Editing Giraffe (section)

==Anatomy==
[[File:Giraffe skeleton.jpg|thumb|upright|alt=Photograph of a Giraffe skeleton|Giraffe skeleton on display at the [[Museum of Osteology]], [[Oklahoma City]]]]
Fully grown giraffes stand {{cvt|4.3|–|5.7|m}} tall, with [[sexual dimorphism|males taller]] than females.<ref name=Nowak1999>{{cite book|author=Nowak, R.M. |date=1999 |url=https://books.google.com/books?id=7W-DGRILSBoC&pg=PA1086 |pages=1086–1089|title=Walker's Mammals of the World |volume=1 |publisher=The [[Johns Hopkins University Press]] |isbn=978-0801857898|access-date=30 August 2021|archive-date=22 September 2023|archive-url=https://web.archive.org/web/20230922073614/https://books.google.com/books?id=7W-DGRILSBoC&pg=PA1086|url-status=live}}</ref> The average weight is {{cvt|1192|kg}} for an adult male and {{cvt|828|kg}} for an adult female.<ref name=Skinner1990>{{Cite book|author1=Skinner, J. D. |author2=Smithers, R. H. M. |year=1990|title=The mammals of the southern African subregion |pages=616–20|publisher=[[University of Pretoria]]|isbn=978-0-521-84418-5}}</ref> Despite its long neck and legs, its body is relatively short.<ref name=anatomy/>{{rp|66}} The skin is mostly gray<ref name=Skinner1990/> or tan,<ref>{{cite web |author=Langley, L. |date=2017 |title=Do zebras have stripes on their skin?|publisher=[[National Geographic]]|access-date=2 June 2020 |url=https://www.nationalgeographic.com/news/2017/03/animals-skin-colors-zebras-big-cats/|archive-date=1 April 2019|archive-url=https://web.archive.org/web/20190401134219/https://news.nationalgeographic.com/2017/03/animals-skin-colors-zebras-big-cats/|url-status=dead}}</ref> and can reach a thickness of {{cvt|20|mm}}.<ref name=Dagg2014/>{{rp|87}} The {{cvt|80|–|100|cm}} long<ref name=MacDonald/> tail ends in a long, dark tuft of hair and is used as a defense against insects.<ref name=Dagg2014/>{{rp|94}}

The [[Animal coat|coat]] has dark blotches or patches, which can be orange, [[Chestnut (color)|chestnut]], brown, or nearly black, surrounded by light hair, usually white or [[Cream (colour)|cream]] coloured.<ref name="Prothero 2003"/> Male giraffes become darker as they grow old.<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=202–207 |year=1992 |isbn=978-0-520-08085-0 |url=https://archive.org/details/isbn_0520080858/page/202}}</ref> The coat pattern [[Disruptive coloration#A disputed case: the giraffe|has been claimed]] to serve as [[camouflage]] in the light and shade patterns of savannah woodlands.<ref name=MacDonald/> When standing among trees and bushes, they are hard to see at even a few metres distance. However, adult giraffes move about to gain the best view of an approaching predator, relying on their size and ability to defend themselves rather than on camouflage, which may be more important for calves.<ref name=Mitchell20003/> Each giraffe has a unique coat pattern.<ref>{{Cite journal |last=Foster |first=J. B. |title=The Giraffe of Nairobi National Park: Home range, sex ratios, the herd, and food |date=1966 |journal=African Journal of Ecology |volume=4 |issue=1 |pages=139–148 |doi=10.1111/j.1365-2028.1966.tb00889.x |bibcode=1966AfJEc...4..139F |archive-date=14 December 2022 |url-status=live |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2028.1966.tb00889.x |archive-url=https://web.archive.org/web/20221214102948/https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2028.1966.tb00889.x}}</ref><ref>{{Cite journal |last1=Lee |first1=D. E. |last2=Lohay |first2=G. G. |last3=Cavener |first3=D. R. |last4=Bond |first4=M. L. |date=2022 |title=Using spot pattern recognition to examine population biology, evolutionary ecology, sociality, and movements of giraffes: a 70-year retrospective |url=https://doi.org/10.1007/s42991-022-00261-3 |journal=[[Mammalian Biology]] |volume=102 |issue=4 |pages=1055–1071 |doi=10.1007/s42991-022-00261-3 |s2cid=252149865 |access-date=14 December 2022 |archive-date=22 September 2023 |archive-url=https://web.archive.org/web/20230922073617/https://link.springer.com/article/10.1007/s42991-022-00261-3 |url-status=live}}</ref> Calves inherit some coat pattern traits from their mothers, and variation in some spot traits is correlated with calf survival.