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==Taxonomy==
English naturalist [[William John Burchell]] described the kori bustard in 1822. The specific epithet ''kori'' is derived from the [[Tswana language|Tswana]] name for this bird - ''Kgori''.<ref name= Williams/>
Two subspecies are currently recognized:
*''Ardeotis kori kori'' – the relatively pale nominate race from [[Botswana]], [[Zimbabwe]], [[Namibia]], southern [[Angola]], [[South Africa]] and [[Mozambique]].<ref name= Johnsgard/>
*''Ardeotis kori struthiunculus'' – the "Somali kori" distributed in [[Ethiopia]], [[Uganda]], [[South Sudan]], [[Kenya]] and [[Tanzania]]. The two races are separated by the miombo woodlands of central Africa.<ref name="HBW">{{cite book |title=[[Handbook of the Birds of the World]] |last1=del Hoyo |first1=J | last2=Elliot | first2 = A | last3=Sargatal | first3 = J | year=1996 |publisher=[[Lynx Edicions]] |___location=[[Barcelona]] |isbn=84-87334-20-2|volume=3}}</ref> This race has a more boldly patterned head and slightly more black and white patterning on the wings. The two races are similar in size, though ''A. k. struthiunculus'' may be slightly larger. This may be a distinct species.<ref name= Sinclair/>
== Descrizione ==
[[File:KoriBustardDavies.jpg|250px|thumbnail|Illustrazione di [[Claude Gibney Finch-Davies|C. G. Finch-Davies]] (1912).]]
=== Dimensioni ===
Il maschio di otarda kori misura 120-150 cm di lunghezza, 71-120 cm di altezza e può raggiungere un'apertura alare di 230-275 cm. Pesa generalmente tra i 7 e i 18 kg. Il peso medio di 20 maschi adulti catturati in [[Namibia]] e appartenenti alla sottospecie nominale era di 11,3 kg, mentre i maschi di ''A. k. struthiunculus'' pesano mediamente 10,9 kg. Esemplari particolarmente grandi, tuttavia, possono raggiungere i 16-19 kg, e in alcuni casi eccezionali pesare almeno 20 kg<ref name=NatZoo/><ref name=Nationalzoo>{{cita web|url=http://nationalzoo.si.edu/SCBI/tropicalecosystems/koribustards/default.cfm|titolo=Kori Bustard Research|editore=National Zoo, FONZ: Washington D.C.|accesso=26 luglio 2013}}</ref><ref name="CRC">''CRC Handbook of Avian Body Masses'' a cura di John B. Dunning Jr. (1992). CRC Press (1992), {{ISBN|978-0-8493-4258-5}}.</ref><ref name= "CRC2">''CRC Handbook of Avian Body Masses, 2nd Edition'' a cura di John B. Dunning Jr. (2008). CRC Press, {{ISBN|978-1-4200-6444-5}}.</ref>. Sono stati riportati casi di esemplari fuori dal comune del peso di 23<ref name=Newman/>, 34<ref name="Wood">{{cita libro|autore=Gerald Wood|titolo=The Guinness Book of Animal Facts and Feats|anno=1983|isbn=978-0-85112-235-9}}</ref> e perfino «quasi» 40 kg<ref>M. Main (1987) ''Kalahari: Life's Variety in Dune and Delta''. Southern Book Publishers (Pty) Limited, Johannesburg.</ref>, ma nessuna di queste dimensioni straordinarie è mai stata verificata e in alcuni casi potrebbero provenire da fonti inaffidabili. Tra le otarde, solamente il maschio dell'otarda eurasiatica (''[[Otis tarda]]'') può raggiungere un peso simile; con tali dimensioni, i maschi di otarda kori e di quella eurasiatica sono non solamente i rappresentanti più grandi della loro famiglia, ma anche, probabilmente, gli animali volatori viventi più pesanti. Se si tenesse conto del peso medio tra i due sessi, infatti, altre specie, come il pellicano riccio (''[[Pelecanus crispus]]''), il condor delle Ande (''[[Vultur gryphus]]'') e il cigno trombettiere (''[[Cygnus buccinator]]''), raggiungerebbero pesi maggiori, ma nessuna di queste presenta un dimorfismo sessuale così pronunciato come le otarde giganti<ref name="CRC"/><ref name="Wood"/>. Le femmine di otarda kori pesano in media 4,8-6,1 kg, spaziando da un minimo di 3 a un massimo di 7 kg. Il peso medio di 35 femmine adulte catturate in [[Namibia]] appartenenti alla sottospecie nominale era di 5,62 kg, mentre le femmine di ''A. k. struthiunculus'' pesano in media 5,9 kg<ref name="CRC2"/>. Le femmine misurano 80-120 