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{{Tassobox
|nome=Giraffa
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The '''giraffe''' (''Giraffa camelopardalis'') is an [[Africa]]n [[even-toed ungulate]] [[mammal]], the [[Largest mammals#Even-toed Ungulates .28Artiodactyla.29|tallest]] [[Extant taxon|living]] terrestrial animal and the largest [[ruminant]]. Its [[binomial nomenclature|species name]] refers to its [[camel]]-like appearance and the patches of color on its fur. Its chief distinguishing characteristics are its extremely long neck and legs, its horn-like [[ossicone]]s and its distinctive coat patterns. It stands {{convert|5|–|6|m|abbr=on}} tall and has an average weight of {{convert|1600|kg|lb|abbr=on}} for males and {{convert|830|kg|lb|abbr=on}} for females. It is classified under the [[Family (biology)|family]] [[Giraffidae]], along with its closest extant relative, the [[okapi]]. There are nine subspecies, which are distinguished by their coat patterns.
The giraffe's scattered range extends from [[Chad]] in the north to [[South Africa]] in the south, and from [[Niger]] in the west to [[Somalia]] in the east. Giraffes usually inhabit [[savanna]]s, [[grassland]]s, and open [[woodland]]s. Their primary food source is [[acacia]] leaves, which they can browse at heights that most other herbivores cannot reach. Giraffes are preyed on by [[lion]]s, and calves are also targeted by leopards, [[spotted hyena]]s and [[Lycaon pictus|wild dog]]s. Adult giraffes do not have strong social bonds, though they do gather in loose aggregations if they happen to be moving in the same general direction. Males establish social hierarchies through "necking", which are combat bouts where the neck is used as a weapon. [[dominance (ethology)|Dominant]] males gain mating access to females, who bear the sole responsibility for raising the young.
The giraffe has intrigued various cultures, both ancient and modern, for its peculiar appearance, and has often been featured in paintings, books and cartoons. It is classified by the [[International Union for Conservation of Nature]] (IUCN) as [[Least Concern]], but has been [[extirpated]] from many parts of its former range, and some subspecies are classified as [[Endangered]]. Nevertheless, giraffes are still found in numerous [[national park]]s and [[game reserve]]s.
==Etymology==
The name ''giraffe'' has its earliest known origins in the [[Arabic language|Arabic]] word ''zarafa'' (زرافة), perhaps from some African language.<ref name=OED/> The name is translated as "fast-walker".<ref name=kingdon/> There were several [[Middle English]] spellings such as ''jarraf'', ''ziraph'', and ''gerfauntz''.<ref name=OED/> It is also possible that the word was derived from the animal's [[Somali language|Somali]] name ''Geri''.<ref>{{cite book|author=Peust, C.|contribution=Some Cushitic Etymologies|editors=Dolgopolʹskiĭ, A.; Takács, G.; Jungraithmayr, H|year=2009|title=Semito-Hamitic Festschrift for A.B. Dolgopolsky and H. Jungraithmayr|publisher=Reimer|pages=257–60|isbn=3-496-02810-6}}</ref> The [[Italian language|Italian]] form ''giraffa'' arose in the 1590s.<ref name=OED>{{cite web|url=http://etymonline.com/?term=giraffe|title= Giraffe|publisher= Online Etymology Dictionary|accessdate= 2011-11-01}}</ref> The modern English form developed around 1600 from the [[French language|French]] ''girafe''.<ref name=OED/> The species name ''camelopardalis'' is a [[Latin]] word.<ref>{{Cite web|url=http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0059%3Aentry%3Dcamelopardalis|title= camelopardalis|publisher= A Latin Dictionary, Perseus Digital Library|accessdate= 2011-11-23}}</ref>
''Kameelperd'' is also the name for the species in [[Afrikaans]].<ref name=walker>{{cite book|author=Walker, C.|year=1997|title=Signs of the Wild|publisher=Struik|page=142|isbn=1-86825-896-3}}</ref> Other African names for the giraffe include ''Ekorii'' ([[Teso language|Ateso]]), ''Kanyiet'' ([[Elgon languages|Elgon]]), ''Nduida'' ([[Gikuyu language|Gikuyu]]), ''Tiga'' ([[Nandi–Markweta languages|Kalenjin]] and [[Luo language|Luo]]), ''Ndwiya'' ([[Kamba language|Kamba]]), ''Nudululu'' ([[Hehe language|Kihehe]]), ''Ntegha'' ([[Turu language|Kinyaturu]]), ''Ondere'' ([[Lugbara language|Lugbara]]), ''Etiika'' ([[Luhya language|Luhya]]), ''Kuri'' ([[Ma'di language|Ma'di]]), ''Oloodo-kirragata'' or ''Olchangito-oodo'' ([[Maasai language|Maasai]]), ''Lenywa'' ([[Meru language|Meru]]), ''Hori'' ([[Pare language|Pare]]), ''Lment'' ([[Samburu language|Samburu]]) and ''Twiga'' ([[Swahili language|Swahili]] and others) in the east;<ref name=Kingdon1988/>{{rp|313}} and ''Tutwa'' ([[Lozi language|Lozi]]), ''Nthutlwa'' ([[Tsonga language|Shangaan]]), ''Indlulamitsi'' ([[Swazi language|Siswati]]), ''Thutlwa'' ([[Tswana language|Sotho]]), ''Thuda'' ([[Venda language|Venda]]) and ''Ndlulamithi'' ([[Zulu language|Zulu]]) in the south.<ref name=walker/>
==Taxonomy and evolution==
[[File:Shansitherium tafeli Beijing.jpg|thumb|left|Mounted ''[[Shansitherium]]'' skeleton from the [[Beijing Museum of Natural History]]]]
The giraffe is one of only two living species of the family [[Giraffidae]], the other being the [[okapi]]. The family was once much more extensive, with over 10 fossil [[Genus|genera]] described. Giraffids first arose 8 million years ago (mya) in south-central Europe during the [[Miocene]] epoch. The superfamily [[Giraffoidea]], together with the family [[Antilocapridae]] (whose only extant species is the [[pronghorn]]), evolved from the extinct family [[Palaeomerycidae]].<ref name="Mitchell20003">{{cite journal | author = Mitchell, G.; Skinner, J. D. | year = 2003 | title = On the origin, evolution and phylogeny of giraffes ''Giraffa camelopardalis'' | journal = Transactions of the Royal Society of South Africa | volume = 58 | issue = 1| pages = 51–73| doi = 10.1080/00359190309519935| url = http://www.bringyou.to/GiraffeEvolution.pdf}}</ref> The earliest known giraffid was the deer-like ''[[Climacoceras]]''.