<ref name=Lee2018>{{Cite journal|last1=Lee|first1=D. E.|last2=Cavener|first2=D. R.|last3=Bond|first3=M. L.|date=2018 |title=Seeing spots: quantifying mother-offspring similarity and assessing fitness consequences of coat pattern traits in a wild population of giraffes (''Giraffa camelopardalis'') |journal=[[PeerJ]] |volume=6 |pages=e5690|doi=10.7717/peerj.5690|pmid=30310743|pmc=6173159 |doi-access=free}}</ref> The skin under the blotches may regulate the animal's body temperature, being sites for complex blood vessel systems and large [[sweat gland]]s.<ref name=Mitchell2004>{{Cite journal |author1=Mitchell, G. |author2=Skinner, J.D. |year=2004 |title=Giraffe thermoregulation: a review |journal=[[Transactions of the Royal Society of South Africa]] |volume=59 |issue=2 |pages=49–57 |url=http://www.sabinet.co.za/abstracts/royalsa/royalsa_v59_n2_a13.html |doi=10.1080/00359190409519170 |bibcode=2004TRSSA..59..109M |s2cid=87321176 |access-date=19 October 2011 |archive-date=20 November 2018 |archive-url=https://web.archive.org/web/20181120033724/https://www.sabinet.co.za/abstracts/royalsa/royalsa_v59_n2_a13.html |url-status=live}}</ref> Spotless or solid-color giraffes are very rare, but have been observed.<ref name="National Geographic 12 September 2023">{{cite news |last1=Fine Maron |first1=Dina |title=Another rare spotless giraffe found—the first ever seen in the wild |url=https://www.nationalgeographic.com/animals/article/spotless-giraffe-found-in-the-wild-for-the-first-time |access-date=6 March 2024 |work=[[National Geographic]] |date=12 September 2023 |language=en}}</ref><ref name="NPR 6 September 2023">{{cite news |last1=Romo |first1=Vanessa |last2=Jones |first2=Dustin |title=A rare spotless giraffe gets a name to match |url=https://www.npr.org/2023/09/06/1197789671/a-rare-spotless-giraffe-gets-a-name-to-match |access-date=6 March 2024 |work=[[NPR]] |date=6 September 2023}}</ref>

The fur may give the animal chemical defense, as its parasite repellents give it a characteristic scent. At least 11 main [[aromaticity|aromatic]] chemicals are in the fur, although [[indole]] and [[3-methylindole]] are responsible for most of the smell. Because males have a stronger odour than females, it may also have a [[Animal sexual behaviour|sexual function]].<ref>{{Cite journal|author1=Wood, W. F. |author2=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|bibcode=2002BioSE..30..913W }}</ref>

===Head===
[[File:Giraffa camelopardalis head (Profil).jpg|thumb|left|alt=Closeup photograph of a giraffe head|Closeup of the head of a [[northern giraffe]]]]
Both sexes have prominent horn-like structures called [[ossicone]]s, which can reach {{cvt|13.5|cm}}. They are formed from [[Ossification|ossified]] [[cartilage]], covered in skin, and fused to the [[skull]] at the [[parietal bone]]s.<ref name=estes/><ref name=Dagg2014/>{{rp|95–97}} Being [[Blood vessel|vascular]]ised, the ossicones may have a role in [[thermoregulation]],<ref name=Mitchell2004/> and are 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 tend to be bald and knobbed on top.<ref name=estes/> A lump, which is more prominent in males, emerges in the middle of the skull.<ref name=Dagg1971/> Males develop [[calcium]] deposits that form bumps on their skulls as they age.<ref name="Prothero 2003"/> Multiple [[Sinus (anatomy)|sinuses]] lighten a giraffe's skull.<ref name=Dagg2014/>{{rp|103}} However, as males age, their skulls become heavier and more club-like, helping them become more dominant in combat.<ref name=estes/> The [[occipital condyles]] at the bottom of the skull allow the animal to tip its head over 90 degrees and grab food on the branches directly above them with the tongue.<ref name=Dagg2014/>{{rp|103, 110}}<ref name=Dagg1971/>

