Gorilla#Behavior

{{Short description|Genus of large African apes}}

{{other uses}}

{{distinguish |Guerrilla}}

{{pp-move}}

{{Use dmy dates |date=October 2020}}

{{Automatic taxobox

|italic_title = no

|image = Gorille des plaines de l'ouest à l'Espace Zoologique.jpg

|image_caption = Western gorilla
(Gorilla gorilla)

|taxon = Gorilla

|authority = I. Geoffroy, 1852

|type_species = Troglodytes gorilla

|type_species_authority = Savage, 1847

|subdivision_ranks = Species

|subdivision =

Gorilla gorilla

Gorilla beringei

|range_map = Distibuci%C3%B3n_gorilla.png

|range_map_caption = Distribution of gorillas

|synonyms =

  • Pseudogorilla Elliot, 1913

}}

Gorillas are primarily herbivorous{{Cite web |date=2023-08-21 |title=Top 10 facts about mountain gorillas {{!}} WWF |url=https://www.wwf.org.uk/learn/fascinating-facts/gorillas |access-date=2025-05-16 |website=www.wwf.org.uk |language=en}}, terrestrial great apes that inhabit the tropical forests of equatorial Africa. The genus Gorilla is divided into two species: the eastern gorilla and the western gorilla, and either four or five subspecies. The DNA of gorillas is highly similar to that of humans, from 96 to 99% depending on what is included, and they are the next closest living relatives to humans after the chimpanzees.

Gorillas are the largest living primates, reaching heights between {{cvt|1.25 and 1.8|m}}, weights between {{cvt|100 and 270|kg}}, and arm spans up to {{cvt|2.6|m}}, depending on species and sex. They tend to live in troops, with the leader being called a silverback. The eastern gorilla is distinguished from the western by darker fur colour and some other minor morphological differences. Gorillas tend to live 35–40 years in the wild.

Gorillas' natural habitats cover tropical or subtropical forest in Sub-Saharan Africa. Although their range covers a small percentage of Sub-Saharan Africa, gorillas cover a wide range of elevations. The mountain gorilla inhabits the Albertine Rift montane cloud forests of the Virunga Volcanoes, ranging in altitude from {{cvt|2200 to 4300|m}}. Lowland gorillas live in dense forests and lowland swamps and marshes as low as sea level, with western lowland gorillas living in Central West African countries and eastern lowland gorillas living in the Democratic Republic of the Congo near its border with Rwanda.

There are thought to be around 316,000 western gorillas in the wild, and 5,000 eastern gorillas. Both species are classified as Critically Endangered by the IUCN; all subspecies are classified as Critically Endangered with the exception of the mountain gorilla, which is classified as Endangered. There are many threats to their survival, such as poaching, habitat destruction, and disease, which threaten the survival of the species. However, conservation efforts have been successful in some areas where they live.

History and etymology

{{see also |Hanno the Navigator#Gorillai}}

The word gorilla comes from the history of Hanno the Navigator ({{abbr |c. |circa}} 500 BC), a Carthaginian explorer on an expedition to the west African coast to the area that later became Sierra Leone.{{Cite book |author=Müller, C. |title=Geographi graeci minores |year=1855–1861 |pages=1.1–14: text and trans. Ed. J. Blomqvist (1979)}}{{cite journal |first=P. E. H. |last=Hair |title=The Periplus of Hanno in the history and historiography of Black Africa |journal=History in Africa |volume=14 |year=1987 |pages=43–66 |doi=10.2307/3171832 |jstor=3171832 |s2cid=162671887}} Members of the expedition encountered "savage people, the greater part of whom were women, whose bodies were hairy, and whom our interpreters called Gorillae".{{cite book | chapter=The Voyage of Hanno, commander of the Carthaginians, round the parts of Lilxya beyond the Pillars of Hercules, which he deposited in the temple of Saturn |editor= A.H.L. Heeren| title=Historical researches into the Politics, Intercourse and Trade of the Cathaginians, Ethiopians, and Egyptians| place= Oxford| publisher =D. A. Talboys|date= 1832|pages= 492–501| chapter-url=http://www.shsu.edu/~his_ncp/Hanno.html |archive-url=https://web.archive.org/web/20170314000332/http://www.shsu.edu/~his_ncp/Hanno.html |archive-date=14 March 2017}}{{cite journal |first=M. F. A. |last=Montagu |author-link=Ashley Montagu |title=Knowledge of the Ape in Antiquity |journal=Isis |volume=32 |issue=1 |year=1940 |pages=87–102 |doi=10.1086/347644 |s2cid=143874276}} It is unknown whether what the explorers encountered were what we now call gorillas, another species of ape or monkeys, or humans. Skins of gorillai women, brought back by Hanno, are reputed to have been kept at Carthage until Rome destroyed the city 350 years later at the end of the Punic Wars, 146 BC.

In 1625 Andrew Battel mentioned the existence of the animal, under the name Pongo:

{{quote|This Pongo is in all proportion like a man, but... he is more like a Giant in stature, than a man: for he is very tall, [and] hath a man's face, hollow-eyed, with long haire vpon his browes. His face and eares are without haire, and his hands also. His bodie is full of haire, but not very thicke, and it is a dunnish colour. . . Hee goeth alwaies vpon his legs, and carrieth his hands clasped on the nape of his necke, when he goeth upon the ground... They goe many together, and kill many Negroes that trauaile in the Woods . . . Those Pongos are neuer taken aliue, because they are so strong, that ten men cannot hold one of them... |Andrew Battel, 1625{{cite web |title=Fantastic Creatures, part 2 |url=https://www.pbs.org/wgbh/nova/lochness/creatures2.html | website = NOVA Online | date= November 2000 |publisher=Public Broadcasting Service |access-date=30 May 2024}}}}

A century and a half after Battel's story was published, one writer called Radermacher wrote that "the large species, described by Buffon and other authors as of the size of a man, is held by many to be a Chimera."{{cite book |last1=Heuvelmans |first1=Bernard |title=On The Track Of Unknown Animals |date=10 July 2014 |publisher=Routledge |isbn=978-1-317-84812-7 |page=26 |url=https://books.google.com/books?id=u64ABAAAQBAJ&dq=%22the+large+species,+described+by+Buffon+and+other+authors+as+of+the+size+of+a+man,+is+held+by+many+to+be+a+Chimera.%22&pg=PA26 |access-date=2 February 2025 |language=en}}

The American physician and missionary Thomas Staughton Savage and naturalist Jeffries Wyman first described the western gorilla in 1847 from specimens obtained in Liberia.{{Cite journal |doi=10.1002/evan.20203 |title=Discovering gorilla |journal=Evolutionary Anthropology: Issues, News, and Reviews |volume=18 |issue=2 |pages=55–61 |year=2009 |last1=Conniff |first1=R. |s2cid=221732306}} They called it Troglodytes gorilla, using the then-current name of the chimpanzee genus. The species name was derived {{ety |grc |Γόριλλαι (gorillai) |tribe of hairy women}},{{cite web |url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3D*go%2Frillai |archive-url=https://web.archive.org/web/20110606090702/http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=*go%2Frillai |archive-date=6 June 2011 |first1=H. G. |last1=Liddell |first2=R. |last2=Scott |work=A Greek-English lexicon |title=Γόριλλαι |publisher=Perseus Digital Library}} as described by Hanno.

