Editing Common ostrich (section)

==Behaviour and ecology==
[[File:FlappingOstriches.jpg|thumb|Two birds "dancing"|alt=Pair "dancing"]]
[[File:Ostriches-Sleep-like-Platypuses-pone.0023203.s003.ogv|thumb|Sleeping, with [[Rapid eye movement sleep|REM sleep]] and [[slow-wave sleep]] phases<ref>{{Cite journal | last1 = Lesku | first1 = J. A. | last2 = Meyer | first2 = L. C. R. | last3 = Fuller | first3 = A. | last4 = Maloney | first4 = S. K. | last5 = Dell'Omo | first5 = G. | last6 = Vyssotski | first6 = A. L. | last7 = Rattenborg | first7 = N. C. | editor1-last = Balaban | editor1-first = Evan | title = Ostriches Sleep like Platypuses | doi = 10.1371/journal.pone.0023203 | journal = PLOS ONE | volume = 6 | issue = 8 | pages = e23203 | year = 2011 | pmid =  21887239| pmc =3160860 | bibcode = 2011PLoSO...623203L | doi-access = free }}</ref>]]

Common ostriches normally spend the winter months in pairs or alone. Only 16 percent of common ostrich sightings were of more than two birds.<ref name="Davies"/> During breeding season and sometimes during extreme rainless periods ostriches live in [[nomad]]ic groups of five to 100 birds (led by a top hen) that often travel together with other [[grazing]] animals, such as zebras or [[antelope]]s.<ref name="Donegan 2002"/> Ostriches are [[Diurnality|diurnal]], but may be active on moonlit nights. They are most active early and late in the day.<ref name="Davies"/> The male common ostrich territory is between {{cvt|2|and|20|km2}}.<ref name=Perrins2/>

[[File:Ostrich group nairobi.jpg|thumb|A large group of around 30 ostriches gathered in Nairobi National Park, Kenya.]]
With their acute eyesight and hearing, common ostriches can sense predators such as lions from far away. When being pursued by a predator, they have been known to reach speeds in excess of {{cvt|70|km/h}},<ref name="Davies"/> or possibly {{cvt|80|km/h}}<ref>Russell, Dale A. "Ostrich dinosaurs from the Late Cretaceous of western Canada."Canadian Journal of Earth Sciences 9.4 (1972): 375-402.</ref> and can maintain a steady speed of {{cvt|50|km/h}}, which makes the common ostrich the world's fastest two-legged animal.<ref name=DesertUSA/><ref name = "Stewart2006">{{cite web
 | last = Stewart | first = D. | title = A Bird Like No Other  | work = [[National Wildlife]]
 | publisher = [[National Wildlife Federation]] | date = 1 August 2006 | access-date = 25 April 2020
 | url = https://www.nwf.org/Magazines/National-Wildlife/2006/A-Bird-Like-No-Other
}}</ref> When lying down and hiding from predators, the birds lay their heads and necks flat on the ground, making them appear like a mound of earth from a distance, aided by the heat haze in their hot, dry habitat.<ref name=Werness/><ref name=Hiskey/>

{{anchor|kicks}}When threatened, common ostriches run away, but they can cause serious injury and death with kicks from their powerful legs.<ref name="Donegan 2002"/> Their legs can only kick forward.<ref name=Halcombe/> The kick from an ostrich can yield {{cvt|225|kgf}}.<ref>{{Cite thesis |last=Jelagat |first=Chemis |date=2009 |title=Studies on the possible causes of losses in Ostrich production in selected ostrich Farms in Kenya |url=http://erepository.uonbi.ac.ke/handle/11295/19110 |website=University of Nairobi|type=Thesis }}</ref>

===Feeding===
They mainly feed on seeds, shrubs, grass, fruit, and flowers;<ref name="Davies"/><ref name=Perrins2/> occasionally they also eat insects such as [[locust]]s, small reptiles such as lizards, and animal remains left by carnivorous predators.<ref name="Donegan 2002"/> Lacking teeth, they swallow pebbles that act as [[gastrolith]]s to grind food in the [[gizzard]]. When eating, they will fill their [[gullet]] with food, which is in turn passed down their esophagus in the form of a ball called a [[Bolus (digestion)|bolus]]. The bolus may be as much as {{cvt|210|mL}}. After passing through the neck (there is no [[Crop (anatomy)|crop]]) the food enters the [[gizzard]] and is worked on by the aforementioned pebbles. The gizzard can hold as much as {{cvt|1300|g}}, of which up to 45% may be sand and pebbles.<ref name=Perrins2/> Common ostriches can go without drinking for several days, using [[metabolic water]] and moisture in ingested plants,<ref name=Maclean/> but they enjoy liquid water and frequently take baths where it is available.<ref name="Donegan 2002"/> They can survive losing up to 25% of their body weight through [[dehydration]].<ref name=Perrins3/>