While the progressive elongation of the neck and limbs can be found throughout the giraffid lineage, it became more pronounced in genera such as ''[[Giraffokeryx]]'', ''[[Palaeotragus]]'' (possible ancestor of the okapi), ''[[Samotherium]]'' and ''[[Bohlinia]]''.<ref name="Mitchell20003"/> ''Bohlinia'' entered China and northern India in response to climate change. From here, the genus ''[[Giraffa]]'' evolved and, around 7 mya, entered Africa. Further climate changes caused the extinction of the Asian giraffes, while the African ones survived and radiated into several new species. ''G. camelopardalis'' arose around 1 mya in eastern Africa during the [[Pleistocene]].<ref name="Mitchell20003"/> Some biologists suggest that the modern giraffe descended from ''[[Giraffa jumae|G. jumae]]'';<ref name=sim1996/> others find ''[[Giraffa gracilis|G. gracilis]]'' a more likely candidate.<ref name="Mitchell20003"/> It is believed that the main driver for the evolution of the giraffes was the change from extensive forests to more open habitats, which began 8 mya.<ref name="Mitchell20003"/> Some researchers have hypothesized that this new habitat with a different diet, including ''[[Acacia]]'', may have exposed giraffe ancestors to toxins that caused higher mutation rates and a higher rate of evolution.<ref name="bada"/>
The giraffe was one of the many species first described by [[Carl Linnaeus]] in 1758. He gave it the binomial name ''[[Cervus]] camelopardalis''. [[Morten Thrane Brünnich]] classified the genus ''Giraffa'' in 1772.<ref name="Dagg1971"/> In the early 19th century, [[Jean-Baptiste Lamarck]] believed that the giraffe's long neck was an "acquired characteristic", developed as generations of ancestral giraffes strived to reach the leaves of tall trees.<ref name="Prothero 2003"/> This theory was eventually rejected, and scientists now believe that the giraffe's neck arose through Darwinian [[natural selection]]—that ancestral giraffes with long necks thereby had a competitive advantage that better enabled them to reproduce and pass on their genes.<ref name="Prothero 2003"/>
===
[[File:Genetic subdivision in the giraffe based on mitochondrial DNA sequences.png|thumb|400px|right|"Approximate geographic ranges, fur patterns and [[phylogenetics|phylogenetic]] relationships between some giraffe subspecies based on [[mitochondrial DNA]] sequences. Colored dots on the map represent sampling localities. The phylogenetic tree is a [[maximum-likelihood]] [[Phylogenetic tree#Special tree types|phylogram]] based on samples from 266 giraffes. Asterisks along branches correspond to [[Clade#Definitions|node]] values of more than 90 percent [[Resampling (statistics)|bootstrap]] support. Stars at branch tips identify [[paraphyletic]] [[haplotype]]s found in Maasai and Reticulated giraffes".<ref name=GeneticStructure>{{cite journal|title=Extensive population genetic structure in the giraffe|author=Brown, D. M.; Brenneman R. A.; Koepfli, K-P.; Pollinger, J. P.; Milá, B.; Georgiadis, N. J.; Louis Jr., E. E.; Grether, G. F.; Jacobs, D. K.; Wayne R. K.|journal= BMC Biology |year=2007|volume=5|issue=1|page=57|doi=10.1186/1741-7007-5-57|pmc=2254591|pmid=18154651}}</ref>]]
Up to nine subspecies of giraffe are recognized (with population estimates {{As of|2010|lc=y}}):
* ''[[Nubian giraffe|G. c. camelopardalis]]'',<ref name= "MacDonald">{{Cite book|author=Pellow, R. A.|contribution=Giraffe and Okapi|year=2001|title=The Encyclopedia of Mammals|edition= 2nd|editor=MacDonald, D|publisher=Oxford University Press|pages=520–27|isbn=0-7607-1969-1}}</ref> the [[nominate subspecies]], is known as the [[Nubia]]n giraffe. It is found in eastern [[South Sudan]] and south-western [[Ethiopia]]. Fewer than 250 are thought to remain in the wild, although this number is uncertain.<ref name=wildstatus>{{Cite web|url= http://www.giraffeconservation.org/giraffe_facts.php?pgid=40 |title= Giraffe – The Facts: Current giraffe status? |publisher=Giraffe Conservation Foundation |accessdate= 2010-12-21}}</ref> It is rare in captivity, although a group is kept at [[Al Ain Zoo]] in the [[United Arab Emirates]].<ref name='"Al Ain exhibits"'>{{cite web|title=Exhibits|url=http://www.awpr.ae/en/Visit/Pages/AfricanMixedExhibit.aspx|publisher=Al Ain Zoo|date=2003-02-25|accessdate= 2011-11-21}}</ref> In 2003, this group numbered 14.<ref>{{Cite web|url=http://www.uaeinteract.com/docs/Nubian_giraffe_born_in_Al_Ain_zoo/6971.htm|title=Nubian giraffe born in Al Ain zoo|publisher=UAE Interact|accessdate=2010-12-21}}</ref>
* ''[[Reticulated giraffe|G. c. reticulata]]'',<ref name= "MacDonald"/> known as the reticulated<ref name= "MacDonald"/> or [[Horn of Africa|Somali]] giraffe, is native to north-eastern [[Kenya]], southern Ethiopia and [[Somalia]]. It is estimated that no more than 5,000 remain in the wild,<ref name=wildstatus/> and based on [[International Species Information System]] records, more than 450 are kept in zoos.<ref name=ISIS>{{cite web|url=https://app.isis.org/abstracts/Abs77545.asp|title= Giraffa |publisher=[[International Species Information System|ISIS]]|year=2010|accessdate= 2010-11-04}}</ref>
* ''[[Angolan giraffe|G. c. angolensis]]'', the [[Angola]]n or [[Namibia]]n giraffe, is found in northern Namibia, south-western [[Zambia]], [[Botswana]] and western [[Zimbabwe]]. A 2009 genetic study on this subspecies suggests that the northern [[Namib Desert]] and [[Etosha National Park]] populations form a separate subspecies.<ref>{{cite journal|doi= 10.1111/j.1365-2028.2009.01078.x|author= Brenneman, R. A.; Louis, E. E. Jr; Fennessy, J. |year=2009|title=Genetic structure of two populations of the Namibian giraffe, ''Giraffa camelopardalis angolensis''|journal=African Journal of Ecology|volume=47|issue=4|pages=720–28}}</ref> It is estimated that no more than 20,000 remain in the wild;<ref name=wildstatus/> and approximately 20 are kept in zoos.<ref name=ISIS/>
* ''[[Kordofan giraffe|G. c. antiquorum]]'',<ref name= "MacDonald"/> the [[Kordofan]] giraffe, has a distribution which includes southern [[Chad]], the [[Central African Republic]], northern [[Cameroon]] and north-eastern [[Democratic Republic of the Congo|DR Congo]]. Populations in Cameroon were formerly included in ''G. c. peralta'', but this was incorrect.<ref name=WestAfricaGiraffe>{{Cite journal|author=Hassanin, A.; Ropiquet, A.; Gourmand, B-L.; Chardonnet, B.; Rigoulet, J.|year=2007|title= Mitochondrial DNA variability in Giraffa camelopardalis: consequences for taxonomy, phylogeography and conservation of giraffes in West and central Africa|journal=Comptes Rendus Biologies|volume=330|issue=3|pages= 173–83|pmid= 17434121|doi=10.1016/j.crvi.2007.02.008}}</ref> No more than 3,000 are believed to remain in the wild.<ref name=wildstatus/> Considerable confusion has existed over the status of this subspecies and ''G. c. peralta'' in zoos. In 2007 it was shown that all alleged ''G. c. peralta'' in [[List of zoos#Europe|European zoos]] were, in fact, ''G. c. antiquorum''.<ref name=WestAfricaGiraffe/> With this correction approximately 65 are kept in zoos.<ref name=ISIS/>
* ''[[Masai giraffe|G. c. tippelskirchi]]'',<ref name= "MacDonald"/> known as the [[Maasai people|Masai]]<ref name= "MacDonald"/> or [[Kilimanjaro]] giraffe, can be found in central and southern Kenya and in [[Tanzania]]. It is estimated that no more than 40,000 remain in the wild,<ref name=wildstatus/> and approximately 100 are kept in zoos.<ref name=ISIS/>
* ''[[Rothschild giraffe|G. c. rothschildi]]''<ref name= "MacDonald"/> is known variously as the [[Walter Rothschild, 2nd Baron Rothschild|Rothschild]],<ref name= "MacDonald"/> [[Lake Baringo|Baringo]] or [[Uganda]]n giraffe. Its range includes parts of Uganda and Kenya.<ref name=iucn/> Its presence in South Sudan is uncertain.<ref name=IUCNrothschildi>{{IUCN2008|assessors=Fennessy, J.; Brown, D.|year=2008|id=174469|title=Giraffa camelopardalis ssp. rothschildi|downloaded=2009-3-13}}</ref> Fewer than 700 are believed to remain in the wild,<ref name=wildstatus/> and more than 450 are kept in zoos.<ref name=ISIS/>
* ''[[South African giraffe|G. c. giraffa]]'', the [[South Africa]]n giraffe, is found in northern South Africa, southern Botswana, southern Zimbabwe and south-western [[Mozambique]]. It is estimated that no more than 12,000 remain in the wild,<ref name=wildstatus/> and approximately 45 are kept in zoos.<ref name=ISIS/>
* ''[[Rhodesian giraffe|G. c. thornicrofti]]'',<ref name= "MacDonald"/> called the [[Harry Scott Thornicroft|Thornicroft]]<ref name= "MacDonald"/> or [[Rhodesia]]n giraffe, is restricted to the [[Luangwa River|Luangwa Valley]] in eastern Zambia. No more than 1,500 remain in the wild,<ref name=wildstatus/> with none kept in zoos.<ref name=ISIS/>