cm di lunghezza, sono alte in media 60 cm e hanno un'apertura alare di 177-220 cm. The standard measurements of the male include a [[Wing chord (biology)|wing chord]] of {{convert|69.5|to|83|cm|in|abbr=on}}, a [[tail]] measures from {{convert|35.8|-|44.7|cm|in|abbr=on}}, a [[Culmen (bird)|culmen]] from {{convert|9.5|to|12.4|cm|in|abbr=on}} and a [[Tarsus (skeleton)|tarsus]] from {{convert|20|to|24.7|cm|in|abbr=on}}. Meanwhile, the female's standard measurements are a [[Wing chord (biology)|wing chord]] of {{convert|58.5|to|66.5|cm|in|abbr=on}}, a [[tail]] of {{convert|30.7|to|39.5|cm|in|abbr=on}}, a [[Culmen (bird)|culmen]] from {{convert|7|to|10.4|cm|in|abbr=on}} and a [[Tarsus (skeleton)|tarsus]] from {{convert|16|to|19.5|cm|in|abbr=on}}.<ref name= Johnsgard>Johnsgard, Paul A. 1990. ''Bustards: Stalkers of the Dry Plains''. Zoonooz 63(7): 4-11.</ref><ref name=Nationalzoo/><ref name="CRC"/><ref name="Wood"/><ref>[http://ecoport.org/ep?Bird=89231&entityType=BI****&entityDisplayCategory=BI****1000|Kori Bustard profile] (2011).</ref> Body mass can vary considerably based upon rain conditions.<ref name= Liversidge>Liversidge, R. 1991. ''The Birds Around Us - Birds of the Southern African Region''. Fontein Publishing Company (Pty) Ltd., Parklands.</ref>
=== Aspetto ===
L'otarda kori presenta una colorazione criptica, prevalentemente grigia e marrone, finemente macchiata di bianco e nero. Le parti superiori e il collo sono fittamente vermicolati di nero e di ''beige''-grigiastro<ref name= Williams>J. G. Williams (1995) ''Collins Field Guide: Birds of East Africa''. HarperCollins, Hong Kong.</ref>. Sulla parte ventrale il piumaggio appare più sgargiante, con zone bianche, nere e ''beige''. La cresta sulla testa è di colore nerastro, meno pronunciato nella femmina. Sopra l'occhio è presente una striscia bianca simile a un sopracciglio. Il mento, la gola e il collo sono biancastri, con sottili e delicate barrature nere<ref name=Newman/>. Un collare nero alla base della parte posteriore del collo si estende fin sui lati del petto<ref name=Alden>P. C. Alden, R. D. Estes, D. Schlitter e B. McBride (1996) ''Collins Guide to African Wildlife''. HarperCollins Publishers, Londra.</ref>. Le piume intorno al collo sono lasse, e tale caratteristica fa sì che il collo sembri più largo di quanto non sia in realtà<ref name= Birdlife>''Birdlife in southern Africa'' a cura di K. Newman (1971). Macmillan, Johannesburg, Sudafrica.</ref>. Il ventre è bianco e la coda presenta larghe fasce di colore grigio-brunastro e bianco<ref name=Williams/>. Le piume contengono porfirine sensibili alla luce, che conferiscono ad esse una sfumatura rosea alla base - particolarmente evidente quando vengono allargate improvvisamente<ref name=NatZoo/>. La testa è larga e le zampe sono relativamente lunghe. L'iride è di colore giallo chiaro, mentre il becco, relativamente lungo, diritto e piuttosto appiattito alla base, è color corno-verdastro chiaro. Le zampe sono giallastre. I piedi presentano tre dita rivolte in avanti<ref name=Newman/>. Le femmine hanno un piumaggio simile a quello del maschio, ma sono molto più piccole: misurano circa il 20-30% in meno e spesso pesano 2-3 volte meno del maschio. Presentano inoltre zampe e collo più sottili<ref name=Newman>K. Newman (1992) ''Newman's Birds of Southern Africa: Expanded Edition, Fourth Edition''. Southern Book Publishers (Pty) Ltd., Halfway House.</ref>. I giovani sono simili nell'aspetto alla femmina, ma presentano una colorazione dai toni più brunastri e un maggior numero di macchie sul dorso, oltre a cresta e piume del collo più corte<ref name=Maclean/>. I giovani maschi sono più grandi delle femmine e possono avere dimensioni paragonabili a quelle di un maschio adulto, ma tendono ad essere meno corpulenti; si differenziano inoltre per il fatto di avere un collo più sottile, una cresta sulla testa più breve, occhi più chiari e dorso più scuro<ref name=NatZoo/>.