Evolution and classification

The closest relatives of gorillas are the other two Homininae genera, chimpanzees and humans, all of them having diverged from a common ancestor about 7 million years ago.{{Cite journal |last1=Glazko |first1=G. V. |last2=Nei |first2=Masatoshi |author2-link=Masatoshi Nei |title=Estimation of divergence times for major lineages of primate species |journal=Molecular Biology and Evolution |volume=20 |issue=3 |pages=424–434 |date=March 2003 |pmid=12644563 |doi=10.1093/molbev/msg050 |doi-access=free}} Human gene sequences differ only 1.6% on average from the sequences of corresponding gorilla genes, but there is further difference in how many copies each gene has.{{Cite journal |last1=Goidts |first1=V. |title=Identification of large-scale human-specific copy number differences by inter-species array comparative genomic hybridization |journal=Human Genetics |volume=119 |issue=1–2 |pages=185–198 |date=March 2006 |pmid=16395594 |doi=10.1007/s00439-005-0130-9 |last2=Armengol |first2=L. |last3=Schempp |first3=W. |display-authors=3 |last4=Conroy |first4=Jeffrey |last5=Nowak |first5=Norma |last6=Müller |first6=Stefan |last7=Cooper |first7=David N. |last8=Estivill |first8=Xavier |last9=Enard |first9=Wolfgang |s2cid=32184430}}

class="wikitable" style="margin: 1em auto 1em auto" border="1" width="350pt"
scope=col |Phylogeny of superfamily Hominoidea{{Cite journal |last1=Israfil |first1=H. |last2=Zehr |first2=S. M. |last3=Mootnick |first3=A. R. |last4=Ruvolo |first4=M. |last5=Steiper |first5=M. E. |title=Unresolved molecular phylogenies of gibbons and siamangs (Family: Hylobatidae) based on mitochondrial, Y-linked, and X-linked loci indicate a rapid Miocene radiation or sudden vicariance event |doi=10.1016/j.ympev.2010.11.005 |journal=Molecular Phylogenetics and Evolution |volume=58 |issue=3 |pages=447–455 |year=2011 |pmid=21074627 |pmc=3046308 |bibcode=2011MolPE..58..447I |url=http://www.gibboncenter.org/publications/MolecularPhylogeneticsIsrafil_etal_2011_MPE.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120510084118/http://www.gibboncenter.org/publications/MolecularPhylogeneticsIsrafil_etal_2011_MPE.pdf |archive-date=10 May 2012}}{{rp |at=Fig. 4}}
{{Clade

|label1=Hominoidea

|1={{Clade

|1=gibbons (family Hylobatidae)

|2={{Clade

|1=orangutans (genus Pongo)

|2={{Clade

|1=gorillas (genus Gorilla)

|2={{Clade

|1=humans (genus Homo)

|2=chimpanzees (genus Pan)

}}

}}

}}

}}

}}

Until recently, gorillas were considered to be a single species, with three subspecies: the western lowland gorilla, the eastern lowland gorilla and the mountain gorilla.{{Cite book |first=C. |last=Groves |author-link=Colin Groves |year=2002 |chapter-url=http://arts.anu.edu.au/grovco/Gorilla%20Biology.pdf |chapter=A history of gorilla taxonomy |title=Gorilla biology: A multidisciplinary perspective |editor1-first=A. B. |editor1-last=Taylor |editor2-first=M. L. |editor2-last=Goldsmith |publisher=Cambridge University Press |pages=15–34 |url-status=dead |archive-url=https://web.archive.org/web/20090326001207/http://arts.anu.edu.au/grovco/Gorilla%20Biology.pdf |archive-date=26 March 2009}}{{cite web |url=http://www.fathom.com/course/21701783/ |title=Mountain gorillas of the Virungas |access-date=11 September 2008 |last1=Stewart |first1=K. J. |first2=P. |last2=Sicotte |first3=M. M. |last3=Robbins |year=2001 |publisher=Fathom / Cambridge University Press |url-status=dead |archive-url=https://web.archive.org/web/20080921145524/http://www.fathom.com/course/21701783/ |archive-date=21 September 2008}} There is now agreement that there are two species, each with two subspecies.{{cite book |editor1-last=Mittermeier |editor1-first=R. A. |editor1-link=Russell A. Mittermeier |editor2-first=A. B. |editor2-last=Rylands |editor3-first=D. E. |editor3-last=Wilson |editor3-link=Don E. Wilson |title=Handbook of the Mammals of the World. Volume 3. Primates |publisher=Lynx Edicions |location=Barcelona |year=2013 |isbn=978-8496553897}} More recently, a third subspecies has been claimed to exist in one of the species. The separate species and subspecies developed from a single type of gorilla during the Ice Age, when their forest habitats shrank and became isolated from each other.{{Cite book |title=Songs of the gorilla nation |last=Prince-Hughes |first=D. |author-link=Dawn Prince-Hughes |year=1987 |publisher=Harmony |isbn= 978-1400050581 |page= [https://archive.org/details/songsofgorillana00prinrich/page/66 66] |url= https://archive.org/details/songsofgorillana00prinrich/page/66}} {{bsn|date=December 2024|reason=even if the thought-provoking autobiographical memoir "Songs of the Gorilla Nation: My journey through autism" happens to support somewhere all the claims cited to it (added by User:Gloriamarie in unbroken sequence beginning Special:Diff/373104341 in July 2010), we still probably need a real source for them. Also page 66 is a poem not even self-evidently about gorillas.}}{{Failed verification|date=September 2024}} Primatologists continue to explore the relationships between various gorilla populations. The species and subspecies listed here are the ones upon which most scientists agree.

{{Species table |no-note=y |genus=Gorilla |authority-name=Geoffroy |authority-year=1852 |species-count=two|narrow-percent=75}}

{{Species table/row

|name=Eastern gorilla |binomial=G. beringei

|image=File:Male_Gorilla_(181091305).jpg |image-size=180px |image-alt=Black gorilla

|authority-name=Matschie |authority-year=1903

|subspecies={{Collapsible list |expand=yes |title=Two subspecies |bullets=on

| G. b. beringei (Mountain gorilla)

| G. b. graueri (Eastern lowland gorilla)

}}

|range=Central Africa
{{maplink|frame=yes|plain=yes|frame-width=162|from=Eastern gorilla range.map}} |range-image= |range-image-size=180px

|size={{convert|160|–|196|cm|in|0|abbr=on}} long

|habitat=Forest

|hunting=Roots, leaves, stems, and pith, as well as bark, wood, flowers, fruit, fungi, galls, invertebrates, and gorilla dung

|iucn-status=CR |population=2,600

|direction={{decrease|Population declining}}

}}

{{Species table/row

|name=Western gorilla |binomial=G. gorilla

|image=File:Male_gorilla_in_SF_zoo.jpg |image-size=160px |image-alt=Black gorilla

|authority-name=Savage |authority-year=1847 |authority-not-original=yes

|subspecies={{Collapsible list |expand=yes |title=Two subspecies |bullets=on

| G. g. diehli (Cross River gorilla)

| G. g. gorilla (Western lowland gorilla)

}}

|range=Western Africa
{{maplink|frame=yes|plain=yes|frame-width=162|from=Western gorilla range.map}} |range-image= |range-image-size=135px

|size={{convert|130|–|185|cm|in|0|abbr=on}} long

|habitat=Forest

|hunting=Leaves, berries, ferns, and fibrous bark

|iucn-status=CR |population=Unknown

|direction={{decrease|Population declining}}

}}

{{Species table/end}}

The proposed third subspecies of Gorilla beringei, which has not yet received a trinomen, is the Bwindi population of the mountain gorilla, sometimes called the Bwindi gorilla.

Some variations that distinguish the classifications of gorilla include varying density, size, hair colour, length, culture, and facial widths. Population genetics of the lowland gorillas suggest that the western and eastern lowland populations diverged around 261 thousand years ago.{{cite journal |doi=10.1093/molbev/msu394 |pmid=25534031 |pmc=4327160 |title=Inference of gorilla demographic and selective history from whole-genome sequence data |journal=Molecular Biology and Evolution |volume=32 |issue=3 |pages=600–612 |year=2015 |last1=McManus |first1=K. F. |last2=Kelley |first2=J. L. |last3=Song |first3=S.

|display-authors=3|last4=Veeramah |first4=Krishna R. |last5=Woerner |first5=August E. |last6=Stevison |first6=Laurie S. |last7=Ryder |first7=Oliver A. |last8=Ape Genome Project |first8=Great |last9=Kidd |first9=Jeffrey M. |last10=Wall |first10=Jeffrey D. |last11=Bustamante |first11=Carlos D. |last12=Hammer |first12=Michael F.}}