* ''[[West African giraffe|G. c. peralta]]'',<ref name= "MacDonald"/> commonly known as the West African,<ref name= "MacDonald"/> [[Niger]] or [[Nigeria]]n giraffe,<ref name=IUCNperalta>{{IUCN2008|assessors=Fennessy, J.; Brown, D.|year=2008|id=136913|title=Giraffa camelopardalis ssp. peralta|downloaded=2012-03-05}}</ref> is [[Endemism|endemic]] to south-western Niger.<ref name=iucn/> Fewer than 220 individuals remain in the wild.<ref name=wildstatus/> Giraffes in Cameroon were formerly believed to belong to this subspecies, but are actually ''G. c. antiquorum''.<ref name=WestAfricaGiraffe/> This error resulted in some confusion over its status in zoos, but in 2007 it was established that all "''G. c. peralta''" kept in European zoos actually are ''G. c. antiquorum''.<ref name=WestAfricaGiraffe/>
[[File:Giraffe koure niger 2006.jpg|thumb|The endangered West African giraffe]]
Giraffe subspecies are distinguished by their coat patterns. The reticulated and Masai giraffe represent two extremes of giraffe patch shapes. The former has neatly shaped patches while the latter has jagged ones.<ref name=estes/> There are also differences in the width of the lines separating the patches. The West African giraffe has thick lines while the Nubian and reticulated giraffe have thin ones.<ref name=Kingdon1988/>{{rp|321–22}} The former also has a lighter coat pelage than other subspecies.<ref name=Kingdon1988/>{{rp|322}}
A 2007 study on the genetics of six subspecies—the West African, Rothschild, reticulated, Masai, Angolan and South African giraffe—suggests that they may in fact be separate species. The study deduced from [[genetic drift]] in [[nuclear DNA|nuclear]] and [[mitochondrial DNA]] (mtDNA) that giraffes from these populations are [[Reproductive isolation|reproductively isolated]] and rarely interbreed, even though no natural obstacles block their mutual access.<ref name=GeneticStructure/> This includes adjacent populations of Rothschild, reticulated and Masai giraffes. The Masai giraffe may also consist of a few species separated by the [[East African Rift|Rift Valley]]. Reticulated and Masai giraffes have the highest mtDNA diversity, which is consistent with the fact that giraffes originated in eastern Africa. Populations further north evolved from the former while those to the south evolved from the latter. Giraffes appear to select mates of the same coat type, which are imprinted on them as calves.<ref name=GeneticStructure/> The implications of these findings for the conservation of giraffes were summarised by David Brown, lead author of the study, who told [[BBC News]]: "Lumping all giraffes into one species obscures the reality that some kinds of giraffe are on the brink. Some of these populations number only a few hundred individuals and need immediate protection."<ref>{{Cite news|publisher=BBC News|title=Not one but 'six giraffe species'|author= Lever, A-M.|date=2007-12-21|url=http://news.bbc.co.uk/1/hi/sci/tech/7156146.stm |accessdate=2009-03-04}}</ref>
The West African giraffe is more closely related to the Rothchild and reticulated giraffe than to the Kordofan giraffe. Its ancestor may have migrated from eastern to northern Africa and then to its current range with the development of the Sahara desert. At its largest, [[Lake Chad]] may have acted as a barrier between West African and Kordofan giraffes during the [[Holocene]].<ref name=WestAfricaGiraffe/>
==
{{commons cat|Category:Giraffa camelopardalis anatomy}}
[[File:Giraffe08 - melbourne zoo.jpg|thumb|thumb|Closeup of the head of a giraffe at the [[Melbourne Zoo]]]]
[[File:
Fully grown giraffes stand {{convert|5|–|6|m|abbr=on}} tall, with males taller than females.<ref name="Dagg1971">{{Cite journal|author=Dagg, A. I.|year=1971|title=Giraffa camelopardalis|journal= Mammalian Species|volume=5|pages=1–8|url= http://www.science.smith.edu/msi/pdf/i0076-3519-005-01-0001.pdf|doi=10.2307/3503830|issue=5}}</ref> The average weight is {{convert|1600|kg|lb|abbr=on}} for an adult male and {{convert|830|kg|lb|abbr=on}} for an adult female.<ref name="Skinner1990">{{Cite book|author=Skinner, J. D.; Smithers, R. H. M.|year=1990|title=The mammals of the southern African subregion|pages=616–20|publisher=University of Pretoria|isbn=0-521-84418-5}}</ref> Despite its long neck and legs, the giraffe's body is relatively short.<ref name=anatomy/>{{rp|66}} Located at both sides of the head, the giraffe's large, bulging eyes give it good all-round vision from its great height.<ref name=Williams/>{{rp|25}} Giraffes see in color<ref name=Williams/>{{rp|26}} and their senses of hearing and [[olfaction|smell]] are also sharp.<ref name="Prothero 2003"/> The animal can close its muscular nostrils to protect against sandstorms and ants.<ref name=Williams/>{{rp|27}} The giraffe's [[prehensile]] tongue is about {{convert|50|cm|in|abbr=on}} long. It is purplish-black in color, perhaps to protect against sunburn, and is useful for grasping foliage as well as for grooming and cleaning the animal's nose.<ref name=Williams/>{{rp|27}} The upper lip of the giraffe is also prehensile and useful when foraging. The lips, tongue and inside of the mouth are covered in [[Taste bud|papillae]] to protect against thorns.<ref name="Dagg1971"/>
[[File:Giraffa camelopardalis reticulata-atTobuZoo-2012.ogv|thumb|(video) A pair of giraffes at [[Tobu Zoo]], in [[Saitama prefecture|Saitama]], Japan.]]
The coat has dark blotches or patches (which can be orange, [[Chestnut (color)|chestnut]], brown or nearly black on color<ref name="Prothero 2003"/>) separated by light hair (usually white or [[Cream (colour)|cream]] in color<ref name="Prothero 2003"/>). Male giraffes become darker as they age.<ref name=estes>{{Cite book|title=The Behavior Guide to African Mammals: including Hoofed Mammals, Carnivores, Primates|author=Estes, R.|publisher=University of California Press|pages=202–07|year=1992|isbn=0-520-08085-8}}</ref> The coat pattern serves as [[camouflage]], allowing it to blend in the light and shade patterns of savanna woodlands.<ref name="Mitchell20003"/><ref name= "MacDonald"/> The skin underneath the dark areas may serve as windows for [[thermoregulation]], being sites for complex blood vessel systems and large sweat glands.<ref name=Mitchell2004>{{Cite journal|author=Mitchell, G.; Skinner, J.D.|year=2004|title=Giraffe thermoregulation: a review|journal=Transactions of the Royal Society of South Africa: Proceedings of a Colloquium on Adaptations in Desert Fauna and Flora|volume=59|issue=2|pages=49–57|issn=0035-919X|url=http://www.sabinet.co.za/abstracts/royalsa/royalsa_v59_n2_a13.html|doi=10.1080/00359190409519170}}</ref> Each individual giraffe has a unique coat pattern.<ref name=estes/> The skin of a giraffe is mostly gray.<ref name="Skinner1990"/> It is also thick and allows them to run through thorn bush without being punctured.<ref name=Williams/>{{rp|34}} Their fur may serve as a chemical defence, as it is full of parasite repellents that give the animal a characteristic scent. There are at least eleven main [[aromaticity|aromatic]] chemicals in the fur, although [[indole]] and [[3-methylindole]] are responsible for most of the smell. Because the males have a stronger odor than the females, it is suspected that it also has a sexual function.<ref>{{Cite journal|author=Wood, W. F.; Weldon, P. J.|year=2002|title=The scent of the reticulated giraffe (''Giraffa camelopardalis reticulata'')|journal=Biochemical Systematics and Ecology|volume=30|issue=10|pages=913–17|doi=10.1016/S0305-1978(02)00037-6}}</ref> Along the animal's neck is a mane made of short, erect hairs.<ref name="Dagg1971"/> The {{convert|1|m|ft|abbr=on}} tail ends in a long, dark tuft of hair and is used as a defense against insects.<ref name=Williams/>{{rp|36}}
===Skull and ossicones===
Both sexes have prominent horn-like structures called [[ossicone]]s, which are formed from ossified [[cartilage]], covered in skin and fused to the skull at the [[parietal bone]]s.<ref name=estes/> Being [[vascular]]ized, the ossicones may have a role in thermoregulation.<ref name=Mitchell2004/> Ossicones are also used in combat between males.<ref name="sim2010"/> Appearance is a reliable guide to the sex or age of a giraffe: the ossicones of females and young are thin and display tufts of hair on top, whereas those of adult males end in knobs and tend to be bald on top.<ref name=estes/> There is also a median lump, which is more prominent in males, at the front of the [[skull]].<ref name="Dagg1971"/> Males develop [[calcium]] deposits that form bumps on their skulls as they age.<ref name="Prothero 2003"/> A giraffe's skull is lightened by multiple [[Sinus (anatomy)|sinuses]].<ref name=anatomy/>{{rp|70}} However, as males age, their skulls become heavier and more club-like, helping them become more dominant in combat.<ref name=estes/> The upper jaw has a grooved [[palate]] and lacks front teeth.<ref name=Williams/>{{rp|26}} The giraffe's [[Molar (tooth)|molar]]s have a rougher surface than those of some other mammals.<ref name=Williams/>{{rp|27}}
===Legs, locomotion and posture===