===Similar
The size and dark crest are generally diagnostic amongst the bustards found in the kori bustard's range.<ref name= Sasol>Sinclair I., Hockey P. & Tarboton W. 1997. ''Sasol Birds of Southern Africa''. Struik Publishers (Pty) Ltd., Cape Town.</ref> However, [[East Africa]] holds the greatest diversity of bustards anywhere, including some other quite large species, and these have the potential to cause confusion. Kori bustards are distinguished from [[Denham's bustard]] (''Neotis denhamii'') and [[Ludwig's bustard]] (''Neotis luwigii''), both of which they sometimes forage with, by their greyer appearance and by their lack of a tawny red hind-neck and upper mantle. In flight it can be distinguished from both of these somewhat smaller bustards by not displaying any white markings on the upperwing, which is uniformly grey here. Both Stanley's and Ludwig's bustards lack the kori's dark crest.<ref name= Williams/><ref name= Ginn/><ref name= Sasol/> More similar to, and nearly the same size as, the kori is the closely related [[Arabian bustard]] (''Ardeotis arabs'') (despite its name, the latter species ranges well into [[East Africa]]). However, the Arabian species has white-tipped wing coverts, a browner back and very fine neck vermiculations and also lacks the black base to the neck and the black in the wing coverts as seen in the kori.<ref name= Williams/><ref name= Sinclair/>
==Distribution and habitat==
[[File:Koribustard.jpg|thumb|left|''A. k. struthiunculus'' in [[Amboseli]], [[Kenya]]]]
The kori bustard is found throughout southern Africa, except in densely wooded areas. They are common in [[Botswana]] and [[Namibia]], extending into southern [[Angola]] and marginally into southwestern [[Zambia]]. In [[Zimbabwe]] they are generally sparse but locally common, particularly on the central plateau. Their distribution range extends along the [[Limpopo River]] valley into southern [[Mozambique]] and the eastern lowveld of [[South Africa]]. In South Africa they are also infrequent to rare in the [[Free State (province)|Free State]], [[North West (South African province)|North West]] and [[Northern Cape|Northern Cape Province]]s, extending southwards into the interior of the [[Western Cape|Western]] and [[Eastern Cape|Eastern Cape Provinces]]. Kori bustards are absent from the coastal lowlands along the south and east of South Africa and from high mountainous areas. This species is common in [[Tanzania]] at [[Ngorongoro National Park]], [[Kitulo National Park]] and [[Serengeti National Park]]. A geographically disjunct population also occurs in the deserts and savanna of northeastern Africa. Here, the species ranges from extreme southeast [[South Sudan]], north [[Somalia]], [[Ethiopia]] through all of [[Kenya]] (except coastal regions), [[Tanzania]] and [[Uganda]].<ref name= Sinclair>Sinclair I. & Ryan P. 2003. ''A comprehensive illustrated field guide : Birds of Africa south of the Sahara''. Struik Publishers, Cape Town.</ref> Kenya may hold the largest population of kori bustards of any country and it can even border on abundant in the [[North Eastern Province, Kenya|North Eastern Province]].<ref name= Ginn/> They are usually residential in their range, with some random, nomadic movement following rainfall.<ref name= Ginn>Ginn P.J., McIlleron W.G. & Milstein P. le S. 1989. ''The Complete Book of southern African birds''. Struik Winchester, Cape Town.</ref>
This species occurs in open grassy areas, often characterized by sandy soil, especially [[Kalahari Desert|Kalahari sands]], and short grass usually near the cover of isolated clumps of trees or bushes.<ref name= Ginn/> It may be found in plains, arid plateaus, [[Highveld|highveld grassland]], arid scrub, lightly wooded savanna, open dry [[bushveld]] and semi-desert.<ref name= Maclean>Maclean, G.L. 1993. ''Robert's Birds of Southern Africa. Sixth Edition''. John Voelcker Bird Book Fund, Cape Town.</ref> Where this species occurs, annual rainfall is quite low, between {{convert|100|and|600|mm|in|abbr=on}}.<ref name= Maclean/> Breeding habitat is savanna in areas with sparse grass cover and scattered trees and shrubs. When nesting they sometimes use hilly areas.<ref name= Tarboton>Tarboton W. 2001. ''A Guide to the Nests and Eggs of Southern African Birds''. Struik Publishers (Pty) Ltd., Cape Town.</ref> They follow fires or herds of foraging ungulates, in order to pick their various foods out of the short grasses. They may also be found in cultivated areas, especially wheat fields with a few scattered trees.<ref name= Ginn/> This bustard is not found in well-wooded and forested areas due to the fact that it needs a lot of open space in which to take off.<ref name= Ginn/> In arid grassland areas it is found along dry watercourses where patches of trees offer shade during the heat of the day.<ref name= NatZoo>{{cite web |url=http://nationalzoo.si.edu/SCBI/TropicalEcosystems/KoriBustards/biology.cfm# |title=Smithsonian Conservation Biology Institute- Kori Bustard |first=Sara|last=Hallager |publisher=The Smithsonian Institution |accessdate=2013-08-30}}</ref>