===Mating===
[[File:Common ostrich mating in ngorongoro.jpg|thumb|Mating in [[Ngorongoro Conservation Area]]]]
[[File:Ostrich with eggs.jpg|thumb|With eggs]]
Common ostriches become [[sexual maturity|sexually mature]] when they are 2 to 4 years old; females mature about six months earlier than males. As with other birds, an individual may [[Iteroparity|reproduce several times over its lifetime]]. The [[mating season]] begins in March or April and ends sometime before September. The mating process differs in different geographical regions. [[Territory (animal)|Territorial]] males typically [[mating call|boom]] (by inflating their neck) in defense of their territory and harem of two to seven hens;<ref name="Bertram 1992"/> the successful male may then mate with several females in the area, but will only form a pair bond with a 'major' female.<ref name="Bertram 1992"/>

The cock performs with his wings, alternating wing beats, until he attracts a mate. They will go to the mating area and he will maintain privacy by driving away all intruders. They graze until their behavior is synchronized, then the feeding becomes secondary and the process takes on a ritualistic appearance. The cock will then excitedly flap alternate wings again and start poking on the ground with his bill. He will then violently flap his wings to symbolically clear out a nest in the soil. Then, while the hen runs a circle around him with lowered wings, he will wind his head in a spiral motion. She will drop to the ground and he will mount for copulation.<ref name="Davies"/> Common ostriches raised entirely by humans may direct their courtship behavior not at other ostriches, but toward their human keepers.<ref name=BBC/>

<gallery mode="packed">
File:Ostriches Kgalagadi Transfrontier Park.jpeg|Only 15% of hatchling chicks reach 1 year of age.
File:Struthio camelus - Strausskueken.jpg|Chick|alt=Ostrich chick standing
File:2014-12-02 12h28 Ostrich Farm anagoria.JPG|Recently hatched from egg|alt=Chick, recently hatched from egg
File:Ostrich hen with chicks, northern Serengeti.jpg|Hen with chicks
File:Struthio camelus -Serengeti, Tanzania -female on nest-8.jpg|Female incubating eggs|alt=Female incubating eggs in a shallow nest on the ground
File:Struthio camelus - strus (2).JPG|Nest
</gallery>

[[File:Struthio camelus MWNH 0028.JPG|frameless|right|upright|alt=Egg]]
[[File:Struthio_camelus_egg.jpg|frameless|right|upright|alt=Fried egg]]
The female common ostrich lays her fertilized [[egg (biology)|eggs]] in a single communal nest, a simple pit, {{cvt|30|to|60|cm}} deep and {{cvt|3|m}} wide,<ref name=Harrison/> scraped in the ground by the male. The dominant female lays her eggs first; when it is time to cover them for incubation, she discards extra eggs from the weaker females, leaving about 20 in most cases.<ref name="Davies"/> A female common ostrich can distinguish her own eggs from the others in a communal nest.<ref name=Bertram1979/> Ostrich eggs are the largest of all eggs,<ref name=Hyde/> though they are actually the smallest eggs relative to the size of the adult bird – on average they are {{cvt|15|cm}} long, {{cvt|13|cm}} wide, and weigh {{cvt|1.4|kg}}, over 20 times the weight of a chicken's egg and only 1 to 4% the size of the female.<ref name=Perrins/> They are glossy cream-colored, with thick shells marked by small pits.<ref name="Nell 2003"/>

The eggs are incubated by the females by day and by the males by night. This uses the coloration of the two sexes to escape detection of the nest.  The drab female blends in with the sand, while the black male is nearly undetectable in the night.<ref name="Nell 2003"/> The [[Avian incubation|incubation]] period is 35 to 45 days, which is rather short compared to other [[ratite]]s. This is believed to be the case due to the high rate of predation.<ref name=Perrins/> Typically, the male defends the hatchlings and teaches them to feed, although males and females cooperate in rearing chicks. Fewer than 10% of nests survive the 9-week period of laying and incubation, and of the surviving chicks, only 15% of those survive to 1 year of age.<ref name=Perrins2/> However, among those common ostriches who survive to adulthood, the species is one of the longest-living bird species. Common ostriches in captivity have lived to 62 years and 7 months.<ref name = "Wood"/>

===Predators===
[[File:Ultime grida della savana (1975) - Cheetah hunting ostrich 2.png|thumb|Young female chased by a cheetah]]
As a flightless species in the rich biozone of the African savanna, the common ostrich faces a variety of formidable predators throughout its life cycle. Animals that prey on ostriches of all ages may include [[cheetah]]s, [[lion]]s, [[leopard]]s, [[African hunting dog]]s, and [[spotted hyena]]s.<ref name="Davies"/> Predators of nests and young common ostriches include [[Lupulella|jackal]]s, various [[birds of prey]], [[warthog]]s, [[mongoose]], and [[Egyptian vulture]]s.<ref name="Bertram 1992"/><ref name=Thouless/> Egyptian vultures have been known to hurl stones at ostrich eggs to crack them open so they can eat their contents.<ref>{{Cite web|url=https://www.researchgate.net/publication/230105897 |title=Egyptian Vultures ''Neophron percnopterus'' and Ostrich ''Struthio camelus'' eggs: the origins of stone-throwing behaviour|year=1987|website=ResearchGate}}</ref>