With eyes located on the sides of the head, the giraffe has a broad [[Field of view|visual field]] from its great height.<ref name=Dagg2014>{{cite book|author=Dagg, A. I.|year=2014|title=Giraffe: Biology, Behaviour, and Conservation|publisher=[[Cambridge University Press]] |isbn=978-1107610170}}</ref>{{rp|85, 102}} Compared to other [[ungulate]]s, giraffe vision is more [[binocular vision|binocular]] and the eyes are larger with a greater [[retina]]l surface area.<ref>{{cite journal|last1=Mitchell|first1=G.|last2=Roberts|first2=D. G.|last3=van Sittert |first3=S. J.|last4=Skinner|first4=J. D.|year=2013|title=Orbit orientation and eye morphometrics in giraffes (''Giraffa camelopardalis'') |journal=[[African Zoology]] |volume=48|issue=2|pages=333–339 |doi=10.1080/15627020.2013.11407600 |hdl=2263/37109 |s2cid=219292664 |hdl-access=free}}</ref> Giraffes may see in colour,<ref name=Dagg2014/>{{rp|85}} and their senses of hearing and [[olfaction|smell]] are sharp.<ref name="Prothero 2003"/> The ears are movable.<ref name=Dagg2014/>{{rp|95}} The nostrils are slit-shaped, possibly to withstand blowing sand.<ref>{{cite book|author=Peterson, D.|year=2013 |title=Giraffe Reflections |publisher=[[University of California Press]] |page=30 |isbn=978-0520266858}}</ref> The giraffe's [[tongue]] is about {{cvt|45|cm}} long. It is black, perhaps to protect against sunburn, and can [[prehensile|grasp]] foliage and delicately pick off leaves.<ref name=Dagg2014/>{{rp|109–110}} The upper lip is flexible and hairy to protect against sharp prickles.<ref name="Dagg1971"/> The upper jaw has a hard [[palate]] instead of front teeth. The [[Molar (tooth)|molar]]s and [[premolar]]s are wide with low [[Crown (tooth)|crowns]] on the surface.<ref name=Dagg2014/>{{rp|106}}

===Neck===
The giraffe has an extremely elongated neck, which can be up to {{cvt|2.4|m|ft}} in length.<ref name="Taylor&Wedel2013">{{Cite journal |last1=Taylor |first1=M. P. |last2=Wedel |first2=M. J. |doi=10.7717/peerj.36 |title=Why sauropods had long necks; and why giraffes have short necks |journal=[[PeerJ]] |volume=1 |page=e36 |year=2013 |pmid=23638372 |pmc=3628838 |doi-access=free}}</ref> Along the neck is a mane made of short, erect hairs.<ref name="Dagg1971"/> The neck typically rests at an angle of 50–60 degrees, though juveniles are closer to 70 degrees.<ref name=Dagg2014/>{{rp|72–73}} The long neck results from a disproportionate lengthening of the [[cervical vertebrae]], not from the addition of more vertebrae. Each cervical vertebra is over {{cvt|28|cm}} 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]] |pages=64–84 |isbn=978-0-7614-7882-9}}</ref>{{rp|71}} They comprise 52–54 per cent 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 |last1=Badlangana |first1=L. N. |last2=Adams |first2=J. W. |last3=Manger |first3=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=736–757 |year=2009 |doi-access=free}}</ref> This elongation largely takes place after birth, perhaps because 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 |pmid=20700891 |last1=Van Sittert |first1=S. J. |last2=Skinner |first2=J. D. |last3=Mitchell |first3=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=469–479 |year=2010|bibcode=2010JEZB..314..469V }}</ref> The giraffe's head and neck are held up by large muscles and a [[nuchal ligament]], which are anchored by long [[thoracic vertebrae]] spines, giving them a hump.<ref name=Dagg1971/><ref name=Solounias1999/><ref name=MacDonald/>

[[File:Flickr - Rainbirder - High-rise living.jpg|thumb|left|upright|alt=Photograph of an adult male giraffe with its next fully extended feeding on an acacia|Adult male [[reticulated giraffe]] feeding high on an acacia, in Kenya]]
The giraffe's neck vertebrae have [[ball and socket joint]]s.<ref name=anatomy/>{{rp|71}} 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 in 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 name=Solounias1999>{{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=257–268 |doi=10.1111/j.1469-7998.1999.tb00989.x |url=http://www.ikhebeenvraag.be/mediastorage/FSDocument/73/download.pdf |archive-url=https://web.archive.org/web/20090325215447/http://www.ikhebeenvraag.be/mediastorage/FSDocument/73/download.pdf |archive-date=25 March 2009 |url-status=live}}</ref> However, this proposition is not generally accepted, as T1 has other [[morphology (biology)|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 characterised by increased [[neurological disorder|neurological anomalies]] and maladies.<ref name=bada/>

