Editing Chimpanzee (section)

==Characteristics==
[[File:Naturales IMG 1851.jpg|thumb|Skeleton]]
Adult chimpanzees have an average standing height of {{cvt|150|cm|ftin}}.<ref>{{Cite journal |year=2010 |last=Braccini |first=E. |title=Bipedal tool use strengthens chimpanzee hand preferences|journal=Journal of Human Evolution |volume=58 |issue=3 |pages=234–241 |doi=10.1016/j.jhevol.2009.11.008 |pmc=4675323 |pmid=20089294|bibcode=2010JHumE..58..234B }}</ref> Wild adult males weigh between {{cvt|40|and|70|kg}},<ref>{{Cite journal |year=1994 |last=Levi |first=M. |title=Inhibition of endotoxin-induced activation of coagulation and fibrinolysis by pentoxifylline or by a monoclonal anti-tissue factor antibody in chimpanzees. |journal=The Journal of Clinical Investigation |volume=93 |issue=1 |pages=114–120 |doi=10.1172/JCI116934 |pmid=8282778 |pmc=293743 |doi-access=free}}</ref><ref>{{Cite journal |year=1993 |last=Lewis |first=J. C. M. |title=Medetomidine-ketamine anaesthesia in the chimpanzee (''Pan troglodytes'') |journal=Journal of Veterinary Anaesthesia |volume=20 |pages=18–20 |doi=10.1111/j.1467-2995.1993.tb00103.x}}</ref><ref>{{Cite journal |year=1997 |last1=Smith |first1=R. J. |last2=Jungers |first2=W. L. |title=Body mass in comparative primatology |journal=Journal of Human Evolution |volume=32 |issue=6 |pages=523–559 |doi=10.1006/jhev.1996.0122 |pmid=9210017|bibcode=1997JHumE..32..523S }}</ref> and females weigh between {{cvt|27|and|50|kg}}.<ref name=":0">{{Cite book |url=https://books.google.com/books?id=q_4yCppoH8MC&q=chimps+weigh&pg=PA17 |title=Jane Goodall: Primatologist and Animal Activist |last=Jankowski |first=C. |publisher=Compass Point Books |year=2009 |isbn=978-0-7565-4054-8 |location=Mankato, MN, US |pages=14 |oclc=244481732}}</ref> In exceptional cases, certain individuals may considerably exceed these measurements, standing over {{cvt|168|cm|ftin|0}} on two legs and weighing up to {{cvt|136|kg}} in captivity.{{efn|One captive male, "Kermit", attained a height of {{cvt|168|cm|ftin|0}} and a body weight of {{cvt|82|kg}} when he was 11 years old.<ref>{{cite news |url=https://osupublicationarchives.osu.edu/?a=d&d=LTN19910404-01.2.30&e=-------en-20--1--txt-txIN------- |title=Researchers treat chimps like children |access-date=2 October 2020 |first=R. L. |last=Gedert |publisher=[[The Lantern]] |page=9 |date=4 April 1991 |archive-date=21 April 2022 |archive-url=https://web.archive.org/web/20220421233333/https://osupublicationarchives.osu.edu/?a=d&d=LTN19910404-01.2.30&e=-------en-20--1--txt-txIN------- |url-status=live }}</ref> As a fully grown adult, he weighed almost {{cvt|136|kg}}.<ref>{{cite news |last1=Taylor |first1=H. |last2=Cropper |first2=J. |url=https://www.thelantern.com/2006/03/recounting-dead-osu-chimps-last-day/ |title=Recounting dead OSU chimp's last day |publisher=[[The Lantern]] |date=6 March 2006 |access-date=21 December 2020 |archive-date=11 June 2021 |archive-url=https://web.archive.org/web/20210611150840/https://www.thelantern.com/2006/03/recounting-dead-osu-chimps-last-day/ |url-status=live }}</ref>}}

The chimpanzee is more robustly built than the bonobo but less than the [[gorilla]]. The arms of a chimpanzee are longer than its legs and can reach below the knees. The hands have long fingers with short thumbs and flat fingernails. The feet are adapted for grasping, and the big toe is [[Thumb#Opposition and apposition|opposable]]. The pelvis is long with an extended [[Ilium (bone)|ilium]]. A chimpanzee's head is rounded with a prominent and [[prognathous]] face and a pronounced [[brow ridge]]. It has forward-facing eyes, a small nose, rounded non-lobed ears and a long mobile upper lip. Additionally, adult males have sharp canine teeth. Like all great apes, it has a [[dental formula]] of {{DentalFormula|upper=2.1.2.3|lower=2.1.2.3}}, that is, two [[incisors]], one [[Canine tooth|canine]], two [[premolars]], and three [[Molar (tooth)|molars]] on both halves of each jaw.  