The front and back legs of a giraffe are approximately the same length. The [[Radius (bone)|radius]] and [[ulna]] of the front legs are articulated by the [[carpus]], which, while structurally equivalent to the human wrist, functions as a knee.<ref>{{cite book|author=MacClintock, D.; Mochi, U.|year=1973|title=A natural history of giraffes|publisher=Scribner|page=30|isbn=0-684-13239-7}}</ref> The foot of the giraffe reaches a diameter of {{convert|30|cm|in|abbr=on}}, and the [[hoof]] is {{convert|15|cm|in|abbr=on}} high in males and {{convert|10|cm|in|abbr=on}} in females.<ref name=Williams/>{{rp|36}} The rear of each hoof is low and the [[fetlock]] is close to the ground, allowing the foot to support the animal's weight.<ref name="Dagg1971"/> Giraffes lack [[dewclaw]]s and interdigital glands. The giraffe's pelvis, though relatively short, has an [[Ilium (bone)|ilium]] that is outspread at the upper ends.<ref name="Dagg1971"/>
A giraffe has only two [[gait]]s: walking and galloping. Walking is done by moving the legs on one side of the body at the same time, then doing the same on the other side.<ref name=estes/> When galloping, the hind legs move around the front legs before the latter move forward,<ref name="Prothero 2003"/> and the tail will curl up.<ref name=estes/> The animal relies on the forward and backward motions of its head and neck to maintain balance and the counter momentum while galloping.<ref name=Kingdon1988/>{{rp|327–29}} The giraffe can reach a sprint speed of up to {{convert|60|km/h|abbr=on}},<ref>{{Cite journal| last = Garland | first = T | coauthors = Janis, C. M. | year = 1993 | title = Does metatarsal/femur ratio predict maximal running speed in cursorial mammals? | url = http://www.biology.ucr.edu/people/faculty/Garland/GarlandJanis1993.pdf | journal = Journal of Zoology | volume = 229 | issue = 1 | pages = 133–51 | doi = 10.1111/j.1469-7998.1993.tb02626.x }}</ref> and can sustain {{convert|50|km/h|abbr=on}} for several kilometers.<ref>{{Cite book|author=Rafferty, John. P|year=2011|title=Grazers (Britannica Guide to Predators and Prey)|publisher=Britannica Educational Publishing|page=194|isbn=1-61530-336-7|postscript=<!-- Bot inserted parameter. Either remove it; or change its value to "." for the cite to end in a ".", as necessary. -->{{inconsistent citations}}}}</ref>
A giraffe rests by lying with its body on top of its folded legs.<ref name=Kingdon1988>{{Cite book|author=Kingdon, J. |year=1988|title=East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part B: Large Mammals|pages=313–37|publisher=University Of Chicago Press |isbn=0-226-43722-1}}</ref>{{rp|329}} To lie down, the animal kneels on its front legs and then lowers the rest of its body. To get back up, it first gets on its knees and spreads its hind legs to raise its hindquarters. It then straightens its front legs. With each step, the animal swings its head.<ref name=Williams/>{{rp|31}} The giraffe sleeps intermittently around 4.6 hours per day, mostly at night.<ref name=sleep/> It usually sleeps lying down, however, standing sleeps have been recorded, particularly in older individuals. Intermittent short "deep sleep" phases while lying are characterized by the giraffe bending its neck backwards and resting its head on the hip or thigh, a position believed to indicate [[paradoxical sleep]].<ref name=sleep>{{cite journal|last=Tobler, I.; Schwierin, B.|title=Behavioural sleep in the giraffe (''Giraffa camelopardalis'') in a zoological garden|year=1996|journal=Journal of Sleep Research|volume=5|issue=1|pages=21–32|doi=10.1046/j.1365-2869.1996.00010.x|first1=I.|last2=Schwierin|first2=B.|pmid=8795798}}</ref> If the giraffe wants to bend down to drink, it either spreads its front legs or bends its knees.<ref name=estes/> Giraffes would probably not be competent swimmers as their long legs would be highly cumbersome in the water,<ref name = "swim">{{cite journal | doi = 10.1016/j.jtbi.2010.04.007 | author = Henderson, D. M.; Naish, D. | year = 2010 | title = Predicting the buoyancy, equilibrium and potential swimming ability of giraffes by computational analysis | url = | journal = Journal of Theoretical Biology | volume = 265 | issue = 2| pages = 151–59 | pmid = 20385144 }}</ref> although they could possibly float.<ref name="Naish">{{Cite magazine| last = Naish | first = D. | author-link = Darren Naish |date= January 2011 | year = 2011| title = Will it Float? | periodical = [[Scientific American]] | issn = 0036-8733 | volume = 304 | issue = 1 | page = 22| url = http://www.scientificamerican.com/article.cfm?id=will-it-float}}</ref> When swimming, the thorax would be weighed down by the front legs, making it difficult for the animal to move its neck and legs in harmony<ref name = "swim"/><ref name="Naish"/> or keep its head above the surface.<ref name = "swim"/>
==
[[File:Flickr - Rainbirder - High-rise living.jpg|thumb|left|An adult male giraffe feeding high up on an acacia]]
The giraffe has an extremely elongated neck, which can be up to {{convert|2|m|abbr=on}} in length, accounting for much of the animal's vertical height.<ref name=Williams/>{{rp|29}} The long neck results from a disproportionate lengthening of the [[cervical vertebrae]], not from the addition of more vertebrae. Each cervical vertebra is over {{convert|28|cm|in|abbr=on}} long.<ref name=anatomy>{{cite book|author=Swaby, S.|year=2010|contribution=Giraffe|editor=Harris, T.|title=Mammal Anatomy: An Illustrated Guide|publisher=Marshall Cavendish Corporation|pages=64–84|isbn=0-7614-7882-5}}</ref>{{rp|71}} They comprise 52–54 percent of the length of the giraffe's [[vertebral column]], compared with the 27–33 percent typical of similar large ungulates, including the giraffe’s closest living relative, the [[okapi]].<ref name=bada>{{Cite journal | doi = 10.1111/j.1096-3642.2008.00458.x | last = Badlangana | first = L. N. | coauthors = Adams, J. W.; Manger P. R. | title = The giraffe ''(Giraffa camelopardalis)'' cervical vertebral column: A heuristic example in understanding evolutionary processes? | journal = Zoological Journal of the Linnean Society | volume = 155 | issue = 3 | pages = 736–57 | year = 2009}}</ref> This elongation largely takes place after birth, as giraffe mothers would have a difficult time giving birth to young with the same neck proportions as adults.<ref name=van>{{Cite journal | doi = 10.1002/jez.b.21353 | last = Van Sittert | first = S. J. | coauthors = Skinner, J. D.; Mitchell, G. | title = From fetus to adult – An allometric analysis of the giraffe vertebral column | journal = Journal of Experimental Zoology Part B Molecular and Developmental Evolution | volume = 314B | issue = 6 | pages = 469–79 | year = 2010}}</ref> The giraffe's head and neck are held up by large muscles and a [[nuchal ligament]], which are anchored by long dorsal spines on the anterior [[thoracic vertebrae]], giving the animal a hump.<ref name="Dagg1971"/>
The giraffe's neck vertebrae have [[ball and socket joint]]s.<ref name=anatomy/>{{rp|71}} In particular, the [[Atlas (anatomy)|atlas]]–[[Axis (anatomy)|axis]] joint (C1 and C2) allows the animal to tilt its head vertically and reach more branches with the tongue.<ref name=Williams/>{{rp|29}} The point of articulation between the cervical and thoracic vertebrae of giraffes is shifted to lie between the first and second thoracic vertebrae (T1 and T2), unlike most other ruminants where the articulation is between the seventh cervical vertebra (C7) and T1.<ref name=bada/><ref name=van/> This allows C7 to contribute directly to increased neck length and has given rise to the suggestion that T1 is actually C8, and that giraffes have added an extra cervical vertebra.<ref>{{Cite journal|author=Solounias, N.|year=1999|title=The remarkable anatomy of the giraffe's neck|journal=Journal of Zoology|volume=247|issue=2|pages=257–68|doi=10.1111/j.1469-7998.1999.tb00989.x|url=http://www.ikhebeenvraag.be/mediastorage/FSDocument/73/download.pdf}}</ref> However, this proposition is not generally accepted, as T1 has other morphological features, such as an articulating [[rib]], deemed diagnostic of thoracic vertebrae, and because exceptions to the mammalian limit of seven cervical vertebrae are generally characterized by increased [[neurological disorder|neurological anomalies]] and maladies.<ref name=bada/>