Characteristics

File:Gorilla Male perspective 5.jpg

Wild male gorillas weigh {{convert |136 |to |227 |kg |lb |-1 |abbr=on}}, while adult females weigh {{convert |68 |- |113 |kg |lb |-1 |abbr=on}}.{{Cite journal |year=2006 |last=Aryan |first=H. E. |title=Lumbar diskectomy in a human-habituated mountain gorilla (Gorilla beringei beringei) |journal=Clinical Neurology and Neurosurgery |volume=108 |issue=2 |pages=205–210 |doi=10.1016/j.clineuro.2004.12.011 |pmid=16412845 |s2cid=29723690}}{{cite book |last=Miller |first=Patricia |title=Gorillas |year=1997 |isbn=978-0919879898 |pages=64 |publisher=Weigl Educational Publishers |url=https://books.google.com/books?id=wSXgVKUYpvgC&pg=PA8 |url-status=live |archive-url=https://web.archive.org/web/20160510210603/https://books.google.com/books?id=wSXgVKUYpvgC&pg=PA8 |archive-date=10 May 2016}} Adult males are {{convert |1.4 |to |1.8 |m |ftin |abbr=on}} tall, with an arm span that stretches from {{convert |2.3 |to |2.6 |m |ftin |abbr=on}}. Female gorillas are shorter at {{convert |1.25 |to |1.5 |m |ftin |abbr=on}}, with smaller arm spans.{{Cite journal |pmid=736111 |year=1978 |last1=Wood |first1=B. A. |title=Relationship between body size and long bone lengths in Pan and Gorilla |journal=American Journal of Physical Anthropology |volume=50 |issue=1 |pages=23–25 |doi=10.1002/ajpa.1330500104}}{{Cite journal |doi=10.1002/ajp.1350360104 |pmid=31924084 |title=Ontogeny and the evolution of adult body size dimorphism in apes |journal=American Journal of Primatology |volume=36 |issue=1 |pages=37–60 |year=1995 |last1=Leigh |first1=S. R. |last2=Shea |first2=B. T. |s2cid=85136825}}{{cite book |last=Tuttle |first=R. H. |title=Apes of the world: their social behavior, communication, mentality and ecology |year=1986 |publisher=William Andrew |isbn=978-0815511045 |url-access=registration |url=https://archive.org/details/apesofworldtheir0000tutt}} Colin Groves (1970) calculated the average weight of 42 wild adult male gorillas at 144 kg, while Smith and Jungers (1997) found the average weight of 19 wild adult male gorillas to be 169 kg.{{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}}{{Cite journal |last=Groves |first=C. P. |date=July 1970 |title=Population systematics of the gorilla |url=https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-7998.1970.tb04514.x |journal=Journal of Zoology |volume=161 |issue=3 |pages=287–300 |doi=10.1111/j.1469-7998.1970.tb04514.x |via=Onlinelibrary}} Adult male gorillas are known as silverbacks due to the characteristic silver hair on their backs reaching to the hips. The tallest wild gorilla recorded was a {{convert |1.95 |m |ftin |abbr=on}} silverback with an arm span of {{convert |2.7 |m |abbr=on}}, a chest of {{convert |1.98 |m |abbr=on}}, and a weight of {{convert |219 |kg |abbr=on}}, shot in Alimbongo, northern Kivu in May 1938. The heaviest wild gorilla recorded was a {{convert |1.83 |m |ftin |abbr=on}} silverback shot in Ambam, Cameroon, which weighed {{convert |267 |kg |lb |abbr=on}}.{{cite book |last=Wood |first=G. L. |title=The Guinness book of animal facts and feats |publisher=Sterling Publishing |year=1983 |isbn=978-0851122359 |url=https://archive.org/details/guinnessbookofan00wood}} The tallest gorilla in captivity was Gust, a western lowland gorilla that was captured as a baby in Belgian Congo and spent his life at Antwerp Zoo. He was {{convert |2.20|m |ftin |abbr=on}} tall. Males in captivity can be overweight and reach weights up to {{convert |310 |kg |lb |0 |abbr=on}}.

File:Gorilla gorilla & Gorilla beringei.jpg (Gorilla gorilla) and eastern gorilla (Gorilla beringei)]]

The eastern gorilla is more darkly coloured than the western gorilla, with the mountain gorilla being the darkest of all. The mountain gorilla also has the thickest hair. The western lowland gorilla can be brown or greyish with a reddish forehead. In addition, gorillas that live in lowland forest are more slender and agile than the more bulky mountain gorillas. The eastern gorilla also has a longer face and broader chest than the western gorilla.{{cite book |last=Rowe |first=N. |year=1996 |title=Pictorial guide to the living primates |location=East Hampton, NY |publisher=Pogonias Press}} Like humans, gorillas have individual fingerprints.{{cite web |title=Santa Barbara Zoo – western lowland gorilla |url=http://www.santabarbarazoo.org/showAnimals.asp?id=149 |publisher=Santa Barbara Zoo |access-date=10 October 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060928075121/http://www.santabarbarazoo.org/showAnimals.asp?id=149 |archive-date=28 September 2006}}{{cite web |url=http://nationalzoo.si.edu/Animals/Primates/Facts/FactSheets/Gorillas/default.cfm |title=Gorillas |archive-url=https://web.archive.org/web/20100601162521/http://nationalzoo.si.edu/Animals/Primates/Facts/FactSheets/Gorillas/default.cfm |archive-date=1 June 2010 |publisher=Smithsonian National Zoological Park}}

Their eye colour is dark brown, framed by a black ring around the iris. Gorilla facial structure is described as mandibular prognathism, that is, the mandible protrudes farther out than the maxilla. Adult males also have a prominent sagittal crest.

Gorillas move around by knuckle-walking, although they sometimes walk upright for short distances, typically while carrying food or in defensive situations. A 2018 study investigating the hand posture of 77 mountain gorillas at Bwindi Impenetrable National Park (8% of the population) found that knuckle walking was done only 60% of the time, and they also supported their weight on their fists, the backs of their hands/feet, and on their palms/soles (with the digits flexed). Such a range of hand postures was previously thought to have been used by only orangutans.{{Cite journal |doi=10.1002/ajpa.23404 |pmid=29344933 |title=Unexpected terrestrial hand posture diversity in wild mountain gorillas |journal=American Journal of Physical Anthropology |volume=166 |issue=1 |pages=84–94 |year=2018 |last1=Thompson |first1=N. E. |last2=Ostrofsky |first2=K. R. |last3=McFarlin |first3=S. C. |last4=Robbins |first4=M. M. |last5=Stoinski |first5=T. S. |last6=Almécija |first6=S. |doi-access=free}} Studies of gorilla handedness have yielded varying results, with some arguing for no preference for either hand, and others right-hand dominance for the general population.{{cite journal |first1=J. |last1=Fagot |first2=J. |last2=Vauclair |year=1988 |title=Handedness and bimanual coordination in the lowland gorilla |journal=Brain, Behavior and Evolution |volume=32 |issue=2 |pages=89–95 |doi=10.1159/000116536 |pmid=3179697}}

Studies have shown gorilla blood is not reactive to anti-A and anti-B monoclonal antibodies, which would, in humans, indicate type O blood. Due to novel sequences, though, it is different enough to not conform with the human ABO blood group system, into which the other great apes fit.{{Cite journal |last1=Gamble |first1=K. C. |last2=Moyse |first2=J. A. |last3=Lovstad |first3=J. N. |last4=Ober |first4=C. B. |last5=Thompson |first5=E. E. |title=Blood groups in the Species Survival Plan, European Endangered Species Program, and managed in situ populations of bonobo (Pan paniscus), common chimpanzee (Pan troglodytes), gorilla (Gorilla ssp.), and orangutan (Pongo pygmaeus ssp.) |doi=10.1002/zoo.20348 |journal=Zoo Biology |volume=30 |issue=4 |pages=427–444 |year=2011 |pmid=20853409 |pmc= 4258062 |url=http://www.orangutanssp.org/ga_blood_typing.pdf |access-date=5 January 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120120220734/http://www.orangutanssp.org/ga_blood_typing.pdf |archive-date=20 January 2012}}

A gorilla's lifespan is normally between 35 and 40 years, although zoo gorillas may live for 50 years or more in rare circumstances. At {{age in years and days|1957|1|1}}, Fatou is both the oldest living gorilla and oldest living female gorilla. The oldest male gorilla ever was Ozoum, who reached to the final age of 61 years, 24 days.{{Cite web |last=Jackson |first=Amanda |date=2022-01-26 |title=Ozzie, the world's oldest male gorilla, has died at Zoo Atlanta |url=https://www.cnn.com/2022/01/25/us/ozzie-oldest-gorilla-atlanta-zoo-dies-trnd/index.html |access-date=2022-01-26 |website=CNN}} The oldest living male gorilla is Guhonda, aged {{age in years and days|1971|1|1}}.