[[File:Ardeotis kori portrait.jpg|thumb|left|A close-up of the plumage of a captive male]]
==Behaviour==
[[File:Kori Bustard at Maasai Mara.jpg|400px|thumb|right|Male ''A. k. struthiunculus'' at [[Maasai Mara]], [[Kenya]]]]
Kori bustards spend most of their time on the ground, with up to 70% of their time being on foot,<ref name= Williams/> although they do occasionally forage in low bushes and trees. There is a lone report of a bird sighted in Kenya perched at the top of a tree.<ref>L. Hudson, pers. comm</ref> This bustard is a watchful and wary bird. Their behavior varies however, and they are usually very shy, running or crouching at the first sign of danger; at other times they can be completely fearless of humans.<ref name= Williams/> They have a hesitant, slow manner of walking, and when they detect an intruder they try to escape detection by moving off quietly with the head held at an unusual angle of between 45° and 60°.<ref name= Ginn/> Being a large and heavy bird, it avoids flying if possible. When alarmed it will first run and, if pushed further, will take to the air on the run with much effort, its wings making heavy wingbeats. Once airborne it flies more easily with slow, measured wingbeats, with the neck extended and the legs folded. It usually remains low and lands again within sight.<ref name= Liversidge/> When they land, kori bustards keep their wings spread and only fold them when the bird has slowed down to a walking speed.<ref name= Ginn/> Kori bustards have no preen gland, so to keep clean, they produce a powder down. Sun bathing and dust bathing are practiced.<ref name= NatZoo/> This bird has a loud, booming [[mating call]] which is often uttered just before dawn and can be heard from far away. Mostly residential, kori bustards may engage in nomadic movements.<ref name= Sasol/> These migratory movements are probably influenced by rainfall and there is no evidence suggesting any regular pattern. These local migrations take place at night but have not been mapped. In the [[Etosha National Park]] these birds have been recorded moving up to {{convert|85|km|mi|abbr=on}} from [[mopane]] woodland to open grassland plains and returning again the following season.<ref name= Ginn/> Trial satellite tagging of one male kori bustard by the [[National Museums of Kenya]] demonstrated a migration along the [[East African Rift|Rift Valley]] between [[Tanzania]] and southeastern [[South Sudan]].<ref>Njoroge, P. and Launay, F.. 1998. ''Satellite Tracking of Kori bustards Ardeotis kori in Kenya''. Scopus 20: 19-22.</ref> Additionally, adult and juvenile males move after the breeding season, whereas females do not appear to do so.<ref name= Harrison/> Generally the kori bustard feeds during the morning and in the evening, spending the rest of the day standing still in any available shade.<ref name= Ginn/>
===
Less vocal than other bustards, the kori bustard is generally silent but, when alarmed, both sexes emit a loud growling bark. This is described as a ''ca-caa-ca'' call, repeated several times for up to 10 minutes. This call carries long distances. This call is most often given by females with young and males during agnostic encounters.<ref name= Williams/> Chicks as young as two weeks will also emit this alarm call when startled.<ref name= NatZoo/> The male's mating call is a deep, resonant ''woum-woum-woum-woum''<ref name= Ginn/> or ''oom-oom-oom''<ref name= Sinclair/> or ''wum, wum, wum, wum, wummm''.<ref name= Newman/> This call ends with the bill snapping which is only audible at close range.<ref name= Ginn/> Outside of the breeding display, kori bustards are often silent. A high alarm call, generally uttered by females, is sometimes heard. They may utter a deep ''vum'' on takeoff.<ref name= Maclean/>
===Sociality===
During the mating season, these birds are usually solitary but for the breeding pair. Otherwise, they are somewhat gregarious, being found in groups often including 5 to 6 birds but occasionally groups can number up to 40 individuals. Larger groups may be found around an abundant food source or at watering holes. In groups, birds are often fairly far apart from each other, often around a distance of {{convert|100|m|ft|abbr=on}}. Foraging groups are often single-sex. Such groups do not last long and often separate after a few days. These groups are believed advantageous both in that they may ensure safety in numbers against predation and may bring the bustards to prime food sources.<ref name= Sinclair/>
==
[[File:Ardeotis kori.jpg|thumb|Female of the nominate race near [[Etosha National Park]], [[Namibia]].]]