There are two main hypotheses regarding the evolutionary origin and maintenance of elongation in giraffe necks.<ref name=sim2010>{{Cite journal | doi = 10.1111/j.1469-7998.2010.00711.x | last = Simmons | first = R. E.| coauthors = Altwegg, R. | title = Necks-for-sex or competing browsers? A critique of ideas on the evolution of giraffe | journal = Journal of Zoology | volume = 282 | issue = 1 | pages = 6–12 | year = 2010}}</ref> The "competing [[browsing (predation)|browsers]] hypothesis" was originally suggested by [[Charles Darwin]] and only challenged recently. It suggests that competitive pressure from smaller browsers, such as [[kudu]], [[steenbok]] and [[impala]], encouraged the elongation of the neck, as it enabled giraffes to reach food that competitors could not. This advantage is real, as giraffes can and do feed up to {{convert|4.5|m|abbr=on}} high, while even quite large competitors, such as kudu, can only feed up to about {{convert|2|m|abbr=on}} high.<ref name=dt1990>{{Cite journal | doi = 10.1111/j.1365-2028.1990.tb01136.x | last = du Toit | first = J. T. | title = Feeding-height stratification among African browsing ruminants | journal = African Journal of Ecology | volume = 28 | issue = 1 | pages = 55–62 | year = 1990 | url = http://courses.biology.utah.edu/goller/7406/Goller7406/duToitPdfs/Feedingheightstrat_1990.pdf}}</ref> There is also research suggesting that browsing competition is intense at lower levels, and giraffes feed more efficiently (gaining more leaf biomass with each mouthful) high in the canopy.<ref>{{Cite journal|author= Cameron, E. Z.; du Toit, J. T. | title = Winning by a Neck: Tall Giraffes Avoid Competing with Shorter Browsers| journal = American Naturalist | volume = 169| issue = 1| pages = 130–35| year = 2007| doi = 10.1086/509940 |pmid= 17206591 |url= http://www.cnr.usu.edu/files/uploads/faculty/winning_by_a_neck-du_Toit.pdf}}</ref><ref>{{Cite journal|author= Woolnough, A. P.; du Toit, J. T. | title = Vertical zonation of browse quality in tree canopies exposed to a size-structured guild of African browsing ungulates| journal = Oecologia | volume = 129| issue = 1| pages = 585–90| year = 2001| doi = 10.1007/s004420100771|url=http://courses.biology.utah.edu/goller/7406/Goller7406/duToitPdfs/Verticalzonation_2001.pdf}}</ref> However, scientists disagree about just how much time giraffes spend feeding at levels beyond the reach of other browsers,<ref name=sim1996/><ref name=sim2010/><ref name=dt1990/><ref name=sexdiff>{{Cite journal|doi= 10.1111/j.1439-0310.1991.tb01190.x |author= Young, T. P.; Isbell, L. A. | title = Sex differences in giraffe feeding ecology: energetic and social constraints| journal = Ethology | volume = 87| issue = 1–2| pages = 79–89| year = 1991 |dio = 10.1007/s004420100771|url=http://tpyoung.ucdavis.edu/publications/1991GiraffesEthology.pdf}}</ref>
and a 2010 study found that adult giraffes with longer necks actually suffered higher mortality rates under drought conditions than their shorter-necked counterparts. This study suggests that maintaining a longer neck requires more nutrients, which puts longer-necked giraffes at risk during a food shortage.<ref name="demography">{{cite journal|author=Mitchell, G.; van Sittert, S.; Skinner, J. D.|year=2010|title=The demography of giraffe deaths in a drought|journal=Transactions of the Royal Society of South Africa|volume=65|issue=
3|pages=165–68|doi=10.1080/0035919X.2010.509153}}</ref>
The other main theory, the [[sexual selection]] hypothesis, proposes that the long necks evolved as a secondary [[sexual dimorphism|sexual characteristic]], giving males an advantage in "necking" contests (see below) to establish dominance and obtain access to sexually receptive females.<ref name=sim1996>{{Cite journal|author=Simmons, R. E.; Scheepers, L. | title = Winning by a Neck: Sexual Selection in the Evolution of Giraffe| journal = The American Naturalist| volume = 148| issue = 5| pages = 771–86| year = 1996|url=http://bill.srnr.arizona.edu/classes/182/Giraffe/WinningByANeck.pdf|doi=10.1086/285955}}</ref> In support of this theory, necks are longer and heavier for males than females of the same age,<ref name=sim1996/><ref name=sim2010/> and the former do not employ other forms of combat.<ref name=sim1996/> However, one objection is that it fails to explain why female giraffes also have long necks.<ref>{{Cite journal|author= Mitchell, G.; van Sittert, S. J.; Skinner, J. D. | title = Sexual selection is not the origin of long necks in giraffes| journal = Journal of Zoology | volume = 278| issue = 4| pages = 281–86| year = 2009| doi=10.1111/j.1469-7998.2009.00573.x}}</ref>
{{-}}
==
[[File:Flickr - Rainbirder - Reticulated Giraffe drinking.jpg|thumb|Giraffe bending down to drink. The animal's rete mirabile prevents excess blood flow to the brain when the neck is lowered.]]
In mammals, the left [[recurrent laryngeal nerve]] is longer than the right; in the giraffe it is over {{convert|30|cm|in|abbr=on}} longer. These nerves are longer in the giraffe than in any other living animal;<ref name="Wedel">{{Cite journal|author=Wedel, M. J.|year=2012|title=A monument of inefficiency: the presumed course of the recurrent laryngeal nerve in sauropod dinosaurs|journal=Acta Palaeontologica Polonica|volume=57|issue=2|pages=251–56|doi=10.4202/app.2011.0019|url=http://www.app.pan.pl/archive/published/app57/app20110019.pdf}}</ref> the left nerve is over {{convert|2|m|abbr=on}} long.<ref>{{cite book|author=Harrison, D. F. N.|year=1995|title=The Anatomy and Physiology of the Mammalian Larynx|publisher=Cambridge University Press|page=165|isbn=0-521-45321-6}}</ref> Each nerve cell in this path begins in the [[brainstem]] and passes down the neck along the [[vagus nerve]], then branches off into the recurrent laryngeal nerve which passes back up the neck to the larynx. Thus, these nerve cells have a length of nearly {{convert|5|m|abbr=on}} in the largest giraffes.<ref name="Wedel"/> The structure of a giraffe's brain resembles that of domestic cattle.<ref name=Williams/>{{rp|31}} The shape of the skeleton gives the giraffe a small lung volume relative to its mass.<ref name=SkinnerJD2011>{{Cite journal|author=Skinner, J. D.; Mitchell, G.|year= 2011|title= Lung volumes in giraffes, ''Giraffa camelopardalis''|journal= Comparative Biochemistry and Physiology – Part A: Molecular & Integrative Physiology|volume= 158|issue= 1|pages= 72–78|doi= 10.1016/j.cbpa.2010.09.003|url= http://137.215.9.22/bitstream/handle/2263/16472/Mitchell_Lung(2011).PDF?sequence=1}}</ref> Its long neck gives it a large amount of [[Dead space (physiology)|dead space]], in spite of its narrow windpipe. These factors increase the resistance to airflow. Nevertheless, the animal can still supply enough oxygen to its tissues.<ref name=SkinnerJD2011/>
The [[circulatory system]] of the giraffe has several adaptations for its great height. Its heart, which can weigh more than {{convert|25|lb|kg|abbr=on}} and measures about {{convert|2|ft|cm|abbr=on}} long, must generate approximately double the blood pressure required for a human to maintain blood flow to the brain.<ref name="Prothero 2003"/> Giraffes have unusually high heart rates for their size, at 150 beats per minute.<ref name=anatomy/>{{rp|76}} In the upper neck, the [[rete mirabile]] prevents excess blood flow to the brain when the giraffe lowers its head.<ref name= "MacDonald"/> The [[jugular vein]]s also contain several (most commonly seven) valves to prevent blood flowing back into the head from the [[inferior vena cava]] and [[right atrium]] while the head is lowered.<ref>{{cite journal|doi=10.3957/056.039.0210|author=Mitchell, G.; van Sittert, S. J.; Skinner, J. D.|title=The structure and function of giraffe jugular vein valves|journal= South African Journal of Wildlife Research|volume=39|issue=2|pages=175–80|url=http://137.215.9.22/bitstream/handle/2263/13994/Mitchell_Structure(2009).pdf?sequence=1 |year=2009}}</ref> Conversely, the blood vessels in the lower legs are under great pressure (because of the weight of fluid pressing down on them). To solve this problem, the skin of the lower legs is thick and tight; preventing too much blood from pouring into them.<ref name= "MacDonald"/>
Giraffes have [[Esophagus|oesophageal muscles]] that are unusually strong to allow regurgitation of food from the stomach up the neck and into the mouth for [[wikt:ruminate|rumination]].<ref name=anatomy/>{{rp|78}} They have four chambered stomachs, as in all ruminants, and the first chamber has adapted to their specialized diet.<ref name="Dagg1971"/> The giraffe's intestines measure up to {{convert|80|m|ft|abbr=on}} in length<ref name="Dagg1971"/> and have a relatively small ratio of small to large intestine.<ref>{{cite journal | author = Pérez, W.; Lima, M.; Clauss, M. | year = 2009 | title = Gross anatomy of the intestine in the giraffe (''Giraffa camelopardalis'') | url = | journal = Anatomia, Histologia, Embryologia | volume = 38 | issue = 6| pages = 432–35 | pmid = 19681830 | doi=10.1111/j.1439-0264.2009.00965.x}}</ref> The liver of the giraffe is small and compact.<ref name=anatomy/>{{rp|76}} A gallbladder is generally present during fetal life, but it may disappear before birth.<ref name="Dagg1971"/><ref>{{cite journal | author=Cave, A. J. E. | title=On the liver and gall-bladder of the Giraffe | journal=Proceedings of the Zoological Society of London | volume=120 | pages=381–93 | year=1950 | doi=10.1111/j.1096-3642.1950.tb00956.x | issue=2}}</ref><ref>{{cite journal | author1=Oldham-Ott, Carla K. |author2=Gilloteaux, Jacques | title=Comparative morphology of the gallbladder and biliary tract in vertebrates: variation in structure, homology in function and gallstones | journal=Microscopy Research and Technique | volume=38 | issue=6 | pages=571–79 | year=1997 | doi=10.1002/(SICI)1097-0029(19970915)38:6<571::AID-JEMT3>3.0.CO;2-I}}</ref>
==Behavior and ecology==
===Habitat and feeding===
[[File:Giraffe feeding, Tanzania.jpg|thumb|Giraffe extending its tongue to feed. Its tongue, lips and palate are tough enough to deal with sharp thorns in trees.]]