Chimpanzees lack the prominent [[sagittal crest]] and associated head and neck musculature of gorillas.<ref name="Jones_etal.1996"/><ref name="Estes">{{cite book |last=Estes |first=R. |title=The Behavior Guide to African Mammals |url=https://archive.org/details/isbn_0520080858 |url-access=registration |pages=[https://archive.org/details/isbn_0520080858/page/545 545–557] |year=1991 |publisher=University of California Press |isbn=978-0-520-08085-0}}</ref>
[[File:Chimp and human hands.jpg|thumb|right|Chimpanzee hand (left) compared to human hand]]
Chimpanzee bodies are covered by coarse hair, except for the face, fingers, toes, palms of the hands, and soles of the feet. Chimpanzees lose more hair as they age and develop bald spots. The hair of a chimpanzee is typically black but can be brown or ginger. As they get older, white or grey patches may appear, particularly on the chin and lower region.<ref name="Jones_etal.1996"/><ref name="Estes"/> Chimpanzee skin that is covered with body hair is white, while exposed areas vary: white which ages into a dark muddy colour in eastern chimpanzees, freckled on white which ages to a heavily mottled muddy colour in central chimpanzees, and black with a butterfly-shaped white mask that darkens with age in western chimpanzees.<ref name="Post Szabó Keeling 1975">{{cite journal |last1=Post |first1=Peter W. |last2=Szabó |first2=George |last3=Keeling |first3=M. E. |year=1975 |title=A quantitative and morphological study of the pigmentary system of the chimpanzee with the light and electron microscope |journal=American Journal of Physical Anthropology |volume=43 |issue=3 |pages=435–443 |doi=10.1002/ajpa.1330430325 |pmid=1211438 |issn=0002-9483}}</ref><ref name="Napier Napier 1967">{{cite book |last1=Napier |first1=John Russell |title=A Handbook of Living Primates: Morphology, Ecology and Behaviour of Nonhuman Primates |last2=Napier |first2=Prue H. |date=1967 |publisher=Acad. Press |isbn=978-0-12-513850-5 |publication-place=London}}</ref> Facial pigmentation increases with age and exposure to ultraviolet light. Females develop swelling pink skin when in oestrus.<ref name="Jones_etal.1996"/><ref name="Estes"/> Like bonobos, male chimpanzees have a long filiform [[penis]] with a small [[baculum]], but without a [[Glans penis|glans]].<ref>{{Cite book |last=Dixson |first=Alan F. |url=https://books.google.com/books?id=x4hNEAAAQBAJ&pg=PA68 |title=Sexual Selection and the Origins of Human Mating Systems |date=2009-05-14 |publisher=Oxford University Press |isbn=978-0-19-955943-5 |language=en}}</ref>

Chimpanzees are adapted for both [[Arboreal locomotion|arboreal]] and [[terrestrial locomotion]]. Arboreal locomotion consists of vertical climbing and [[brachiation]].<ref>{{cite journal |last=Hun |first=K. D. |year=1991 |title=Mechanical implications of chimpanzee positional behavior |journal=American Journal of Physical Anthropology |volume=86 |issue=4 |pages=521–536 |doi=10.1002/ajpa.1330860408 |pmid=1776659}}</ref><ref>{{cite journal |last1=Pontzer |first1=H. |last2=Wrangham |first2=R. W. |author2-link=Richard Wrangham |year=2004 |title=Climbing and the daily energy cost of locomotion in wild chimpanzees: implications for hominoid locomotor evolution |journal=Journal of Human Evolution |volume=46 |issue=3 |pages=315–333 |doi=10.1016/j.jhevol.2003.12.006 |pmid=14984786|bibcode=2004JHumE..46..315P }}</ref> On the ground, chimpanzees move both quadrupedally and bipedally. These movements appear to have similar energy costs.