There are several 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 |last1=Simmons |first1= R. E. |last2=Altwegg |first2=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> [[Charles Darwin]] originally suggested the "competing [[browsing (predation)|browsers]] hypothesis", which has been challenged only recently. It suggests that competitive pressure from smaller browsers, like [[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 {{cvt|4.5|m}} high, while even quite large competitors, such as kudu, can feed up to only about {{cvt|2|m}} 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 |bibcode=1990AfJEc..28...55D |url=http://courses.biology.utah.edu/goller/7406/Goller7406/duToitPdfs/Feedingheightstrat_1990.pdf |access-date=21 November 2011 |url-status=dead|archive-date=10 November 2011 |archive-url=https://web.archive.org/web/20111110224355/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 |last1=Cameron |first1=E. Z.|author-link=Elissa Cameron |last2=du Toit|first2=J. T.|year=2007|title=Winning by a Neck: Tall Giraffes Avoid Competing with Shorter Browsers |url=http://ecite.utas.edu.au/67394 |journal=[[American Naturalist]] |volume=169 |issue=1 |pages=130–135 |doi=10.1086/509940|pmid=17206591|bibcode=2007ANat..169..130C |s2cid=52838493|access-date=5 December 2019|archive-date=2 June 2020 |archive-url=https://web.archive.org/web/20200602031844/http://ecite.utas.edu.au/67394|url-status=live}}</ref><ref>{{Cite journal |author1=Woolnough, A. P. |author2=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=585–590 |year=2001 |doi=10.1007/s004420100771| pmid=24577699  |bibcode=2001Oecol.129..585W|s2cid=18821024 |url=http://courses.biology.utah.edu/goller/7406/Goller7406/duToitPdfs/Verticalzonation_2001.pdf| access-date=7 March 2012| archive-url=https://web.archive.org/web/20111110224921/http://courses.biology.utah.edu/goller/7406/Goller7406/duToitPdfs/Verticalzonation_2001.pdf| archive-date=10 November 2011 |url-status=dead}}</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| author1=Young, T. P.| author2=Isbell, L. A.| title=Sex differences in giraffe feeding ecology: energetic and social constraints |journal=[[Ethology (journal)|Ethology]]| volume=87| issue=1–2| pages=79–89| year=1991 |doi=10.1111/j.1439-0310.1991.tb01190.x | bibcode=1991Ethol..87...79Y|url=http://tpyoung.ucdavis.edu/publications/1991GiraffesEthology.pdf| access-date=2 February 2012| archive-url=https://web.archive.org/web/20130516034426/http://tpyoung.ucdavis.edu/publications/1991GiraffesEthology.pdf| archive-date=16 May 2013| url-status=dead}}</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|author1=Mitchell, G. |author2=van Sittert, S. |author3=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=165–168|doi=10.1080/0035919X.2010.509153|bibcode=2010TRSSA..65..165M |hdl=2263/18957 |s2cid=83652889 |hdl-access=free}}</ref>

Another theory, the [[sexual selection]] hypothesis, proposes that 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 |author1=Simmons, R. E.|author2=Scheepers, L. |title=Winning by a Neck: Sexual Selection in the Evolution of Giraffe |journal=[[The American Naturalist]] |volume=148 |issue=5| pages=771–786 |year=1996 |url=http://bill.srnr.arizona.edu/classes/182/Giraffe/WinningByANeck.pdf |doi=10.1086/285955 |bibcode=1996ANat..148..771S |s2cid=84406669 |url-status=dead| archive-url=https://web.archive.org/web/20040823200801/http://bill.srnr.arizona.edu/classes/182/Giraffe/WinningByANeck.pdf| archive-date=23 August 2004}}</ref> In support of this theory, some studies have stated that necks are longer and heavier for males than females of the same age,<ref name=sim1996/><ref name=sim2010/> and that males do not employ other forms of combat.