Walking slowly and sedately, they forage by picking at the ground with the bills and are most active in the first and last hours of daylight. Kori bustards are quite omnivorous birds. [[Insect]]s are an important food source, with common species such as [[locust]]s, [[grasshopper]]s, [[dung beetle]]s (''Scarabaeus'' ssp.) and [[caterpillar]]s being most often taken. They may follow large ungulates directly to catch insects flushed out by them or to pick through their dung for edible invertebrates. During outbreaks of [[locust]]s and [[caterpillar]]s, kori bustards are sometimes found feeding on them in numbers. Other insect prey can include [[bush-cricket]]s (''Tettigonia'' ssp.), [[termite]]s, [[hymenoptera]]ns and [[Solifugae|solifuges]]. [[Scorpion]]s and [[mollusc]]s may be taken opportunistically as well.<ref name= Ginn/>
Small vertebrates may also be taken regularly, including [[lizard]]s, [[chameleon]]s, small [[snake]]s, small [[mammal]]s (especially [[rodent]]s) and bird eggs and nestlings. They may occasionally eat [[carrion]], especially from large animals killed in veld fires. Plant material is also an important food. [[Grass]]es and their [[seed]]s are perhaps the most prominent plant foods, but they may also eat [[seed]]s, [[berries]], [[root]]s, [[bulb]]s, [[flower]]s, wild [[melon]]s and green [[leaf|leaves]]. This bustard is very partial to ''[[Acacia]]'' gum. This liking has given rise to the Afrikaans common name ''Gompou'' or, literally translated, "gum peacock".<ref name= Ginn/> They drink regularly when they can access water but they can be found as far as {{convert|40|km|mi|abbr=on}} from water sources.<ref name= Ginn/> Unusually, they suck up rather than scoop up water.<ref name= Harrison/>
===Breeding===
[[File:Kori bustard bird - Ngorongoro-2.jpg|thumb|right|Male kori bustard (''A. k. struthiunculus'') displaying in [[Ngorongoro Conservation Area]].]]
[[File:Ardeotis kori MWNH 0044.JPG|thumb|Egg, Collection [[Museum Wiesbaden]]]]
Kori bustards' breeding season is different between the two subspecies. In general, ''A. k. struthiunculus'' breeds from December to August and ''A. k. kori'' breeds from September to February.<ref name= Harrison>Harrison, J., D. Allan, L. Underhill, M. Herremans, A. Tree, V. Parker, C. Brown. 1997. ''The atlas of southern African birds. Vol. 1: Non-passerines''. Johannesburg: BirdLife South Africa.</ref> Breeding is closely tied with rainfall, and in drought years, may be greatly reduced or not even occur.<ref name= Osborne>Osborne, T. and Osborne, L.. ''Ecology of the Kori bustard in Namibia''. Annual Report of the Ministry of Environment and Tourism Permit Office, Namibia. Feb. 1998.</ref>
Kori bustards engage in [[lek mating]]. All bustards have [[polygynous]] breeding habits, in which one male displays to attract several females, and mates with them all.<ref name= Hallager>Hallager, S., J. Boylan. 2004. ''Kori Bustard Species Survival Plan Husbandry Manual''</ref> Males display at regularly used sites, each male utilizing several dispersed leks or display areas. These displays usually take place in the mornings and evenings. The courtship displays of the males are impressive and elaborate, successfully advertising their presence to potential mates.<ref name= Tarboton/> The males hold their heads backwards, with cheeks bulging, the crest is held erect, the bill open and they inflate their gular pouches, forming a white throat "balloon". During this display the oesophagus inflates to as much as four times its normal size and resembles a balloon. They also puff out their frontal neck feathers which are splayed upwards showing their white underside. The white may be visible up to {{convert|1|km|mi|abbr=on}} away during display.<ref name= Hallager/> Their wings are drooped and their tails are raised upwards and forwards onto their backs like a [[turkey (bird)|turkey]], the retrices being held vertically and their undertail coverts fluffed out. They enhance their performance with an exaggerated bouncing gait. When displaying they stride about with their necks puffed out, their tail fanned and their wings planed and pointed downward.<ref name= Steyn/> They also emit a low-pitched booming noise when the neck is at maximum inflation and snap their bills open and shut. Several males dispersed over a wide area gather to display but usually one is dominant and the others do not display in his presence and move away. The displaying males are visited by the females who presumably select the male with the most impressive display.<ref>Dennis N., Knight M., Joyce P. 1997. ''The Kalahari: Survival in a Thirstland Wilderness''. Struik Publishers (Pty) Ltd., Cape Town.</ref> Occasionally fights between males can be serious during the mating season when display areas are being contested, with the two competitors smashing into each other's bodies and stabbing each other with their bills. They may stand chest-to-chest, tails erect, bills locked and 'push' one another for up to 30 minutes.<ref name= Maclean/>