Distribution and habitat

File:Nshongi Gorilla Group-7, by Justin Norton.jpg

Gorillas have a patchy distribution. The range of the two species is separated by the Congo River and its tributaries. The western gorilla lives in west central Africa, while the eastern gorilla lives in east central Africa. Between the species, and even within the species, gorillas live in a variety of habitats and elevations. Gorilla habitat ranges from montane forest to swampland. Eastern gorillas inhabit montane and submontane forests between {{convert |650 |and |4000 |m |ft |abbr=on}} above sea level.{{cite book |last=Sarmiento |first=E. E. |year=2003 |chapter=Distribution, taxonomy, genetics, ecology, and causal links of gorilla survival: the need to develop practical knowledge for gorilla conservation |editor1-last=Taylor |editor1-first=A. B. |editor2-last=Goldsmith |editor2-first=M. L. |title=Gorilla Biology: A multidisciplinary perspective |location=Cambridge, UK |publisher=Cambridge University Press |pages=432–471 | doi= 10.1017/CBO9780511542558.020 |isbn=978-0-521-79281-3 }}

Mountain gorillas live in montane forests at the higher end of the elevation range, while eastern lowland gorillas live in submontane forests at the lower end. In addition, eastern lowland gorillas live in montane bamboo forests, as well as lowland forests ranging from {{convert |600 |– |3308 |m |ft |abbr=on}} in elevation.{{cite conference |last=Ilambu |first=O. |year=2001 |chapter=Ecology of eastern lowland gorilla: Is there enough scientific knowledge to mitigate conservation threats associated with extreme disturbances in its distribution range? |title=The Apes: Challenges for the 21st century |location=Brookfield, IL, USA |publisher=Chicago Zoological Society |pages=307–312 |isbn =9780913934289 }} Western gorillas live in both lowland swamp forests and montane forests, at elevations ranging from sea level to {{convert |1600 |m |ft |abbr=on}}. Western lowland gorillas live in swamp and lowland forests ranging up to {{convert |1600 |m |ft |abbr=on}}, and Cross River gorillas live in low-lying and submontane forests ranging from {{convert |150 |– |1600 |m |ft |abbr=on}}.

Ecology

=Diet and foraging=

File:Gorillas-moving.jpg

A gorilla's day is divided between rest periods and travel or feeding periods. Diets differ between and within species. Mountain gorillas mostly eat foliage, such as leaves, stems, pith, and shoots, while fruit makes up a very small part of their diets.{{sfn|McNeilage|2001|pp=265–292}} Mountain gorilla food is widely distributed and neither individuals nor groups have to compete with one another. Their home ranges vary from {{cvt|3 to 15|km2}}, and their movements range around {{cvt|500|m|mi}} or less on an average day.{{sfn|McNeilage|2001|pp=265–292}} Despite eating a few species in each habitat, mountain gorillas have flexible diets and can live in a variety of habitats.{{sfn|McNeilage|2001|pp=265–292}}

File:Gorilla gorilla08.jpg

Eastern lowland gorillas have more diverse diets, which vary seasonally. Leaves and pith are commonly eaten, but fruits can make up as much as 25% of their diets. Since fruit is less available, lowland gorillas must travel farther each day, and their home ranges vary from {{cvt|2.7 to 6.5|km2}}, with day ranges {{cvt|154–2280|m|mi}}. Eastern lowland gorillas will also eat insects, preferably ants.{{cite journal |last1=Yamagiwa |first1=J. |last2=Mwanza |first2=N. |last3=Yumoto |first3=T. |last4=Maruhashi |first4=T. |year=1994 |title=Seasonal change in the composition of the diet of eastern lowland gorillas |journal=Primates |volume= 35 |doi=10.1007/BF02381481 |pages=1–14 |s2cid=33021914}} Western lowland gorillas depend on fruits more than the others and they are more dispersed across their range.{{cite book |last=Tutin |first=C. G. |year=1996 |chapter=Ranging and social structure of lowland gorillas in the Lopé Reserve, Gabon |editor1-last=McGrew |editor1-first=W. C. |editor2-last=Marchant |editor2-first=L. F. |editor3-last=Nishida |editor3-first=T. |title=Great Ape Societies |location=Cambridge, UK |publisher=Cambridge University Press |pages=58–70}} They travel even farther than the other gorilla subspecies, at {{cvt|1105|m|mi}} per day on average, and have larger home ranges of {{cvt|7–14|km2}}. Western lowland gorillas have less access to terrestrial herbs, although they can access aquatic herbs in some areas. Termites and ants are also eaten.

Gorillas rarely drink water "because they consume succulent vegetation that is {{sic|comprised|hide=y| of}} almost half water as well as morning dew",{{cite web |url=http://www.seaworld.org/animal-info/info-books/gorilla/diet.htm |title=Gorillas – diet & eating habits |archive-url=https://web.archive.org/web/20110811113134/http://www.seaworld.org/animal-info/info-books/gorilla/diet.htm |archive-date=11 August 2011 |publisher=Seaworld |access-date= 27 September 2011}} although both mountain and lowland gorillas have been observed drinking.

= Nesting =

{{see also | Nest-building in primates#In hominid apes|label 1= Nest-building in primates § In gorillas}}

File:Gorilla nest.jpg

Gorillas construct nests for daytime and night use. Nests tend to be simple aggregations of branches and leaves about {{convert |2 |to |5 |ft |m |abbr=on}} in diameter and are constructed by individuals. Gorillas, unlike chimpanzees or orangutans, tend to sleep in nests on the ground. The young nest with their mothers, but construct nests after three years of age, initially close to those of their mothers.{{cite book |url=https://books.google.com/books?id=wSXgVKUYpvgC&pg=PA20 |title=Gorillas |last=Miller-Schroeder |first=P. |publisher=Weigl Educational Publishers Limited |year=1997 |isbn=978-0919879898 |page=20 |access-date=4 July 2011 |archive-url=https://web.archive.org/web/20140627144631/http://books.google.com/books?id=wSXgVKUYpvgC&pg=PA20 |archive-date=27 June 2014 |url-status=live}} Gorilla nests are distributed arbitrarily and use of tree species for site and construction appears to be opportunistic.{{cite book |last1=Marchant |first1=L. F. |last2=Nishida |first2=T. |title=Great ape societies |url=https://books.google.com/books?id=iGfjJ4lKb1IC&pg=PA226 |access-date=4 July 2011 |year=1996 |publisher=Cambridge University Press |isbn=978-0521555364 |pages=226–227 |url-status=live |archive-url=https://web.archive.org/web/20140627144319/http://books.google.com/books?id=iGfjJ4lKb1IC&pg=PA226 |archive-date=27 June 2014}} Nest-building by great apes is now considered to be not just animal architecture, but as an important instance of tool use.

Gorillas make a new nest to sleep on each day; even if remaining in the same place, they do not use the previous one. Usually, they are made an hour before dusk, to be ready to sleep when night falls. Gorillas sleep longer than humans, an average of 12 hours per day.{{Cite web |date=18 Oct 2019 |title=Gorilla Night Routines |url=https://gorillafund.org/uncategorized/gorilla-night-routines/ |access-date=8 Oct 2022 |website=Gorilla Fund}}