Due to predation pressure, common ostriches have many antipredator tactics. Though they can deliver formidable kicks, they use their great eyesight and speed to run from most of their predators.<ref name= Cooper/> Since ostriches that have detected predators are almost impossible to catch, most predators will try to ambush an unsuspecting bird using obstructing vegetation or other objects.<ref name="Bertram 1992"/> Some ostriches forage with other ostriches or mammals such as [[wildebeest]]s and zebras to detect predators more efficiently.<ref>Bertram, Brian CR. "Vigilance and group size in ostriches." Animal Behaviour 28.1 (1980): 278-286.</ref><ref name="Roots 2006"/> If the nest or young are threatened, either or both of the parents may create a distraction, feigning injury.<ref name=Perrins/> However, they may sometimes fiercely fight predators, especially when chicks are being defended, and are capable of killing humans, hyenas, and even lions in such confrontations.<ref name = Stewart2006/><ref name=NationalGeog/><ref>Austin, Oliver Luther. "Birds of the world; a survey of the twenty-seven orders and one hundred and fifty-five families." (1961).</ref><ref name=":5">{{cite journal |last1=Hurxthal |first1=Lewis M. |year=1986 |title=Our gang, ostrich style |journal=Natural History |volume=95 |pages=34–41, 94 |url=https://www.naturalhistorymag.com/htmlsite/master.html?https://www.naturalhistorymag.com/htmlsite/editors_pick/1986_12_pick.html }}</ref> In non-native areas, especially on ostrich farms in North America, adult ostriches have no known enemies due to their large size, intimidating presence and behaviour similar to that of overgrown guard dogs, with instances of them attacking and decapitating [[coyote]]s on one occasion.<ref>{{cite web|url=https://www.youtube.com/watch?v=PPQi8eIrYQs|title=Ostrich Decapitates Coyote!|author=Longhorn Lester's|website=YouTube|date=13 November 2023 }}</ref> 

Usually, ostrich hunting is done by male cheetah coalitions in the Kalahari region during the night, when ostrich's vigilance is less effective.<ref>Mills, M. G. L., and Margie Mills. Kalahari cheetahs: adaptations to an arid region. Oxford University Press, 2017.</ref> Cheetahs in other regions rarely hunt ostriches, but an exceptional coalition composed of three [[East African cheetah]]s has been reported in Kenya.<ref name = "Sunquist">Sunquist, Mel, and Fiona Sunquist. Wild cats of the world. University of Chicago Press, 2017.</ref><ref>{{Cite news|url=http://news.bbc.co.uk/earth/hi/earth_news/newsid_8302000/8302054.stm|title = Epic cheetah hunt filmed in HD|date = 12 October 2009}}</ref> Similarly, lions hunt ostriches mainly in the Kalahari region and not in other regions, or take ostriches as only a small percentage of their prey.<ref name = Sunquist/> Overall, due to their speed, vigilance, and possibly dangerous kick, ostriches are usually avoided by most predators, including lions, leopards, wild dogs, and cheetahs.<ref name=Hayward2005>{{Cite journal |last1=Hayward |first1=M. W. |last2=Kerley |first2=G. I. H. |year=2005 |title=Prey preferences of the lion (''Panthera leo'') |journal=Journal of Zoology |volume=267 |issue=3 |pages=309–322 |doi=10.1017/S0952836905007508 |url=http://www.zbs.bialowieza.pl/g2/pdf/1595.pdf |citeseerx=10.1.1.611.8271 }}</ref><ref name=Hayward2006>{{cite journal |last1=Hayward |first1=M.W. |last2=Henschel |first2=P. |last3=O'Brien |first3=J. |last4=Hofmeyr |first4=M. |last5=Balme |first5=G. |last6=Kerley |first6=G. I. H. |title=Prey preferences of the leopard (''Panthera pardus'') |journal=Journal of Zoology |date=2006 |volume=270 |issue=4 |pages=298–313 |doi=10.1111/j.1469-7998.2006.00139.x |url=http://www.ibs.bialowieza.pl/g2/pdf/1596.pdf |access-date=9 August 2021 |archive-date=29 February 2020 |archive-url=https://web.archive.org/web/20200229233750/https://ibs.bialowieza.pl/g2/pdf/1596.pdf |url-status=dead }}</ref><ref>Hayward, M.W., O’Brien, J., Hofmeyer, M. & Kerley, G.I.H.(2006b). Prey preferences of the cheetah (Acinonyx jubatus) (Felidae: Carnivora): morphological limitations or the need to capture rapidly consumable prey before Kleptoparasites arrive? J. Zool. (Lond.) doi: 10.1111/j.1469-7998.2006.00184.x.</ref><ref>Hayward, Matt W., et al. "Prey preferences of the African wild dog Lycaon pictus (Canidae: Carnivora): ecological requirements for conservation." Journal of Mammalogy 87.6 (2006): 1122-1131.</ref> Despite parental care, 90% is typical for chick mortality, most of it caused by predation.<ref name=":5"/>