<ref name=sim1996/> However, a 2024 study found that, while males have thicker necks, females actually have proportionally longer ones, which is likely because of their greater need to find more food to sustain themselves and their dependent young.<ref name=Cavener2024>{{cite journal|last1=Cavener|first1=D. R.|last2=Bond|first2=M. L.|last3=Wu-Cavener|first3=L|last4=Lohay|first4=G. G.|last5=Cavener|first5=M. W.|last6=Hou|first6=X|last7=Pearce|first7=D. L.|last8=Lee|first8=D. E.|year=2024|title=Sexual dimorphisms in body proportions of Masai giraffes and the evolution of the giraffe's neck|journal=Mammalian Biology|volume=104 |issue=5 |pages=513–527 |doi=10.1007/s42991-024-00424-4|doi-access=free}}</ref> It has also been proposed that the neck serves to give the animal greater vigilance.<ref>{{cite journal|author=Brownlee, A. |year=1963|title=Evolution of the Giraffe|journal=[[Nature (journal)|Nature]] |volume=200 |issue=4910 |page=1022 |doi=10.1038/2001022a0 |bibcode=1963Natur.200.1022B|s2cid=4145785|doi-access=free}}</ref><ref>{{cite journal |last1=Williams|first1=E. M.|title=Giraffe Stature and Neck Elongation: Vigilance as an Evolutionary Mechanism |journal=Biology |volume=5 |issue=3 |page=35 |doi=10.3390/biology5030035 |year=2016 |pmc=5037354 |pmid=27626454 |doi-access=free}}</ref>

===Legs, locomotion and posture===
[[File:Masai Giraffe right-rear foot.jpg|thumb|upright|left|alt=Photograph of giraffe's hind leg|Right hind leg of a Masai giraffe at the [[San Diego Zoo]]]]
The front legs tend to be longer than the hind legs,<ref name=Dagg2014/>{{rp|109}} and males have proportionally longer front legs than females, which gives them better support when swinging their necks during fights.<ref name=Cavener2024/> The leg bones lack first, second and fifth [[metapodial]]s.<ref name=Dagg2014/>{{rp|109}} It appears that a [[suspensory ligament]] allows the lanky legs to support the animal's great weight.<ref>{{cite web |author=Wood, C. |date=2014 |title=Groovy giraffes...distinct bone structures keep these animals upright|publisher=[[Society for Experimental Biology]] |url=http://www.eurekalert.org/pub_releases/2014-07/sfeb-ggd070314.php|access-date=7 May 2014|archive-date=25 November 2018|archive-url=https://web.archive.org/web/20181125074805/https://www.eurekalert.org/pub_releases/2014-07/sfeb-ggd070314.php|url-status=live}}</ref> The [[hoof|hooves]] of large male giraffes reach {{cvt|31|x|23|cm}} in diameter.<ref name=Dagg2014/>{{rp|98}} The [[fetlock]] of the leg is low to the ground, allowing the hoof to better support the animal's weight. Giraffes lack [[dewclaw]]s and interdigital glands. While the pelvis is relatively short, the [[Ilium (bone)|ilium]] has stretched-out crests.<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, 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 movements of the head and neck provide balance and control momentum while galloping.<ref name=Kingdon1988/>{{rp|327–29}} The giraffe can reach a sprint speed of up to {{cvt|60|km/h}},<ref>{{Cite journal |last1=Garland |first1=T. |last2=J. |first2=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 |access-date=25 April 2010 |archive-date=20 November 2018 | archive-url=https://web.archive.org/web/20181120033719/https://biology.ucr.edu/people/faculty/Garland/GarlandJanis1993.pdf | url-status=dead}}</ref> and can sustain {{cvt|50|km/h}} for several kilometres.<ref>{{Cite book|author=Rafferty, J. P. |year=2011|title=Grazers (Britannica Guide to Predators and Prey) |publisher=[[Britannica Educational Publishing]] |page=194 |isbn=978-1-61530-336-6 |url=https://archive.org/details/grazers0000raff/page/194}}</ref> 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 |author1=Henderson, D. M. |author2=Naish, D. |year=2010 |title=Predicting the buoyancy, equilibrium and potential swimming ability of giraffes by computational analysis |journal=[[Journal of Theoretical Biology]] |volume=265 |issue=2 |pages=151–59 |pmid=20385144 |bibcode=2010JThBi.265..151H}}</ref> although they might be able to float.<ref name=Naish>{{cite journal |last=Naish |first=D. |author-link=Darren Naish |date=2011 |title=Will it Float? |periodical=[[Scientific American]] |volume=304 |issue=1 |page=22 |url=http://www.scientificamerican.com/article.cfm?id=will-it-float |doi=10.1038/scientificamerican0111-22 |bibcode=2011SciAm.304a..22N |access-date=30 December 2010 | archive-date=4 December 2013 |archive-url=https://web.archive.org/web/20131204212753/http://www.scientificamerican.com/article.cfm?id=will-it-float |url-status=live}}</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 water's surface.<ref name="swim"/>