= Interspecies interactions =

One possible predator of gorillas is the leopard. Gorilla remains have been found in leopard scat, but this may be the result of scavenging.{{cite journal |last1=Fay |first1=J. M. |last2=Carroll |first2=R. |last3=Kerbis Peterhans |first3=J. C. |last4=Harris |first4=D. |year=1995 |url=http://www.catsg.org/catsglib/recordetail.php?recordid=5654 |title=Leopard attack on and consumption of gorillas in the Central African Republic |journal=Journal of Human Evolution |volume=29 |issue=1 |pages=93–99 |doi=10.1006/jhev.1995.1048 |bibcode=1995JHumE..29...93F |url-status=live |archive-url=https://web.archive.org/web/20120403130757/http://www.catsg.org/catsglib/recordetail.php?recordid=5654 |archive-date=3 April 2012}} When the group is attacked by humans, leopards, or other gorillas, an individual silverback will protect the group, even at the cost of his own life.{{cite web |url=http://www.awf.org/content/wildlife/detail/mountaingorilla |title=Wildlife: mountain gorilla |archive-url=https://web.archive.org/web/20120217164839/http://www.awf.org/content/wildlife/detail/mountaingorilla |archive-date=17 February 2012 |publisher=AWF |access-date=27 September 2011}} Gorillas do not appear to directly compete with chimpanzees in areas where they overlap. When fruit is abundant, gorilla and chimpanzee diets converge, but when fruit is scarce gorillas resort to vegetation.{{cite journal |last1=Tutin |first1=C. E. G. |last2=Fernandez |first2=M. |year=1993 |title=Composition of the diet of chimpanzees and comparisons with that of sympatric lowland gorillas in the Lopé reserve, Gabon |journal=American Journal of Primatology |volume=30 |issue=3 |pages=195–211 |doi=10.1002/ajp.1350300305 |pmid=31937009 |s2cid=84681736}} The two apes may also feed on different species, whether fruit or insects.{{cite journal |last1=Stanford |first1=C. B. |last2=Nkurunungi |first2=J. B. |year=2003 |title=Behavioral ecology of sympatric chimpanzees and gorillas in Bwindi Impenetrable National Park, Uganda: diet |journal=International Journal of Primatology |volume=24 |issue=4 |pages=901–918 |doi=10.1023/A:1024689008159 |s2cid=22587913}}{{cite journal |last1=Tutin |first1=C. E. G. |last2=Fernandez |first2=M. |year=1992 |title=Insect-eating by sympatric lowland gorillas (Gorilla g. gorilla) and chimpanzees (Pan t. troglodytes) in the Lopé Reserve, Gabon |journal=American Journal of Primatology |volume=28 |issue=1 |pages=29–40 |doi=10.1002/ajp.1350280103 |pmid=31941221 |s2cid=85569302}}{{cite journal |last1=Deblauwe |first1=I. |year=2007 |title=New insights in insect prey choice by chimpanzees and gorillas in Southeast Cameroon: The role of nutritional value |journal=American Journal of Physical Anthropology |volume=135 |issue=1 |pages=42–55 |doi=10.1002/ajpa.20703 |pmid=17902166}} Gorillas and chimpanzees may ignore or avoid each other when feeding on the same tree,{{cite book |last=Galdikas |first=B. M. |year=2005 |title=Great ape odyssey |publisher=Abrams |page=89 |isbn=978-1435110090}} but they have also been documented to form social bonds.{{cite journal|last1=Sanz|first1=C. M.|display-authors=etal|year=2022|title=Interspecific interactions between sympatric apes|journal=iScience|volume=25|issue=10|page=105059|doi=10.1016/j.isci.2022.105059|pmid=36147956 |pmc=9485909 |bibcode=2022iSci...25j5059S }} Conversely, coalitions of chimpanzees have been observed attacking families of gorillas including silverbacks and killing infants.{{Cite journal |last1=Southern |first1=L. M. |last2=Deschner |first2=T. |last3=Pika |first3=S. |year=2021 |title=Lethal coalitionary attacks of chimpanzees (Pan troglodytes troglodytes) on gorillas (Gorilla gorilla gorilla) in the wild|journal=Scientific Reports |volume=11 |issue=1 |page=14673 |doi=10.1038/s41598-021-93829-x |pmid=34282175 |pmc=8290027|bibcode=2021NatSR..1114673S }}

Behaviour

= Social structure {{anchor |Group life}} =

{{redirect2 |Blackback |Silverback ||Blackback (disambiguation) |and |Silverback (disambiguation)}}

File:Silverback.JPG

Gorillas live in groups called troops. Troops tend to be made of one adult male or silverback, with a harem of multiple adult females and their offspring.{{cite book |last=Watts |first=D. P. |year=1996 |chapter=Comparative socio-ecology of gorillas |editor1-last=McGrew |editor1-first=W. C. |editor2-last=Marchant |editor2-first=L. F. |editor3-last=Nishida |editor3-first=T. |title=Great ape societies |location=Cambridge, UK |publisher=Cambridge University Press |pages=16–28}}{{cite journal |last1=Yamagiwa |first1=J. |last2=Kahekwa |first2=J. |last3=Kanyunyi Basabose |first3=A. |year=2003 |title=Intra-specific variation in social organization of gorillas: implications for their social evolution |journal=Primates |volume=44 |pages= 359–369 |pmid=12942370 |doi=10.1007/s10329-003-0049-5 |issue=4 |s2cid=21216499}}{{sfn|Robbins|2001|pp=29–58}} However, multiple-male troops also exist. A silverback is typically more than 12 years of age, and is named for the distinctive patch of silver hair on his back, which comes with maturity. Silverbacks have large canine teeth that also come with maturity. Both males and females tend to emigrate from their natal groups. For mountain gorillas, females disperse from their natal troops more than males. Mountain gorillas and western lowland gorillas also commonly transfer to second new groups.

Mature males also tend to leave their groups and establish their own troops by attracting emigrating females. However, male mountain gorillas sometimes stay in their natal troops and become subordinate to the silverback. If the silverback dies, these males may be able to become dominant or mate with the females. This behaviour has not been observed in eastern lowland gorillas. In a single male group, when the silverback dies, the females and their offspring disperse and find a new troop.{{cite journal |last1=Stokes |first1=E. J. |last2=Parnell |first2=R. J. |last3=Olejniczak |first3=C. |year=2003 |title=Female dispersal and reproductive success in wild western lowland gorillas (Gorilla gorilla gorilla) |journal=Behavioral Ecology and Sociobiology |volume=54 |pages=329–339 |jstor=25063274 |doi=10.1007/s00265-003-0630-3 |issue=4 |bibcode=2003BEcoS..54..329S |s2cid=21995743}}{{sfn|Yamagiwa|Kahekwa|2001|pp=89–122}} Without a silverback to protect them, the infants will likely fall victim to infanticide. Joining a new group is likely to be a tactic against this.{{cite journal |last=Watts |first=D. P. |year=1989 |title=Infanticide in mountain gorillas: new cases and a reconsideration of the evidence |journal=Ethology |volume=81 |issue=1 |pages=1–18 |doi=10.1111/j.1439-0310.1989.tb00754.x|bibcode=1989Ethol..81....1W }} However, while gorilla troops usually disband after the silverback dies, female eastern lowlands gorillas and their offspring have been recorded staying together until a new silverback transfers into the group. This likely serves as protection from leopards.{{sfn|Yamagiwa|Kahekwa|2001|pp=89–122}}

File:Gorilla gorilla11.jpg

The silverback is the centre of the troop's attention, making all the decisions, mediating conflicts, determining the movements of the group, leading the others to feeding sites, and taking responsibility for the safety and well-being of the troop. Younger males subordinate to the silverback, known as blackbacks, may serve as backup protection. Blackbacks are aged between 8 and 12 years{{sfn|Robbins|2001|pp=29–58}} and lack the silver back hair. The bond that a silverback has with his females forms the core of gorilla social life. Bonds between them are maintained by grooming and staying close together.{{cite book |last=Watts |first=D. P. |year=2003 |chapter=Gorilla social relationships: a comparative review |editor1-last=Taylor |editor1-first=A. B. |editor2-last=Goldsmith |editor2-first=M. L. |title=Gorilla biology: a multidisciplinary perspective |location=Cambridge, UK |publisher=Cambridge University Press |pages=302–327}} Females form strong relationships with males to gain mating opportunities and protection from predators and infanticidal outside males.{{sfn|Watts|2001|pp=216–240}} However, aggressive behaviours between males and females do occur, but rarely lead to serious injury. Relationships between females may vary. Maternally related females in a troop tend to be friendly towards each other and associate closely. Otherwise, females have few friendly encounters and commonly act aggressively towards each other.

Females may fight for social access to males and a male may intervene. Male gorillas have weak social bonds, particularly in multiple-male groups with apparent dominance hierarchies and strong competition for mates. Males in all-male groups, though, tend to have friendly interactions and socialise through play, grooming, and staying together,{{sfn|Robbins|2001|pp=29–58}} and occasionally they even engage in homosexual interactions.{{cite journal |first=Juichi |last=Yamagiwa |title=Intra- and inter-group interactions of an all-male group of Virunga mountain gorillas (Gorilla gorilla beringei ) |journal=Primates |volume=28 |issue=1 |year=1987 |doi=10.1007/BF02382180 |pages=1–30 |s2cid=24667667}} Severe aggression is rare in stable groups, but when two mountain gorilla groups meet the two silverbacks can sometimes engage in a fight to the death, using their canines to cause deep, gaping injuries.

