only species in the genus Struthio and in the family Struthionidae. The Ostrich is the tallest and heaviest living bird. Males are 2.1 to 2.75 m tall and weigh 100 to 130 (or even 150) kg; females are around 1.75 to 1.9 m tall and weigh 90 to 110 kg. The eyes are the largest of any terrestrial vertebrate, with a diameter of 5 cm. Its long, stout legs allow an Ostrich to cover a lot of ground quickly and can also serve as powerful weapons; each foot has a 10 cm sturdy flattened claw on the thick inner toe (uniquely among living birds, there are only two toes on each foot). The Ostrich is the fastest runner among birds. It can maintain a speed of 50 km/h for around half an hour and can sprint to 70 km/h with strides of 3.5 m, using its wings for balance at high speeds.
The male Ostrich is mostly pitch black, but the wings and tail are a sharply contrasting pure white; females are notably drabber. The Ostrich is one of the relatively few bird species that has a penis, which the male displays prominently during courtship.
Ostriches are found across much of the Sahel and eastern and southern Africa in a range of open habitats, from savanna to desert (in southern Australia there are some small populations of feral Ostriches from abandoned Ostrich farming operations). Ostriches do not require drinking water since they obtain sufficient water mainly from succulent plants. On hot days, they can allow their body temperature to rise to 42 C, reducing water loss through transpiration.
Outside the breeding season, Ostriches tend to live in small groups (although hundreds of Ostriches may congregate around water sources in the dry season). During the breeding season, birds form pairs or small harems. Males are territorial and engage in conspicuous courtship rituals. Multiple females may lay eggs in a single nest; a single nest may contain dozens of eggs, although only around two dozen can be incubated. Both the male and female incubate, with the more conspicuous male taking the night shift. Each egg weighs around 1.5 kg--enormous in absolute terms, but only around 1.5% of the adult female's weight. Eggs hatch together after around six weeks.
The idea that an Ostrich will bury its head in the sand in the face of danger is a myth, although when it feels trapped an Ostrich may sit down motionless with head and neck stretched on the ground in front of it in an apparent attempt to remain inconspicuous.
Ostriches produce many vocal and non-vocal sounds. They are omnivorous, but generally feed largely on plant material. The 14 m intestines allow them to eat many foods rejected by many other animals not equipped to extract enough of value from less desirable food items.
Ostriches have long been exploited by humans for their feathers, eggs, meat, and skin. At one time the Ostrich was common in most of Africa and southwestern Asia. Today, the range is considerably reduced and the subspecies that used to occur from the Syrian desert to the Arabian Peninsula was virtually extinct by 1941, having declined rapidly after World War I, with the last known record being a drowning individual in Jordan in 1966. There have been some efforts to reintroduce Ostriches to the Middle East.
(Folch 1992 and references therein)
Ostriches are large flightless birds. They are the heaviest living birds, and lay the largest eggs of any living land animal. With the ability to run at 70 km/h (43.5 mph), they are the fastest birds on land. They are farmed worldwide, with significant industries in the Philippines and Namibia. Ostrich leather is a lucrative commodity, and the large feathers are used as plumes for the decoration of ceremonial headgear. Ostrich eggs have been used by humans for millennia.
Ostriches are of the genus Struthio in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, cassowaries and kiwis. There are two living species of ostrich: the common ostrich, native to large areas of sub-Saharan Africa, and the Somali ostrich, native to the Horn of Africa.[2] The common ostrich used to be native to the Arabian Peninsula, and ostriches were present across Asia as far east as China and Mongolia during the Late Pleistocene and possibly into the Holocene.
The genus Struthio was first described by Carl Linnaeus in 1758. The genus was used by Linnaeus and other early taxonomists to include the emu, rhea, and cassowary, until they each were placed in their own genera.[1] The Somali ostrich (Struthio molybdophanes) has recently become recognized as a separate species by most authorities, while others are still reviewing the evidence.[3][4]
Struthionidae is a member of the Struthioniformes, a group of paleognath birds which first appeared during the Early Eocene, and includes a variety of flightless forms which were present across the Northern Hemisphere (Europe, Asia and North America) during the Eocene epoch. The closest relatives of Struthionidae within the Struthioniformes are the Ergilornithidae, known from the late Eocene to early Pliocene of Asia. It is therefore most likely that Struthionidae originated in Asia.[5]
The earliest fossils of the genus Struthio are from the early Miocene ~21 million years ago of Namibia in Africa, so it is proposed that genus is of African origin. By the middle to late Miocene (5–13 mya) they had spread to and become widespread across Eurasia.[6] While the relationship of the African fossil species is comparatively straightforward, many Asian species of ostrich have been described from fragmentary remains, and their interrelationships and how they relate to the African ostriches are confusing. In India, Mongolia and China, ostriches are known to have become extinct only around, or even after, the end of the last ice age; images of ostriches have been found prehistoric Chinese pottery and petroglyphs.[7][8][9][10]
Struthio camelus egg – MHNT
Size comparison (with a chicken egg and a US dollar bill)
Ostrich with eggs
Today, ostriches are only found natively in the wild in Africa, where they occur in a range of open arid and semi-arid habitats such as savannas and the Sahel, both north and south of the equatorial forest zone.[11] The Somali ostrich occurs in the Horn of Africa, having evolved isolated from the common ostrich by the geographic barrier of the East African Rift. In some areas, the common ostrich's Masai subspecies occurs alongside the Somali ostrich, but they are kept from interbreeding by behavioral and ecological differences.[12] The Arabian ostriches in Asia Minor and Arabia were hunted to extinction by the middle of the 20th century, and in Israel attempts to introduce North African ostriches to fill their ecological role have failed.[13] Escaped common ostriches in Australia have established feral populations.[14][15][16]
In 2008, S. linxiaensis was transferred to the genus Orientornis.[17] Three additional species, S. pannonicus, S. dmanisensis, and S. transcaucasicus, were transferred to the genus Pachystruthio in 2019.[18] Several additional fossil forms are ichnotaxa (that is, classified according to the organism's trace fossils such as footprints rather than its body) and their association with those described from distinctive bones is contentious and in need of revision pending more good material.[19]
The species are:
Ostriches are large flightless birds. They are the heaviest living birds, and lay the largest eggs of any living land animal. With the ability to run at 70 km/h (43.5 mph), they are the fastest birds on land. They are farmed worldwide, with significant industries in the Philippines and Namibia. Ostrich leather is a lucrative commodity, and the large feathers are used as plumes for the decoration of ceremonial headgear. Ostrich eggs have been used by humans for millennia.
Ostriches are of the genus Struthio in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, cassowaries and kiwis. There are two living species of ostrich: the common ostrich, native to large areas of sub-Saharan Africa, and the Somali ostrich, native to the Horn of Africa. The common ostrich used to be native to the Arabian Peninsula, and ostriches were present across Asia as far east as China and Mongolia during the Late Pleistocene and possibly into the Holocene.