[[File:Juvenile Giraffe - walking - Malawi - 2018 Aug.webm|thumb|right|A juvenile giraffe walking in Malawi]]
A giraffe rests by lying with its body on top of its folded legs.<ref name=Kingdon1988/>{{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 front knees and positions its backside on top of its hindlegs. It then pulls the backside upwards, and the front legs stand straight up again. At each stage, the animal swings its head for balance.<ref name=Dagg2014/>{{rp|67}} If the giraffe wants to reach down to drink, it either spreads its front legs or bends its knees.<ref name=estes/> Studies in captivity found the giraffe sleeps intermittently around 4.6 hours per day, mostly at night. It usually sleeps lying down; however, standing sleeps have been recorded, particularly in older individuals. Intermittent short "deep sleep" phases while lying are characterised 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 |last1=Tobler |first1=I. |last2=Schwierin |first2=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 |pmid=8795798|s2cid=34605791 |doi-access=free}}</ref>

===Internal systems===
[[File:GiraffaRecurrEn.svg|thumb|right|alt=Sketch of the path of the recurrent laryngeal nerve in giraffe|Scheme of path of the recurrent laryngeal nerve in giraffe]]

In mammals, the left [[recurrent laryngeal nerve]] is longer than the right; in the giraffe, it is over {{cvt|30|cm}} 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=251–256 |doi=10.4202/app.2011.0019|s2cid=43447891 |doi-access=free |archive-date=29 October 2013 |url-status=live |url=http://www.app.pan.pl/archive/published/app57/app20110019.pdf |archive-url=https://web.archive.org/web/20131029184627/http://www.app.pan.pl/archive/published/app57/app20110019.pdf}}</ref> the left nerve is over {{cvt|2|m}} 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=978-0-521-45321-9}}</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 {{cvt|5|m}} in the largest giraffes.<ref name=Wedel/> Despite its long neck and large skull, the [[brain]] of the giraffe is typical for an ungulate.<ref>{{cite journal |author1=Graïc, J.-M.|author2=Peruffo, A. |author3=Ballarin, C.|author4=Cozzi, B. |year=2017|title=The brain of the giraffe (''Giraffa camelopardalis''): surface configuration, encephalization quotient, and analysis of the existing literature|journal=The Anatomical Record |volume=300 |issue=8 |pages=1502–1511 |doi=10.1002/ar.23593 |pmid=28346748 |s2cid=3634656|doi-access=free}}</ref> Evaporative heat loss in the nasal passages keep the giraffe's brain cool.<ref name=Mitchell2004/> The shape of the skeleton gives the giraffe a small [[lung]] volume relative to its mass. Its long neck gives it a large amount of [[Dead space (physiology)|dead space]], though this is limited by its narrow windpipe. The giraffe also has a high [[tidal volume]], so the balance of dead space and tidal volume is much the same as other mammals. The animal can still provide enough oxygen for its tissues, and it can increase its [[Breathing|respiratory]] rate and oxygen diffusion when running.<ref name=SkinnerJD2011>{{Cite journal |author1=Skinner, J. D.|author2= Mitchell, G.|year= 2011|title=Lung volumes in giraffes, ''Giraffa camelopardalis'' |journal=Comparative Biochemistry and Physiology A |volume=158 |issue=1 |pages=72–78 |doi=10.1016/j.cbpa.2010.09.003 |pmid=20837156 |url=http://137.215.9.22/bitstream/handle/2263/16472/Mitchell_Lung(2011).PDF?sequence=1 |hdl=2263/16472|hdl-access= free|access-date= 27 November 2011|archive-date=20 November 2018 |url-status=live |archive-url=https://web.archive.org/web/20181120033132/https://137.215.9.22/bitstream/handle/2263/16472/Mitchell_Lung(2011).PDF?sequence=1}}</ref>