= Reproduction and parenting =

File:Gorillas in Uganda-3, by Fiver Löcker.jpg

Females mature at 10–12 years (earlier in captivity), and males at 11–13 years. A female's first ovulatory cycle occurs when she is six years of age, and is followed by a two-year period of adolescent infertility.{{sfn|Czekala|Robbins|2001|pp=317–339}} The estrous cycle lasts 30–33 days, with outward ovulation signs subtle compared to those of chimpanzees. The gestation period lasts 8.5 months. Female mountain gorillas first give birth at 10 years of age and have four-year interbirth intervals.{{sfn|Czekala|Robbins|2001|pp=317–339}} Males can be fertile before reaching adulthood. Gorillas mate year round.{{cite journal |last=Watts |first=D. P. |year=1991 |doi=10.1002/ajp.1350240307 |title=Mountain gorilla reproduction and sexual behavior |journal=American Journal of Primatology |volume=24 |issue=3–4 |pages=211–225 |pmid=31952383 |s2cid=85023681}}

Females will purse their lips and slowly approach a male while making eye contact. This serves to urge the male to mount her. If the male does not respond, then she will try to attract his attention by reaching towards him or slapping the ground.{{sfn|Sicotte|2001|pp=59–87}} In multiple-male groups, solicitation indicates female preference, but females can be forced to mate with multiple males.{{sfn|Sicotte|2001|pp=59–87}} Males incite copulation by approaching a female and displaying at her or touching her and giving a "train grunt". Recently, gorillas have been observed engaging in face-to-face sex, a trait once considered unique to humans and bonobos.{{cite web |url=https://www.nbcnews.com/id/wbna23148063 |title=Caught in the act! Gorillas mate face to face |first=T. C. |last=Nguyen |work=NBC News|date=13 February 2008 }}

File:Moka with baby gorilla at Pittsburgh Zoo 8, 2012-02-17.jpg

Gorilla infants are vulnerable and dependent, thus mothers, their primary caregivers, are important to their survival. Male gorillas are not active in caring for the young, but they do play a role in socialising them to other youngsters.{{sfn|Stewart|2001|pp=183–213}} The silverback has a largely supportive relationship with the infants in his troop and shields them from aggression within the group.{{sfn|Stewart|2001|pp=183–213}} Infants remain in contact with their mothers for the first five months and mothers stay near the silverback for protection.{{sfn|Stewart|2001|pp=183–213}} Infants suck at least once per hour and sleep with their mothers in the same nest.{{cite journal |last=Stewart |first=K. J. |year=1988 |title=Suckling and lactational anoestrus in wild gorillas (Gorilla gorilla) |journal=Journal of Reproduction and Fertility |pmid=3411555 |volume=83 |issue=2 |pages=627–634 |doi=10.1530/jrf.0.0830627 |doi-access=free}}

Infants begin to break contact with their mothers after five months, but only for a brief period each time. By 12 months old, infants move up to {{cvt|5|m|ft|sp=us |spell=in}} from their mothers. At around 18–21 months, the distance between mother and offspring increases and they regularly spend time away from each other.{{sfn|Fletcher|2001|pp=153–182}} In addition, nursing decreases to once every two hours. Infants spend only half of their time with their mothers by 30 months. They enter their juvenile period at their third year, and this lasts until their sixth year. At this time, gorillas are weaned and they sleep in a separate nest from their mothers.{{sfn|Stewart|2001|pp=183–213}} After their offspring are weaned, females begin to ovulate and soon become pregnant again.{{sfn|Stewart|2001|pp=183–213}} The presence of play partners, including the silverback, minimizes conflicts in weaning between mother and offspring.{{sfn|Fletcher|2001|pp=153–182}}

= Communication =

{{redirect-distinguish |Gorilla communication |Guerrilla communication}}

Twenty-five distinct vocalisations are recognised, many of which are used primarily for group communication within dense vegetation. Sounds classified as grunts and barks are heard most frequently while traveling, and indicate the whereabouts of individual group members.{{cite journal |last1=Harcourt |first1=A. H. |last2=Stewart |first2=K. J. |last3=Hauser |first3=M. |year=1993 |title=Functions of wild gorilla 'close' calls. I. Repertoire, context, and interspecific comparison |journal=Behaviour |volume=124 |issue=1–2 |page=89 |doi=10.1163/156853993X00524}} They may also be used during social interactions when discipline is required. Screams and roars signal alarm or warning, and are produced most often by silverbacks. Deep, rumbling belches suggest contentment and are heard frequently during feeding and resting periods. They are the most common form of intragroup communication.{{cite book |last=Fossey |first=D. |year=1983 |title=Gorillas in the mist |location=Boston |publisher=Houghton Mifflin Company |isbn=0395282179}}

For this reason, conflicts are most often resolved by displays and other threat behaviours that are intended to intimidate without becoming physical. As a result, fights do not occur very frequently. The ritualized charge display is unique to gorillas. The entire sequence has nine steps: (1) progressively quickening hooting, (2) symbolic feeding, (3) rising bipedally, (4) throwing vegetation, (5) chest-beating with cupped hands, (6) one leg kick, (7) sideways running, two-legged to four-legged, (8) slapping and tearing vegetation, and (9) thumping the ground with palms to end display.{{cite book |last1=Maple |first1=T. L. |last2=Hoff |first2=M.P. |year=1982 |title=Gorilla behavior |location=New York |publisher=Van Nostrand Reinhold Company}}

A gorilla's chest-beat may vary in frequency depending on its size. Smaller ones tend to have higher frequencies, while larger ones tend to be lower. They also do it the most when females are ready to mate.{{Cite journal |last=Wright |first=E. |display-authors=etal |year=2021 |title=Chest beats as an honest signal of body size in male mountain gorillas (Gorilla beringei beringei) |journal=Scientific Reports |volume=11 |issue=1 |page=6879 |doi=10.1038/s41598-021-86261-8 |pmid=33833252 |pmc=8032651 |bibcode=2021NatSR..11.6879W |doi-access=free}}

Intelligence

{{further |Primate cognition}}

{{see also |Great ape language}}

File:Gorrila tool use-Efi.jpg

Gorillas are considered highly intelligent. A few individuals in captivity, such as Koko, have been taught a subset of sign language. Like the other great apes, gorillas can laugh, grieve, have "rich emotional lives", develop strong family bonds, make and use tools, and think about the past and future.{{cite web |url=https://www.cbsnews.com/news/planet-of-no-apes-experts-warn-its-close/ |title=Planet of no apes? Experts warn it's close |archive-url=https://web.archive.org/web/20121025082433/http://www.cbsnews.com/stories/2007/09/12/tech/main3254141.shtml |archive-date=25 October 2012 |work=CBS News Online |date=2007-09-12 |url-status=live |access-date=22 March 2008}} Some researchers believe gorillas have spiritual feelings or religious sentiments. They have been shown to have cultures in different areas revolving around different methods of food preparation, and will show individual colour preferences.

=Tool use=

{{further|Tool use by animals#Gorillas}}

The following observations were made by a team led by Thomas Breuer of the Wildlife Conservation Society in September 2005. Gorillas are now known to use tools in the wild. A female gorilla in the Nouabalé-Ndoki National Park in the Republic of Congo was recorded using a stick as if to gauge the depth of water whilst crossing a swamp. A second female was seen using a tree stump as a bridge and also as a support whilst fishing in the swamp. This means all of the great apes are now known to use tools.{{Cite journal |last1=Breuer |first1=T. |last2=Ndoundou-Hockemba |first2=M. |last3=Fishlock |first3=V. |title=First observation of tool use in wild gorillas |journal=PLOS Biology |year=2005 |pages=e380 |volume=3 |issue=11 |pmid=16187795 |doi=10.1371/journal.pbio.0030380 |pmc=1236726 |doi-access=free }}

In September 2005, a two-and-a-half-year-old gorilla in the Republic of Congo was discovered using rocks to smash open palm nuts inside a game sanctuary.{{cite web |url=https://www.cbsnews.com/news/a-tough-nut-to-crack-for-evolution/ |date=2005-10-18 |title=A tough nut to crack for evolution |work=CBS News Online |access-date=18 October 2006 |url-status=live |archive-url=https://web.archive.org/web/20061114041612/http://www.cbsnews.com/stories/2005/10/18/tech/main951800.shtml |archive-date=14 November 2006}} While this was the first such observation for a gorilla, over 40 years previously, chimpanzees had been seen using tools in the wild 'fishing' for termites. Nonhuman great apes are endowed with semiprecision grips, and have been able to use both simple tools and even weapons, such as improvising a club from a convenient fallen branch.