Following the display, the copulation begins with the female lying down next to the dominant displaying male. He stands over her for 5–10 minutes, stepping from side to side and pecking her head in a slow, deliberate fashion, tail and crest feathers raised. She recoils at each peck. He then lowers himself onto his tarsi and continues pecking her until he shuffles forward and mounts with wings spread. Copulation lasts seconds after which both stand apart and ruffle their plumage. The female then sometimes barks and the male continues with his display.<ref name= Tarboton/><ref name= NatZoo/>
As with all bustards, the female makes no real nest. The female kori bustard lays her eggs on the ground in a shallow, unlined hollow, rather than the typical scrape. This nest is usually located within {{convert|4|m|ft|abbr=on}} of a tree or shrub, termite mound or an outcrop of rocks. The hollow may measure {{convert|300|-|450|mm|in|abbr=on}} in diameter and be almost completely covered by the female when she's incubating.<ref name= Tarboton/> Due to their ground ___location, nests are often cryptic and difficult for a human to find, unless stumbled onto by chance.<ref name= Tarboton/> The same site is sometimes reused in successive years. The kori bustard is a solitary nester and there is no evidence of territoriality amongst the females.<ref name= Tarboton/> Usually two eggs are laid, though seldom 1 or 3 may be laid. Clutch size is likely correlated to food supply.<ref name= Tarboton/><ref name= Osborne/> They are cryptically colored with the ground color being dark buff, brown or olive and well marked and blotched with shades of brown, grey and pale purple. Eggs are somewhat glossy or waxy and have a pitted-looking surface. Egg size is {{convert|81|to|86|mm|in|abbr=on}} in height and {{convert|58|to|61|mm|in|abbr=on}} width. The eggs weigh individually about {{convert|149|g|oz|abbr=on}}, with a range of {{convert|121|to|178|g|oz|abbr=on}}.<ref name= Ginn/><ref name= Tarboton/><ref name= Hallager/>
The female, who alone does all the brooding behavior without male help, stays at the nest 98% of the time, rarely eating and never drinking.<ref name= Steyn>Steyn, P. 1996. ''Nesting Birds : The breeding habits of southern African birds''. Fernwood Press, Vlaeberg.</ref> Occasionally she stretches her legs and raises her wings overhead. The female regularly turns the eggs with her bill. The female's plumage is drab and earth-colored, which makes her well camouflaged. She occasionally picks up pieces of vegetation and drops them on her back to render her camouflage more effective.<ref name= Tarboton/> If they need to feed briefly, the females go to and from the nest with a swift, silent crouching walk.<ref name= Steyn/> If approached the incubating bird either slips unobtrusively from the nest or sits tight, only flying off at the last moment.<ref name= Tarboton/> The incubation period is 23 to 30 days, though is not known to exceed 25 days in wild specimens.<ref name= Steyn/> The young are [[precocial]] and very well camouflaged. The lores are tawny, the crown tawny mottled black. A broad white supercilium bordered with black meets on the nape, extending down the centre of the nape. The neck is white with irregular black stripes from behind the eye and from the base of the lower mandibles. The upper parts are tawny and black with 3 black lines running along the back. The underparts are whitish.<ref name= Tarboton/> When the chicks hatch, the mother brings them a steady stream of food, most of it soft so the chicks can eat it easily.<ref>{{cite journal|title=A Description of Commonly Observed Behaviors for the Kori Bustard (Ardeotis Kori)|author1=Lichtenberg, Elinor M. |author2=Hallager, Sara |year=2007 | journal=Journal of Ethology| volume=26|issue=1|pages=17–34 |hdl=10088/6028| doi=10.1007/s10164-006-0030-z}}</ref> Captive hatchlings weigh {{convert|78|to|116|g|oz|abbr=on}} on their first day but grow quickly.<ref name= Hallager/> The precocial chicks are able to follow their mother around several hours after hatching.<ref name= NatZoo/> After a few weeks, the young actively forage closely with their mothers. They fledge at 4 to 5 weeks old, but are not self-assured fliers until 3 to 4 months.<ref name= Maclean/> On average, around 67% of eggs successfully hatch (testimony to the effective camouflage of nests) and around one of the two young survive to adulthood. In [[Namibia]] and [[Tanzania]], breeding success has been found to be greatly reduced during times of drought.<ref name= Osborne/> Most young leave their mothers in their second year of life, but do not start breeding until they are fully mature at three to four years old in both sexes in studies conducted both of wild and captive bustards.<ref name= Maclean/><ref name= NatZoo/> The lifespan of wild kori bustards is not known but they may live to at least 26 or possibly 28 years old in captivity.<ref name= NatZoo/><ref name= Hallager/>
===Interspecies interactions===
[[File:Ardeotis kori flying.JPG|thumb|''Ardeotis kori kori'' flying near [[Windhoek]], [[Namibia]].]]