Giraffes usually inhabit [[savanna]]s, [[grassland]]s and open [[woodland]]s. They prefer ''[[Acacia]]'', ''[[Commiphora]]'', ''[[Combretum]]'' and open ''[[Terminalia (plant)|Terminalia]]'' woodlands over denser environments like ''[[Brachystegia]]'' woodlands.<ref name=Kingdon1988/>{{rp|322}} The Angolan giraffe can be found in desert environments.<ref>{{cite thesis |author=Fennessy, J.|year=2004 |title=Ecology of desert-dwelling giraffe ''Giraffa camelopardalis angolensis'' in northwestern Namibia|publisher=[[University of Sydney]] |degree=[[Doctor of Philosophy|Ph.D.]] |url=http://ses.library.usyd.edu.au/handle/2123/910}}</ref> Giraffes browse on the twigs of trees, preferring trees of genera ''Acacia'', ''Commiphora'' and ''Terminalia'',<ref name=kingdon>{{Cite book|title=The Kingdon Field Guide to African Mammals|author=Kingdon, J.|publisher=Academic Press|pages=339–44|year=1997|isbn=0-12-408355-2}}</ref> which are important sources of calcium and protein to sustain the giraffe's growth rate.<ref name="Mitchell20003"/> They also feed on shrubs, grass and fruit.<ref name=Kingdon1988/>{{rp|324}} A giraffe eats around {{convert|34|kg|lb|abbr=on}} of foliage daily.<ref name=estes/> When stressed, giraffes may chew the bark off branches. Although [[herbivorous]], the giraffe has been known to visit carcasses and lick dried meat off bones.<ref name=Kingdon1988/>{{rp|325}}
During the wet season, food is abundant and giraffes are more spread out, while during the dry season, they gather around the remaining evergreen trees and bushes.<ref name=kingdon/> Mothers tend to feed in open areas, presumably to make it easier to detect predators, although this may reduce their feeding efficiency.<ref name=sexdiff /> As a [[ruminant]], the giraffe first chews its food, then swallows it for processing and then visibly passes the half-digested cud up the neck and back into the mouth to chew again.<ref name=anatomy/>{{rp|78-79}} It is common for a giraffe to salivate while feeding.<ref name=Williams/>{{rp|27}} The giraffe requires less food than many other herbivores, because the foliage it eats has more concentrated nutrients and it has a more efficient digestive system.<ref name=kingdon/> The animal's feces come in the form of small pellets.<ref name="Dagg1971"/> When it has access to water, a giraffe drinks at intervals no longer than three days.<ref name=estes/>
Giraffes have a great effect on the trees that they feed on, delaying the growth of young trees for some years and giving "waistlines" to trees that are too tall.<ref name=estes/> Feeding is at its highest during the first and last hours of daytime. Between these hours, giraffes mostly stand and ruminate. Rumination is the dominant activity during the night, when it is mostly done lying down.<ref name=estes/>
[[File:Giraffa camelopardalis angolensis (mating).jpg|thumb|left|Male giraffe mounting a female. Only dominant males are generally able to mate.]]
===Social life and breeding habits===
While giraffes are usually found in groups, the composition of these groups tends to be open and ever-changing.<ref name=Manyara>{{Cite journal|author= van der Jeugd, H. P; Prins, H. H. T. | title = Movements and group structure of giraffe (''Giraffa camelopardalis'') in Lake Manyara National Park, Tanzania| journal = Journal of Zoology | volume = 251| issue = 1| pages = 15–21| year = 2000| doi=10.1111/j.1469-7998.2000.tb00588.x|url=http://www.resource-ecology.org/publ/2000_Jeugd,Prins_MovementsAndGroupStructureOfGiraffeInLakeManyara.pdf}}</ref> They have few strong social bonds, and aggregations usually change members every few hours. For research purposes, a "group" has been defined as "a collection of individuals that are less than a kilometre apart and moving in the same general direction."<ref name= "Pratt 1985">{{cite journal | doi = 10.1080/00222938500770471 | author = Pratt D. M.; Anderson V. H. | year = 1985 | title = Giraffe social behavior | journal = Journal of Natural History | volume = 19 | issue = 4 | pages = 771–81 }}</ref> The number of giraffes in a group can range up to 32 individuals.<ref name=Manyara/> The most stable giraffe groups are those made of mothers and their young,<ref name= "Pratt 1985"/> which can last weeks or months.<ref name= "Leuthold 1979"/> Social cohesion in these groups is maintained by the bonds formed between calves.<ref name=Kingdon1988/>{{rp|330}}<ref name= "Pratt 1985"/> Mixed-sex groups made of adult females and young males are also known to occur.<ref name= "Pratt 1985"/> Subadult males are particularly social and will engage in playfights. However, as they get older males become more solitary.<ref name= "Leuthold 1979"/<ref name= "Leuthold 1979"/> Giraffes are not territorial,<ref name="Dagg1971"/> but they have [[home range]]s.<ref name=estes/> Male giraffes occasionally wander far from areas that they normally frequent.<ref name=Kingdon1988/>{{rp|329}}
Reproduction is broadly polygamous: a few older males mate with the fertile females. Male giraffes assess female fertility by tasting the female's urine to detect [[estrus]], in a multi-step process known as the [[Flehmen response]].<ref name= "Pratt 1985"/><ref name= "Leuthold 1979">{{Cite journal|author=Leuthold, B. M.|year=1979|title=Social organization and behaviour of giraffe in Tsavo East National Park|journal=African Journal of Ecology|volume=17|issue=1|pages=19–34|doi=10.1111/j.1365-2028.1979.tb00453.x}}</ref> Males prefer young adult females over juveniles and older adults.<ref name= "Pratt 1985"/> Once an estrous female is detected, the male will attempt to court her. When courting, dominant males will keep subordinate ones at bay.<ref name= "Leuthold 1979"/> During copulation, the male stands on its hind legs with its head held up and its front legs resting on the female's sides.<ref name=estes/>
Although generally quiet and non-vocal, giraffes have been heard to communicate using various sounds. During courtship, males emit loud coughs.<ref name=estes/> Females call their young by bellowing. Calves will emit snorts, bleats, mooing and mewing sounds. Giraffes also snore, hiss, moan and make flute-like sounds,<ref name=estes/> and they communicate over long distances using [[infrasound]].<ref>{{cite web|title=Silent Sentinels?|publisher=PBS online – Nature|url=http://www.pbs.org/wnet/nature/episodes/tall-blondes/silent-sentinels/2256/|accessdate=2011-12-21}}</ref>
===Birthing and parental care===
[[File:Giraffe Family.jpg|thumb||Mother giraffe and calves feeding. It is mostly the females that raise young, and they may gather in nursery herds.]]