Scientific study

American physician and missionary Thomas Staughton Savage obtained the first specimens (the skull and other bones) during his time in Liberia. The first scientific description of gorillas dates back to an article by Savage and the naturalist Jeffries Wyman in 1847 in Proceedings of the Boston Society of Natural History,{{cite book |last=Savage |first=T. S. |year=1847 |url=https://archive.org/details/proceedingsbost12histgoog/page/n243 |title=Communication describing the external character and habits of a new species of Troglodytes (T. gorilla) |archive-url=https://web.archive.org/web/20160504211124/https://books.google.com/books?id=0Hpbwjpr58AC&pg=PA245 |archive-date=4 May 2016 |publisher=Boston Society of Natural History |pages=245–247}}{{cite journal |last1=Savage |first1=T. S |last2=Wyman |first2=J. |year=1847 |url=https://books.google.com/books?id=crgrAAAAYAAJ&pg=PA417 |title=Notice of the external characters and habits of Troglodytes gorilla, a new species of orang from the Gaboon River, osteology of the same |archive-url=https://web.archive.org/web/20160520205500/https://books.google.com/books?id=crgrAAAAYAAJ&pg=PA417 |archive-date=20 May 2016 |journal=Boston Journal of Natural History |volume=5 |issue=4 |pages=417–443}} where Troglodytes gorilla is described, now known as the western gorilla. Other species of gorilla were described in the next few years.

File:French explorer Paul du Chaillu at close quarters with a gorilla.jpg at close quarters with a gorilla]]

The explorer Paul Du Chaillu was the first westerner to see a live gorilla during his travel through western equatorial Africa from 1856 to 1859. He brought dead specimens to the UK in 1861.{{Cite journal |last=McCook |first=S. |title="It may be truth, but it is not evidence": Paul du Chaillu and the legitimation of evidence in the field sciences |journal=Osiris |volume=11 |year=1996 |pages=177–197 |doi=10.1086/368759 |url=https://atrium.lib.uoguelph.ca/xmlui/bitstream/10214/7693/1/McCook%201996%20Chaillu.pdf |archive-url=https://web.archive.org/web/20170922003828/https://atrium.lib.uoguelph.ca/xmlui/bitstream/10214/7693/1/McCook%201996%20Chaillu.pdf |archive-date=2017-09-22 |url-status=live |hdl=10214/7693 |s2cid=143950182 |hdl-access=free }}{{cite web |url=http://museumsvictoria.com.au/history/gorillas.html |title=A history of Museum Victoria: Melbourne 1865: Gorillas at the museum |archive-url=https://web.archive.org/web/20080227141432/http://museumvictoria.com.au/history/gorillas.html |archive-date=27 February 2008 |publisher=Museum Victoria |access-date=27 September 2011}}{{Cite news |last1=Quammen |first1=D. |title=Book review: Planet of the ape - 'Between man and beast |first2=M. |last2=Reel |url=https://www.nytimes.com/2013/04/07/books/review/between-man-and-beast-by-monte-reel.html |date=4 April 2013 |work=The New York Times |access-date=6 April 2013 |url-status=live |archive-url=https://web.archive.org/web/20130406181545/http://www.nytimes.com/2013/04/07/books/review/between-man-and-beast-by-monte-reel.html |archive-date=6 April 2013}}

The first systematic study was not conducted until the 1920s, when Carl Akeley of the American Museum of Natural History traveled to Africa to hunt for an animal to be shot and stuffed. On his first trip, he was accompanied by his friends Mary Bradley, a mystery writer, her husband, and their young daughter Alice, who would later write science fiction under the pseudonym James Tiptree Jr. After their trip, Mary Bradley wrote On the Gorilla Trail. She later became an advocate for the conservation of gorillas, and wrote several more books (mainly for children). In the late 1920s and early 1930s, Robert Yerkes and his wife Ava helped further the study of gorillas when they sent Harold Bigham to Africa. Yerkes also wrote a book in 1929 about the great apes.

After World War II, George Schaller was one of the first researchers to go into the field and study primates. In 1959, he conducted a systematic study of the mountain gorilla in the wild and published his work. Years later, at the behest of Louis Leakey and the National Geographic, Dian Fossey conducted a much longer and more comprehensive study of the mountain gorilla. When she published her work, many misconceptions and myths about gorillas were finally disproved, including the myth that gorillas are violent.

Western lowland gorillas (G. g. gorilla) are believed to be one of the zoonotic origins of HIV/AIDS. The SIVgor Simian immunodeficiency virus that infects them is similar to a certain strain of HIV-1.{{cite journal |last1=Van Heuverswyn |first1=F. |last2=Li |first2=Y. |last3=Neel |first3=C. |display-authors=3 |last4=Bailes |first4=E. |last5=Keele |first5=B. F. |last6=Liu |first6=W. |last7=Loul |first7=S. |last8=Butel |first8=C. |last9=Liegeois |first9=F. |last10=Bienvenue |first10=Y. |last11=Ngolle |first11=E. M. |last12=Sharp |first12=P. M. |last13=Shaw |first13=G. M. |last14=Delaporte |first14=E. |last15=Hahn |first15=B. H. |last16=Peeters |first16=M. |title=Human immunodeficiency viruses: SIV infection in wild gorillas |journal=Nature |volume=444 |issue=7116 |page=164 |year=2006 |pmid=17093443 |doi=10.1038/444164a |bibcode=2006Natur.444..164V |s2cid=27475571 |doi-access=free }}{{cite journal |last1=Plantier |first1=J. |last2=Leoz |first2=M. |last3=Dickerson |first3=J. E. |display-authors=3 |last4=De Oliveira |first4=F. |last5=Cordonnier |first5=F. |last6=Lemée |first6=V. |last7=Damond |first7=F. |last8=Robertson |first8=David L |last9=Simon |first9=F. |title=A new human immunodeficiency virus derived from gorillas |journal=Nature Medicine |volume=15 |pages=871–872 |year=2009 |doi=10.1038/nm.2016 |pmid=19648927 |issue=8 |s2cid=76837833 }}{{cite journal |last1=Sharp |first1=P. M. |last2=Bailes |first2=E. |last3=Chaudhuri |first3=R. R. |last4=Rodenburg |first4=C. M. |last5=Santiago |first5=M. O. |last6=Hahn |first6=B. H. |title=The origins of acquired immune deficiency syndrome viruses: where and when? |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=356 |pages=867–876 |year=2001 |doi=10.1098/rstb.2001.0863 |pmid=11405934 |pmc=1088480 |issue=1410}}{{cite book |last1=Takebe |first1=Y. |last2=Uenishi |first2=R. |last3=Li |first3=X. |title=HIV-1: Molecular biology and pathogenesis |volume=56 |pages=1–25 |year=2008 |doi=10.1016/S1054-3589(07)56001-1 |pmid=18086407 |chapter=Global molecular epidemiology of HIV: Understanding the genesis of AIDS pandemic |series=Advances in Pharmacology |isbn=978-0123736017}}

= Genome sequencing =

The gorilla became the next-to-last great ape genus to have its genome sequenced. The first gorilla genome was generated with short read and Sanger sequencing using DNA from a female western lowland gorilla named Kamilah. This gave scientists further insight into the evolution and origin of humans. Despite the chimpanzees being the closest extant relatives of humans, 15% of the human genome was found to be more like that of the gorilla.{{Cite news |first=K. |last=Kelland |date=7 March 2012 |title=Gorilla genome sheds new light on human evolution |newspaper=Reuters |access-date=8 March 2012 |url=https://www.reuters.com/article/us-gorilla-genome-sheds-new-light-human-idUSTRE8261VA20120307 |url-status=live |archive-url=https://web.archive.org/web/20120308012545/http://www.reuters.com/article/2012/03/07/us-gorilla-genome-sheds-new-light-human-idUSTRE8261VA20120307 |archive-date=8 March 2012}} In addition, 30% of the gorilla genome "is closer to human or chimpanzee than the latter are to each other; this is rarer around coding genes, indicating pervasive selection throughout great ape evolution, and has functional consequences in gene expression."{{cite journal |first1=A. |last1=Scally |display-authors=3 |year=2012 |title=Insights into hominid evolution from the gorilla genome sequence |journal=Nature |volume=483 |pages=169–175 |doi=10.1038/nature10842 |pmid=22398555 |issue=7388 |pmc=3303130 |bibcode=2012Natur.483..169S |last2=Dutheil |first2=J. Y. |last3=Hillier |first3=L. W. |last4=Jordan |first4=G. E. |last5=Goodhead |first5=I. |last6=Herrero |first6=J. |last7=Hobolth |first7=A. |last8=Lappalainen |first8=T. |last9=Mailund |first9=T. |last10=Marques-Bonet |first10=T. |last11=McCarthy |first11=S. |last12=Montgomery |first12=S. H. |last13=Schwalie |first13=P. C. |last14=Tang |first14=Y. A. |last15=Ward |first15=M. C. |last16=Xue |first16=Y. |last17=Yngvadottir |first17=B. |last18=Alkan |first18=C. |last19=Andersen |first19=L. N. |last20=Ayub |first20=Q. |last21=Ball |first21=E. V. |last22=Beal |first22=K. |last23=Bradley |first23=B. J. |last24=Chen |first24=Y. |last25=Clee |first25=C. M. |last26=Fitzgerald |first26=S. |last27=Graves |first27=T. A. |last28=Gu |first28=Y. |last29=Heath |first29=P. |last30=Heger |first30=A. |url=https://archive-ouverte.unige.ch/unige:32177/ATTACHMENT01 |hdl=10261/80788}} Analysis of the gorilla genome has cast doubt on the idea that the rapid evolution of hearing genes gave rise to language in humans, as it also occurred in gorillas.{{Cite journal |last=Smith |first=K. |date=7 March 2012 |title=Gorilla joins the genome club |journal=Nature |url=http://www.nature.com/news/gorilla-joins-the-genome-club-1.10185 |url-status=live |archive-url=https://web.archive.org/web/20120309060208/http://www.nature.com/news/gorilla-joins-the-genome-club-1.10185 |archive-date=9 March 2012 |doi=10.1038/nature.2012.10185 |s2cid=85141639|doi-access=free }}