<ref>{{cite journal |last1=Pontzer |first1=H. |last2=Raichlen |first2=D. A. |last3=Rodman |first3=P. S. |year=2014 |title=Bipedal and quadrupedal locomotion in chimpanzees |journal=Journal of Human Evolution |volume=66 |pages=64–82 |doi=10.1016/j.jhevol.2013.10.002 |pmid=24315239|bibcode=2014JHumE..66...64P }}</ref> As with bonobos and gorillas, chimpanzees move quadrupedally by [[knuckle-walking]], which probably evolved independently in ''Pan'' and ''Gorilla''.<ref>{{cite journal |last1=Kivell |first1=T. L. |last2=Schimtt |first2=D. |year=2009 |title=Independent evolution of knuckle-walking in African apes shows that humans did not evolve from a knuckle-walking ancestor |journal=Proceedings of the National Academy of Sciences |volume=106 |issue=34 |pages=14241–14246 |doi=10.1073/pnas.0901280106 |pmid=19667206 |pmc=2732797 |bibcode=2009PNAS..10614241K |doi-access=free}}</ref> Their muscles are 50% stronger per weight than those of humans due to higher content of [[Skeletal muscle#Twitch speed|fast twitch muscle fibres]], one of the chimpanzee's adaptations for climbing and swinging.<ref>{{cite journal |last1=O'Neill |first1=M. C. |last2=Umberger |first2=B. R. |last3=Holowka |first3=N. B. |last4=Larson |first4=S. G. |last5=Reiser |first5=P. J. |year=2017 |title=Chimpanzee super strength and human skeletal muscle evolution |journal=Proceedings of the National Academy of Sciences |volume=114 |issue=28 |pages=7343–7348 |doi=10.1073/pnas.1619071114 |pmid=28652350 |pmc=5514706 |bibcode=2017PNAS..114.7343O |doi-access=free}}</ref> According to Japan's [[Asahiyama Zoo]], the grip strength of an adult chimpanzee is estimated to be {{cvt|200|kg}},<ref>{{cite web |url=https://www.city.asahikawa.hokkaido.jp/asahiyamazoo/zuroku/africa/d056965.html |title=チンパンジー |date=18 June 2016 |trans-title=Chimpanzee |publisher=[[Asahiyama Zoo]] |language=Japanese |access-date=15 March 2021 |archive-date=18 May 2021 |archive-url=https://web.archive.org/web/20210518143402/https://www.city.asahikawa.hokkaido.jp/asahiyamazoo/zuroku/africa/d056965.html |url-status=live }}</ref> while other sources claim figures of up to {{cvt|330|kg}}.{{efn|According to A. S. Vanesyan's "Anthropology" (2015), a study by "Vorden" (probably 'Worden' or 'Warden') reported that a {{cvt|54|kg}} male chimpanzee squeezed {{cvt|330|kg}} on a dynamometer, while an angry female squeezed {{cvt|504|kg}} with both hands. Of the hundreds of human students who also participated in the experiment, only one could squeeze more than {{cvt|200|kg}} with both hands.<ref>{{cite book |last1=Ванесян |first1=A. |title=Антропология |date=2015 |publisher=Directmedia |isbn= 9785447539337 |page=113}}</ref> The source is said to be "Jan Dembowskiy, ''The Psychology of Monkeys''."<ref>{{Cite web |url=https://antropogenez.ru/quote/614/ |title=Где ты, шимпанзиный гений? Об интеллектуальных и физических возможностях шимпанзе |trans-title=Where are you, chimpanzee genius? About the intellectual and physical capabilities of chimpanzees |website=[[antropogenez.ru]] |language=Russian |access-date=27 August 2021 |archive-date=23 October 2021 |archive-url=https://web.archive.org/web/20211023004556/https://antropogenez.ru/quote/614/ |url-status=live }}</ref> This study is listed in: {{cite book | title=The Chimpanzee: A Topical Bibliography |edition=2nd |last=Dembowski |first=J. |chapter=Psychology of Monkeys |location=Warsaw |publisher=Ksrazka |date=1946 |url=https://apps.dtic.mil/dtic/tr/fulltext/u2/748249.pdf |pages=359 |access-date=19 March 2021 |url-status=dead |archive-url=https://web.archive.org/web/20210720184946/https://apps.dtic.mil/dtic/tr/fulltext/u2/748249.pdf |archive-date=20 July 2021}}}}