Giraffe [[gestation]] lasts 400–460 days, after which a single calf is normally born, although twins occur on rare occasions.<ref name=ap>{{Cite web|title=Mammal Guide – Giraffe|publisher=[[Animal Planet]]|url=http://animal.discovery.com/guides/mammals/habitat/tropgrassland/giraffe.html|accessdate=2009-03-07}}</ref> The mother gives birth standing up. The calf emerges head and front legs first, having broken through the [[fetal membrane]]s, and falls to the ground, severing the [[umbilical cord]].<ref name="Dagg1971"/> The mother then grooms the newborn and helps it stand up.<ref name=Williams/>{{rp|40}} A newborn giraffe is about {{convert|1.8|m|ft|abbr=on|sigfig=1}} tall. Within a few hours of birth, the calf can run around and is almost indistinguishable from a one-week-old. However, for the first 1–3 weeks, it spends most of its time hiding;<ref name="Langman 1977">{{Cite journal|author=Langman, V. A.|year=1977|title=Cow-calf relationships in giraffe (''Giraffa camelopardalis giraffa'')|journal=Zeitschrift fur Tierpsychologie|volume=43|issue=3|pages=264–86}} [[Digital object identifier|doi]]:[http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0310.1977.tb00074.x/abstract 10.1111/j.1439-0310.1977.tb00074.x]</ref> its coat pattern providing camouflage. The ossicones, which have lain flat while it was in the womb, become erect within a few days.<ref name=estes/>
Mothers with calves will gather in nursery herds, moving or browsing together. Mothers in such a group may sometimes leave their calves with one female while they forage and drink elsewhere. This is known as a "calving pool".<ref name= "Langman 1977"/> Adult males play almost no role in raising the young,<ref name=Kingdon1988/>{{rp|337}} although they appear to have friendly interactions.<ref name= "Pratt 1985"/> Calves are at risk of predation, and a mother giraffe will stand over her calf and kick at an approaching predator.<ref name=estes/> Females watching calving pools will only alert their own young if they detect a disturbance, although the others will take notice and follow.<ref name= "Langman 1977"/> The bond a mother shares with her calf varies, though it can last until her next calving.<ref name= "Langman 1977"/> Likewise, calves may suckle for only a month<ref name=Kingdon1988/>{{rp|335}} or as long as a year.<ref name=estes/><ref name= "Leuthold 1979"/> Females become sexually mature when they are four years old, while males become mature at four or five years. However, males must wait until they are at least seven years old to gain the opportunity to mate.<ref name=estes/><ref name=Williams/>{{rp|40}}
===Necking===
[[File:Giraffe Ithala KZN South Africa Luca Galuzzi 2004.JPG|thumb|Male giraffes will engage in necking to establish dominance.]]
Male giraffes use their necks as weapons in combat, a behavior known as "necking". Necking is used to establish dominance and males that win necking bouts have greater reproductive success.<ref name=sim1996/> This behavior occurs at low or high intensity. In low intensity necking, the combatants rub and lean against each other. The male that can hold itself more erect wins the bout.<ref name=estes/> In high intensity necking, the combatants will spread their front legs and swing their necks at each other, attempting to land blows with their ossicones. The contestants will try to dodge each other's blows and then get ready to counter. The power of a blow depends on the weight of the skull and the arc of the swing.<ref name=estes/> A necking duel can last more than half an hour, depending on how well matched the combatants are.<ref name=Kingdon1988/>{{rp|331}}
After a duel, it is common for two male giraffes to caress and court each other, leading up to mounting and climax. Such interactions between males have been found to be more frequent than heterosexual coupling.<ref>{{Cite journal|author=Coe, M. J.|year=1967|title='Necking' behavior in the giraffe|journal=Journal of Zoology|volume=151|issue=2|pages=313–21|doi= 10.1111/j.1469-7998.1967.tb02117.x}}</ref> In one study, up to 94 percent of observed mounting incidents took place between males. The proportion of same-sex activities varied from 30–75 percent. Only one percent of same-sex mounting incidents occurred between females.<ref>{{Cite book|author=Bagemihl, B.|year= 1999|title=Biological Exuberance: Animal Homosexuality and Natural Diversity| publisher=St. Martin's Press| pages=391–93|isbn= 0-312-19239-8}}</ref>
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[[File:Lioness_with_giraffe_kill,_jackal_lurking,_kenya,_august_9th_2012.jpg|thumb|right|Lioness seen with adult giraffe kill]]
Giraffes have an unusually long lifespan compared to other ruminants,<ref>{{Cite journal|author=Müller, D.W.; Zerbe, P; Codron, D; Clauss, M; Hatt, J.M.|year=2011|title=A long life among ruminants: giraffids and other special cases|journal=Schweizer Archiv für Tierheilkunde|volume=153|issue=11|pages=515–519|pmid=22045457|doi=10.1024/0036-7281/a000263}}</ref> up to 25 years in the wild.<ref name= "MacDonald"/> Because of their size, eyesight and powerful kicks, adult giraffes are usually not subject to predation.<ref name=estes/> However, they can fall prey to [[lion]]s and are regular prey for them in [[Kruger National Park]].<ref>{{Cite journal|author=Owen-Smith, N.; Mills, M. G.|year=2008|title= Predator-prey size relationships in an African large-mammal food web|journal=Journal of Animal Ecology|volume=77|issue=1|pages= 173–83|pmid= 18177336|url= http://137.215.9.22/bitstream/handle/2263/9023/Owen-Smith_Predator-prey(2008).pdf?sequence=1|doi=10.1111/j.1365-2656.2007.01314.x}}</ref> [[Nile crocodile]]s can also be a threat to giraffes when they bend down to drink.<ref name=Williams/>{{rp|31}} Calves are much more vulnerable than adults, and are additionally preyed on by [[leopard]]s, [[spotted hyena]]s and [[Lycaon pictus|wild dogs]].<ref name="Prothero 2003"/> A quarter to a half of giraffe calves reach adulthood.