The kori bustard is often found in areas with a large quantity of antelope and other game. In Tanzania, kori bustards regularly attend [[blue wildebeest]] (''Connochaetes taurinus'') herds and feed on the small mammals and insects disturbed by them.<ref>Dean W.R.J. & MacDonald, I.A.W. 1991. ''A review of African birds feeding in association with mammals''. Ostrich 52:135-155.</ref> Sometimes kori bustards are found with [[southern carmine bee-eater]]s (''Merops nubicoides'') and [[northern carmine bee-eater]]s (''Merops nubicus'') riding on their backs as they stride through the grass.<ref>Mikula, P. & Tryjanowski, P. 2016. ''Internet searching of bird–bird associations: a case of bee-eaters hitchhiking large African birds''. Biodiversity Observations 7.80: 1-6.</ref> The bee-eaters make the most of their walking perch by hawking [[insect]]s from the bustard's back that are disturbed by the bustard's wandering. This is regularly seen in [[Chobe National Park]], [[Botswana]] but has only been reported once elsewhere. There is also one record of [[fork-tailed drongo]]s (''Dicrurus adsimilis'') perching on their backs in a similar manner.<ref name= Ginn/> Kori bustards have been observed to behave aggressively to non-threatening animals at watering holes, as they may raise their crests, open their wings and peck aggressively. They have been seen acting aggressively towards [[red-crested korhaan]]s (''Eupodotis ruficrista''), [[springbok]] (''Antidorcas marsupialis''), [[plains zebra]] (''Equus quagga''), and [[gemsbok]] (''Oryx gazella'').<ref name= Ginn/> When kept in captivity, kori bustards have been kept together with numerous other (typically African) species in close quarters. Fifteen other bird species and 12 mammals successfully cohabitated with them (including [[rhinoceros]]). However, the bustards sometimes injure or kill the young of everything from [[waterfowl]] to [[dik-dik]]s and may be killed by larger species from [[ostrich]]es (''Struthio camelus'') to [[zebra]]s (''Equus'' spp.).<ref name= Hallager/>
Being a large, ground-dwelling bird species, the kori bustard is vulnerable to many of Africa's myriad of formidable terrestrial predators. [[Leopard]]s (''Panthera pardus''), [[caracal]]s (''Caracal caracal''), [[cheetah]]s (''Acinonyx jubatus''), [[lion]]s (''Panthera leo''), [[spotted hyena]] (''Crocuta crocuta''), [[Python sebae|African rock pythons]] (''Python sebae''), [[jackal]]s (''Canis'' spp.), [[Verreaux's eagle]] (''Aquila verreauxii''), [[martial eagle]]s (''Polemaetus bellicosus''), and [[Verreaux's eagle-owl]]s (''Bubo lacteus'') are amongst their potential natural predators. Additionally, [[warthog]]s (''Phacochoerus spp.''), [[tawny eagle]]s (''Aquila rapax''), [[Cape eagle-owl]]s (''Bubo capensis''), [[mongoose]]s and [[baboon]]s (''Papio'' spp.) may eat eggs, small chicks, and in the case of the tawny eagle and the Cape eagle-owl sometimes adults.<ref name= Ginn/><ref name= NatZoo/><ref name= Hallager/> When alarmed, kori bustards make barking calls and bend forward and spread their tail and wings to appear larger.<ref name= NatZoo/> Adults will growl when their young are threatened by predators.<ref name= Harrison/> Chicks tend to be the most vulnerable to predators by far. Many, despite their cryptic camouflage and the mother's defenses, are regularly picked off by jackals and leopards at night.<ref name= Ginn/> Up to 82% of kori bustard chicks die in their first year of life.<ref name= Osborne/> When found with carmine bee-eaters, the smaller birds may incidentally provide some protection from predators due to their vigilance.<ref>Jackson, T.H.E.. 1945. ''Some Merops-Ardeotis Perching Associations in Northern Kenya''. Ibis 87: 284-286.</ref> The display of the adult male may make it more conspicuous to larger predators, such as hyenas or lions.<ref name= Tarboton/> A shock display may be performed when a bird is alarmed. While too large to be prey for most predatory birds, it is known that the martial eagle is a serious natural enemy even for adult bustards. In one documented attack by a martial eagle on an adult kori bustard, both birds ended up wounded, the eagle with a bleeding leg from the bustard's counterattack, but the bustard more seriously injured, with a broken wing and several open wounds. Although it walked away, the injured bustard in the confrontation was found dead the next morning, being fed on by a jackal.<ref>{{cite web |url=http://www.birdforum.net/showthread.php?t=180293 |title=Martial Eagle Attack a Kori Bustard in South Africa |publisher=BirdForum |accessdate=2013-07-26}}</ref>
==Status==
[[File:RMKenya1915.png|thumb|right|[[Richard Meinertzhagen]] holds a shot kori bustard near [[Nairobi]] in 1915, illustrating the bird's huge size.]]
