They are the heaviest and largest living birds, with adult common ostriches weighing anywhere between 63.5 and 145 kilograms and laying the largesteggs of any living land animal.[3] With the ability to run at 70 km/h (43.5 mph),[4] they are the fastest birds on land. They are farmed worldwide, with significant industriesin the Philippines andin Namibia.South Africa produces about 70% of global ostrich products,[5] with the industry largely centered around the town ofOudtshoorn.Ostrich leather is a lucrative commodity, and the large feathers are used asplumes for the decoration of ceremonial headgear.Ostrich eggs andmeat have been used by humans for millennia.Ostrich oil is another product that is made using ostrich fat.
The common ostrich was historically native to theArabian Peninsula, and ostriches were present across Asia as far east as China and Mongolia during theLate Pleistocene and possibly into theHolocene.
Mating dance of the Ostrich.
Taxonomic history
The genusStruthio was first described byCarl Linnaeus in 1758. The genus was used by Linnaeus and other early taxonomists to include theemu,rhea, andcassowary, 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.[6][7]
Evolution
Struthionidae is a member of theStruthioniformes, a group ofpaleognath birds which first appeared during the EarlyEocene, 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 theErgilornithidae, known from the late Eocene to earlyPliocene of Asia. It is therefore most likely that Struthionidae originated in Asia.[8]
The earliest fossils of the genusStruthio are from the earlyMiocene ~21 million years ago of Namibia in Africa, so it is proposed that genus is of African origin. By the middle to lateMiocene (5–13 mya) they had spread to and become widespread across Eurasia.[9] 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 andChina, ostriches are known to have become extinct only around, or even after, the end of thelast ice age; images of ostriches have been found prehistoric Chinese pottery andpetroglyphs.[10][11][12][13]
Size comparison (with a chicken egg and a US dollar bill)
Ostrich with eggs
Distribution and habitat
Today, ostriches are only found natively in the wild inAfrica, where they occur in a range of open arid and semi-arid habitats such assavannas and theSahel, both north and south of the equatorial forest zone.[14] TheSomali ostrich occurs in theHorn of Africa, having evolved isolated from the common ostrich by the geographic barrier of theEast African Rift. In some areas, the common ostrich'sMasai subspecies occurs alongside the Somali ostrich, but they are kept from interbreeding by behavioral and ecological differences.[15] TheArabian ostriches inAsia Minor andArabia were hunted to extinction by the middle of the 20th century, and inIsrael attempts to introduceNorth African ostriches to fill their ecological role have failed.[16] Escaped common ostriches in Australia have establishedferal populations.[17][18][19]
Species
A male Somali ostrich in aKenyansavanna, showing its blueish neck
In 2008,S. linxiaensis was transferred to the genusOrientornis.[20] Three additional species,S. pannonicus,S. dmanisensis, andS. transcaucasicus, were transferred to the genusPachystruthio in 2019.[21] Several additional fossil forms areichnotaxa (that is, classified according to the organism'strace 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.[22]
^abJanz, Lisa; et al. (2009). "Dating North Asian surface assemblages with ostrich eggshell: Implications for palaeoecology and extirpation".Journal of Archaeological Science.36 (9):1982–1989.Bibcode:2009JArSc..36.1982J.doi:10.1016/j.jas.2009.05.012.
^abAndersson, Johan Gunnar (1923).On the occurrence of fossil remains of Struthionidae in China. In: Essays on the cenozoic of northern China. Memoirs of the Geological Survey of China (Peking), Series A, No. 3, pp. 53–77. Peking, China: Geological Survey of China.
^Wang, S. (2008). "Rediscussion in the taxonomic assignment ofStruthio linxiaensis Hou, et al., 2005".Acta Paleontologica Sinica.47:362–368.
^Zelenkov, N. V.; Lavrov, A. V.; Startsev, D. B.; Vislobokova, I. A.; Lopatin, A. V. (2019). "A giant early Pleistocene bird from eastern Europe: unexpected component of terrestrial faunas at the time of early Homo arrival".Journal of Vertebrate Paleontology.39 (2): e1605521.Bibcode:2019JVPal..39E5521Z.doi:10.1080/02724634.2019.1605521.S2CID198384367.
^Andersson, Johan Gunnar (1943). "Research into the prehistory of the Chinese".Bulletin of the Museum of Far Eastern Antiquities.15:1–300.
General references
Andersson, Johan Gunnar (1943). "Researches into the prehistory of the Chinese".Bulletin of the Museum of Far Eastern Antiquities.15:1–300, plus 200 plates.
Brands, Sheila (14 Aug 2008)."Taxon: Genus Struthio".Project: The Taxonomicon. Retrieved12 Jun 2012.
Davies, S. J. J. F. (2003). "Ostriches". In Hutchins, Michael (ed.).Birds I Tinamous and Ratites to Hoatzins.Grzimek's Animal Life Encyclopedia. Vol. 8 (2nd ed.). Farmington Hills, MI: Gale Group. p. 99.ISBN978-0-7876-5784-0.
Janz, Lisa; et al. (2009). "Dating North Asian surface assemblages with ostrich eggshell: Implications for palaeoecology and extirpation".Journal of Archaeological Science.36 (9):1982–1989.Bibcode:2009JArSc..36.1982J.doi:10.1016/j.jas.2009.05.012.
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