Some parasites feed on giraffes. They are often hosts for [[tick]]s, especially in the area around the genitals, which has thinner skin than other areas.<ref name="Dagg1971"/> Tick species that commonly feed on giraffes are those of genera ''[[Hyalomma]]'', ''[[Amblyomma]]'' and ''[[Rhipicephalus]]''. Giraffes may rely on [[Red-billed Oxpecker|red-billed]] and [[yellow-billed oxpecker]]s to clean them of ticks and alert them to danger. Giraffes host numerous species of internal parasite and are susceptible to various diseases. They were victims of the (now eradicated) viral illness [[rinderpest]].<ref name="Dagg1971"/>
==Relationship with humans==
===Cultural significance===
[[File:Giraffe cave art.jpg|thumb|Bushman rock art in Namibia depicting a giraffe]]
Humans have interacted with giraffes for millennia. The [[Bushmen]] of southern Africa have medicine dances named after some animals; the giraffe dance is performed to treat head ailments.<ref>{{Cite book|author=Ross, K.|year=2003|title=Okavango: jewel of the Kalahari|publisher=Struik|page=168|isbn=1-86872-729-7}}</ref> How the giraffe got its height has been the subject of various African [[folktales]],<ref name=sim1996/> including one from eastern Africa which explains that the giraffe grew tall from eating too many magic herbs.<ref>{{cite book|author=Greaves, N.; Clement, R.|year=2000|title=When Hippo Was Hairy: And Other Tales from Africa|publisher=Struik|pages=86–88|isbn=1-86872-456-5}}</ref> Giraffes were depicted in art throughout the African continent, including that of the [[Kiffian culture|Kiffians]], [[Ancient Egypt|Egyptians]] and [[Meroë|Meroë Nubians]].<ref name=Williams>{{Cite book|author=Williams, E.|year=2011|title=Giraffe|publisher=Reaktion Books|isbn=1-86189-764-2}}</ref>{{rp|45–47}} The Kiffians were responsible for a life-size rock engraving of two giraffes that has been called the "world's largest rock art petroglyph".<ref name=Williams/>{{rp|45}}<ref>{{Cite web|url=http://www.bradshawfoundation.com/giraffe/|title=The Dabous Giraffe rock art petrograph|publisher=The Bradshaw Foundation|accessdate=2011-11-06}}</ref> The Egyptians gave the giraffe its own [[Egyptian hieroglyphs|hieroglyph]], named 'sr' in [[Old Egyptian language|Old Egyptian]] and 'mmy' in later periods.<ref name=Williams/>{{rp|49}} They also kept giraffes as pets and shipped them around the [[Mediterranean]].<ref name=Williams/>{{rp|48–49}}
[[File:Yongle-Giraffe1.jpg|thumb|left|Painting of a giraffe imported to China during the Ming Dynasty]]
The giraffe was also known to the [[Ancient Greece|Greeks]] and [[Ancient Rome|Romans]], who believed that it was an unnatural hybrid of a [[camel]] and a leopard and called it ''camelopardalis''.<ref name=Williams/>{{rp|50}} The giraffe was among the many animals collected and displayed by the Romans. The first one in Rome was brought in by [[Julius Caesar]] in 46 BC and exhibited to the public.<ref name=Williams/>{{rp|52}} With the [[fall of the Roman Empire]], the housing of giraffes in Europe declined.<ref name=Williams/>{{rp|54}} During the [[Middle Ages]], giraffes were only known to Europeans through contact with the Arabs, who revered the giraffe for its peculiar appearance.<ref name="Prothero 2003">{{Cite book|author=Prothero, D. R.; Schoch, R. M.|year=2003|title=Horns, Tusks, and Flippers: The Evolution of Hoofed Mammals|publisher=Johns Hopkins University Press|pages=67–72|isbn=0-8018-7135-2}}</ref>
In 1414, a giraffe was shipped from [[Malindi]] to [[Bengal]]. It was then taken to China by explorer [[Zheng He]] and placed in a [[Ming Dynasty]] zoo. The animal was a source of fascination for the Chinese people, who associated it with the mythical [[Qilin]].<ref name=Williams/>{{rp|56}} The [[Medici giraffe]] was a giraffe presented to [[Lorenzo de' Medici]] in 1486. It caused a great stir on its arrival in Florence,<ref>{{Cite journal|pdf=http://www.archive.org/download/ErikRingmaraudienceForAGiraffeEuropeanExceptionalismAndTheQuest_744/ErikRingmarAudienceForAGiraffe.pdf |title=Audience for a Giraffe: European Expansionism and the Quest for the Exotic|author= Ringmar, E.|journal= Journal of World History| year = 2006| volume = 17| issue = 4| pages = 353–97 |jstor = 20079397|doi=10.1353/jwh.2006.0060}}</ref> being reputedly the first living giraffe to be seen in Italy since antiquity. Another [[Giraffe given to Charles X of France by Muhammad Ali of Egypt|famous giraffe]] was brought from Egypt to Paris in the early 19th century. A sensation, the giraffe was the subject of numerous memorabilia or "giraffanalia".<ref name=Williams/>{{rp|81}}
Giraffes continue to have a presence in modern culture. [[Salvador Dalí]] depicted them with [[conflagration|conflagrated]] manes in some of his surrealist paintings. Dali considered the giraffe to be a symbol of masculinity, and a flaming giraffe was meant to be a "masculine cosmic apocalyptic monster".<ref name=Williams/>{{rp|123}} Several children's books feature the giraffe, including David A. Ufer's ''The Giraffe Who Was Afraid of Heights'', [[Giles Andreae]]'s ''Giraffes Can't Dance'' and [[Roald Dahl]]'s ''[[The Giraffe and the Pelly and Me]]''. Giraffes have appeared in animated films, as minor characters in [[Disney]]'s ''[[The Lion King]]'' and ''[[Dumbo]]'', and in more prominent roles in ''[[The Wild]]'' and in the ''[[Madagascar (franchise)|Madagascar]]'' films. [[Sophie the Giraffe]] has been a popular [[teether]] since 1961. Another famous fictional giraffe is the Toys "R" Us mascot [[Toys "R" Us#Geoffrey the Giraffe|Geoffrey the Giraffe]].<ref name=Williams/>{{rp|127}} The giraffe is also the [[national animal]] of Tanzania.<ref>{{Cite book |title=East Africa: Kenya, Tanzania & Uganda |author=Knappert, J |authorlink=Jan Knappert |year=1987 |publisher=Vikas Publishing House|isbn= 0-7069-2822-9 |page=57}}</ref>
The giraffe has also been used for some scientific experiments and discoveries. Scientists have looked at the properties of giraffe skin when developing suits for astronauts and fighter pilots.<ref name=anatomy/>{{rp|76}} This is because the people in these professions are in danger of passing out if blood rushes to their legs. Computer scientists have modeled the coat patterns of several subspecies using [[reaction-diffusion|reaction–diffusion]] mechanisms.<ref>{{Cite journal|author=Walter, M.; Fournier, A.; Menevaux, D.|year=2001|title= Integrating shape and pattern in mammalian models in SIGGRAPH '01|journal=Proceedings of the 28th annual conference on Computer graphics and interactive techniques|pages= 317–26 |doi= 10.1145/383259.383294|url =http://www.csun.edu/~renzo/GraphicsResources/Articles/walter.pdf|isbn=1-58113-374-X}}</ref> The [[constellation]] of [[Camelopardalis]], introduced in the seventeenth century, depicts a giraffe.<ref name=Williams/>{{rp|119–20}}
===Exploitation and conservation status===
[[File:Bundesarchiv Bild 105-DOA0377, Deutsch-Ostafrika, Giraffe.jpg|thumb|Giraffe killed by tribesmen in the early 20th century]]
Giraffes were probably common targets for hunters throughout Africa.<ref name=Kingdon1988/>{{rp|337}} Different parts of their bodies were used for different purposes.<ref name="Dagg1971"/> Their meat was used for food. The tail hairs served as [[flyswatter]]s, bracelets, necklaces and thread.<ref name=Kingdon1988/>{{rp|337}}<ref name="Dagg1971"/> Shields, sandals and drums were made using the skin, and the strings of musical instruments were from the tendons.<ref name="Dagg1971"/> The smoke from burning giraffe skins was used by the medicine men of [[Buganda]] to treat nose bleeds.<ref name=Kingdon1988/>{{rp|337}} In the 19th Century, European explorers begin hunting them for sport.<ref name=Williams/>{{rp|129}} Habitat destruction has hurt the giraffe, too: in the [[Sahel]], the need for firewood and grazing room for livestock has led to [[deforestation]]. Normally, giraffes can coexist with livestock, since they do not directly compete with them.<ref name= "MacDonald"/>
The giraffe species as a whole is assessed as [[Least Concern]] from a conservation perspective by the [[International Union for Conservation of Nature|IUCN]], as it is still numerous. However, giraffes have been [[extirpated]] from much of their historic range including [[Eritrea]], [[Guinea]], [[Mauritania]] and [[Senegal]]. They may also have disappeared from [[Angola]], [[Mali]], and [[Nigeria]], but have been introduced to [[Rwanda]] and [[Swaziland]].<ref name=iucn/> Two subspecies, the [[West African giraffe]] and the [[Rothschild giraffe]], have been classified as [[Endangered species|Endangered]],<ref name=IUCNrothschildi/><ref name=IUCNperalta/> as wild populations of each of them number in the hundreds.<ref name=wildstatus/> In 1997, [[Jonathan Kingdon]] suggested that the [[Nubian giraffe]] was the most threatened of all giraffes;<ref name=kingdon/> {{as of|2010|lc=y}}, it may number fewer than 250, although this estimate is uncertain.<ref name=wildstatus/> Private game reserves have contributed to the preservation of giraffe populations in southern Africa.<ref name= "MacDonald"/> [[Giraffe Manor]] is a popular hotel in [[Nairobi]] which also serves a sanctuary for Rothschild's giraffes.<ref>{{cite web|author=Lord. M|date=2012-01-11|title=Outlandish Outposts: Giraffe Manor in Kenya|publisher=Forbes.com|accessdate=2012-04-04|url=http://www.forbes.com/sites/forbestravelguide/2012/01/11/outlandish-outposts-giraffe-manor-in-kenya/}}</ref> The giraffe is a protected species in most of its range. In 1999, it was estimated that over 140,000 giraffes existed in the wild, but estimates in 2010 indicate that fewer than 80,000 remain.<ref name=wildstatus/>
{{Tassobox
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===Notes===
{{References|2}}
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