[[File:Flickr - Rainbirder - Reticulated Giraffe drinking.jpg|thumb|left|[[Reticulated giraffe]] bending down to drink in Kenya. The circulatory system is adapted to deal with blood flow rushing down its neck.|alt=Photograph of a giraffe bending down to drink]]
The giraffe's [[circulatory system]] has several adaptations to compensate for its great height.<ref name=Holmes>{{cite magazine |last1=Holmes |first1=B. |title=Heads up! The cardiovascular secrets of giraffes |magazine=Knowable Magazine |date=2021 |doi=10.1146/knowable-051821-2 |s2cid=236354545 |doi-access=free |url=https://knowablemagazine.org/article/living-world/2021/heads-up-cardiovascular-secrets-giraffes |access-date=1 August 2022 |archive-date=6 July 2022 |archive-url=https://web.archive.org/web/20220706111325/https://knowablemagazine.org/article/living-world/2021/heads-up-cardiovascular-secrets-giraffes |url-status=live}}</ref> Its {{cvt|25|lb|kg|order=flip}} and {{cvt|2|ft|cm|order=flip|-1}} [[heart]] must generate approximately double the blood pressure required for a human to maintain blood flow to the brain. As such, the wall of the heart can be as thick as {{cvt|7.5|cm}}.<ref name="Prothero 2003"/> Giraffes have relatively high heart rates for their size, at 150 beats per minute.<ref name=anatomy/>{{rp|76}} When the animal lowers its head, the blood rushes down fairly unopposed and a [[rete mirabile]] in the upper neck, with its large [[Cross section (geometry)|cross-sectional]] area, prevents excess blood flow to the brain. When it raises again, the blood vessels constrict and push blood into the brain so the animal does not faint.<ref>{{cite journal|author1=Mitchell, G. |author2=Skinner, J. D. |year=1993|title=How giraffe adapt to their extraordinary shape |journal=[[Transactions of the Royal Society of South Africa]]|volume=48|issue=2 |pages=207–218 |doi=10.1080/00359199309520271|bibcode=1993TRSSA..48..207M }}</ref> The [[jugular vein]]s 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 |author1=Mitchell, G.|author2=van Sittert, S. J.|author3=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=175–180 |url=http://137.215.9.22/bitstream/handle/2263/13994/Mitchell_Structure(2009).pdf?sequence=1 |year=2009 |hdl=2263/13994 |s2cid=55201969 |hdl-access=free|access-date=21 November 2011|archive-date=20 November 2018|archive-url=https://web.archive.org/web/20181120033146/https://137.215.9.22/bitstream/handle/2263/13994/Mitchell_Structure(2009).pdf?sequence=1|url-status=live}}</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 strong enough 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 [[Ruminant#Digestive system of ruminants|four-chambered stomachs]], which are adapted to their specialized diet.<ref name=Dagg1971/> The [[intestine]]s of an adult giraffe measure more than {{cvt|70|m}} in length and have a relatively small ratio of [[small intestine|small]] to [[large intestine]].<ref name="PerezEtAl2009">{{cite journal |author1=Pérez, W. |author2=Lima, M. |author3=Clauss, M. |year=2009 |title=Gross anatomy of the intestine in the giraffe (''Giraffa camelopardalis'') |url=https://www.zora.uzh.ch/id/eprint/24084/5/P%C3%A9rez_giraffe_intestine_AHE_revised-1.pdf |archive-url=https://web.archive.org/web/20180722150740/http://www.zora.uzh.ch/id/eprint/24084/5/P%C3%A9rez_giraffe_intestine_AHE_revised-1.pdf |archive-date=22 July 2018 |url-status=live |journal=Anatomia, Histologia, Embryologia |volume=38 |issue=6 |pages=432–435 |pmid=19681830 |doi=10.1111/j.1439-0264.2009.00965.x|s2cid=28390695}}</ref> The giraffe has a small, compact liver.<ref name=anatomy/>{{rp|76}} In fetuses there may be a small [[gallbladder]] that vanishes 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, C. K. |author2=Gilloteaux, J. |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=571–579 |year=1997 |doi=10.1002/(SICI)1097-0029(19970915)38:6<571::AID-JEMT3>3.0.CO;2-I |pmid=9330347 |s2cid=20040338}}</ref>