The kori bustard is generally a somewhat scarce bird. [[CITES#Appendix II|Appendix II of CITES]] and the ''2000 Eskom Red Data Book for Birds'' lists the status of the nominate race as Vulnerable, estimating that in the next three generations, it is expected to decline by 10% in [[South Africa]].<ref name= Maclean/><ref>Barnes, K.N. (ed.) 2000. ''The Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland''. Birdlife South Africa.</ref> In protected areas, they can be locally common.<ref name= Sinclair/> Viable populations exist in unprotected areas as well (e.g. [[Ethiopia]] and [[Sudan]], and in [[Tanzania]] around [[Lake Natron]] and in the foothills of [[Mount Kilimanjaro]]) but in these areas, the birds are hunted.<ref name= NatZoo/> They have been much reduced by hunting, having been traditionally snared in ''Acacia'' gum baits and traps. Although no longer classified as game birds, they are still sometimes eaten.<ref name= Newman/> In [[Namibia]], they are indicated as game as they are called the “Christmas turkey” and in South Africa, the “Kalahari Kentucky".<ref name= NatZoo/><ref name= Osborne/> Hunting of bustards is difficult to manage.
The kori bustard is now generally uncommon outside major protected areas. Habitat destruction is a major problem for the species, compounded by bush encroachment due to overgrazing by livestock and agricultural development.<ref>Ottichilo, W., De Leeuw, J., Skidmore, A., Prins, H., and Said, M. 2000. ''Population trends of large non-migratory wild herbivores and livestock in the Masai Mara ecosystem, Kenya, between 1977 and 1997''. African Journal of Ecology 38: 202-216.</ref> Poisons used to control locusts may also effect and collisions with overhead power wires regularly claim kori bustards.<ref name= Sinclair/> One {{convert|10|km|mi|abbr=on}} stretch of overhead powerlines in the [[Karoo]] killed 22 kori bustards during a five-month period.<ref name= NatZoo/> Kori bustards tend to avoid areas used heavily by humans.<ref>Lichtenberg, E.M. and Hallager, S. (2008) ''A description of commonly observed behaviors for the kori bustard (Ardeotis kori)''. Journal of Ethology, 26: 17-34.</ref> Nonetheless, because it has such a large range and its rate of decline is thought to be relatively slow, the kori bustard is not currently listed in a threatened category on the IUCN Red List.
The species is prominent in many native African cultures, variously due to its imposing, impressive size, spectacular displays by adult males or the cryptic nature of the nesting female. The kori bustard features in dances and songs of the [[Bushmen|San people]] of [[Botswana]], and paintings of these bustards feature in ancient San rock art.<ref name= Sinclair/> It was associated with royalty in Botswana since they reserved it for their own consumption, and since 2014 it is also the [[List of national birds|national bird]] of Botswana.<ref name="pel">{{cite news |last1=Pelontle |first1=Kedirebofe |title=Department unveils national symbols |url=http://www.dailynews.gov.bw/news-details.php?nid=11294 |accessdate=12 July 2016 |work=DailyNews |agency=Botswana Press Agency (BOPA) |date=13 May 2014}}</ref>
== Altri progetti ==
Riga 110 ⟶ 124:
== Collegamenti esterni ==
* {{cita web|url=http://ibc.hbw.com/ibc/phtml/especie.phtml?idEspecie=1334|titolo=Documenti video sull'otarda di Kori}}
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