File:Gorillas in Ueno Zoo - 2009 Aug.webm, 2009]]

Captivity

File:Suisse zoo (25).jpg]]

Gorillas became highly prized by western zoos since the 19th century, though the earliest attempts to keep them in captive facilities ended in their early death. In the late 1920s, the care of captive gorillas significantly improved.{{sfn|Gott|Weir|2013|pp=98–107}} Colo (December 22, 1956 – January 17, 2017) of the Columbus Zoo and Aquarium was the first gorilla to be born in captivity.{{cite news |url=https://www.bbc.co.uk/news/world-us-canada-38659471 |title=Colo, the oldest gorilla in captivity, dies aged 60 |work=BBC News |access-date=18 January 2017 |date=18 January 2017}}

Captive gorillas exhibit stereotypic behaviors, including eating {{nowrap|disorders{{px2}}{{mdash}}{{px2}}}}such as regurgitation, reingestion and {{nowrap|coprophagy{{px2}}{{mdash}}{{px2}}}}self-injurious or conspecific aggression, pacing, rocking, sucking of fingers or lip smacking, and overgrooming.{{cite journal |last1=Wells |first1=D. L. |year=2005 |title=A note on the influence of visitors on the behaviour and welfare of zoo-housed gorillas |journal=Applied Animal Behaviour Science |volume=93 |issue=1–2 |pages=13–17 |doi=10.1016/j.applanim.2005.06.019}} Negative vigilance of visitor behaviors have been identified as starting, posturing and charging at visitors.{{cite journal |last1=Clark |first1=F. |last2=Fitzpatrick |first2=M. |last3=Hartley |first3=A. |last4=King |first4=A. |last5=Lee |first5=T. |last6=Routh |first6=A. |last7=Walker |first7=S |last8=George |first8=K |year=2011 |title=Relationship between behavior, adrenal activity, and environment in zoo-housed western lowland gorillas (Gorilla gorilla gorilla) |journal=Zoo Biology |volume=31 |issue=3 |pages=306–321 |doi=10.1002/zoo.20396 |pmid=21563213|url=http://researchonline.rvc.ac.uk/id/eprint/5528/ }} Groups of bachelor gorillas containing young silverbacks have significantly higher levels of aggression and wounding rates than mixed age and sex groups.{{cite journal |last1=Leeds |first1=A. |last2=Boyer |first2=D. |last3=Ross |first3=S |last4=Lukas |first4=K. |year=2015 |title=The effects of group type and young silverbacks on wounding rates in western lowland gorilla (Gorilla gorilla gorilla) groups in North American zoos |journal=Zoo Biology |volume=34 |issue=4 |pages=296–304 |doi=10.1002/zoo.21218 |pmid=26094937}}{{cite journal |last1=Stoinski |first1=T. |last2=Jaicks |first2=H. |last3=Drayton |first3=L. |year=2011 |title=Visitor effects on the behavior of captive western lowland gorillas: the importance of individual differences in examining welfare |journal=Zoo Biology |volume=31 |issue=5 |pages=586–599 |doi=10.1002/zoo.20425 |pmid=22038867}}

The use of both internal and external privacy screens on exhibit windows has been shown to alleviate stresses from visual effects of high crowd densities, leading to decreased stereotypic behaviors in the gorillas. Playing naturalistic auditory stimuli as opposed to classical music, rock music, or no auditory enrichment (which allows for crowd noise, machinery, etc. to be heard) has been noted to reduce stress behavior as well.{{cite journal |last1=Robbins |first1=L. |last2=Margulis |first2=S. |title=The effects of auditory enrichment on gorillas |journal=Zoo Biology |year=2014 |volume=33 |issue=3 |pages=197–203 |doi=10.1002/zoo.21127 |pmid=24715297}} Enrichment modifications to feed and foraging, where clover-hay is added to an exhibit floor, decrease stereotypic activities while simultaneously increasing positive food-related behaviors.

Recent research on captive gorilla welfare emphasizes a need to shift to individual assessments instead of a one-size-fits-all group approach to understanding how welfare increases or decreases based on a variety of factors. Individual characteristics such as age, sex, personality and individual histories are essential in understanding that stressors will affect each individual gorilla and their welfare differently.

Conservation status

File:Kbnpsilverbackandchild.jpg, Democratic Republic of the Congo]]

All species (and subspecies) of gorilla are listed as endangered or critically endangered on the IUCN Red List.{{cite web |title=Fin whale, mountain gorilla recovering thanks to conservation action – IUCN Red List |url=https://www.iucn.org/news/species/201811/fin-whale-mountain-gorilla-recovering-thanks-conservation-action-iucn-red-list |publisher=International Union for the Conservation of Nature |access-date=12 June 2020 |date=14 November 2018}} All gorillas are listed in Appendix I of the Convention on International Trade in Endangered Species (CITES), meaning that international export/import of the species, including in parts and derivatives, is regulated.{{Cite web|title=Appendices |url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=Convention on International Trade in Endangered Species of Wild Fauna and Flora}} Around 316,000 western lowland gorillas are thought to exist in the wild,{{cite iucn |last1=Maisels |first1=F. |last2=Bergl |first2=R. A. |last3=Williamson |first3=E. A. |title = Gorilla gorilla |amends=2016 |volume=2018 |page=e.T9404A136250858 |year=2016| doi= 10.2305/IUCN.UK.2018-2.RLTS.T9404A136250858.en}} 4,000 in zoos, thanks to conservation; eastern lowland gorillas have a population of under 5,000 in the wild and 24 in zoos. Mountain gorillas are the most severely endangered, with an estimated population of about 880 left in the wild and none in zoos.{{cite web |title=Four out of six great apes one step away from extinction – IUCN Red List |url=https://www.iucn.org/news/four-out-six-great-apes-one-step-away-extinction-%E2%80%93-iucn-red-list |access-date=15 September 2016 |date=4 September 2016 |publisher=IUCN |url-status=live |archive-url=https://web.archive.org/web/20161007061203/https://www.iucn.org/news/four-out-six-great-apes-one-step-away-extinction-%E2%80%93-iucn-red-list |archive-date=7 October 2016}} Threats to gorilla survival include habitat destruction and poaching for the bushmeat trade. Gorillas are closely related to humans, and are susceptible to diseases that humans also get infected by. In 2004, a population of several hundred gorillas in the Odzala National Park, Republic of Congo was essentially wiped out by the Ebola virus.{{cite web |title=Gorillas infecting each other with Ebola |url=https://www.newscientist.com/article/dn9517-gorillas-infecting-each-other-with-ebola.html |access-date=10 July 2006 |date=10 July 2006 |publisher=New Scientist |url-status=live |archive-url=https://web.archive.org/web/20060712213806/http://www.newscientist.com/article/dn9517-gorillas-infecting-each-other-with-ebola.html |archive-date=12 July 2006}} A 2006 study published in Science concluded more than 5,000 gorillas may have died in recent outbreaks of the Ebola virus in central Africa. The researchers indicated in conjunction with commercial hunting of these apes, the virus creates "a recipe for rapid ecological extinction".{{Cite news |title=Ebola 'kills over 5,000 gorillas' |url=http://news.bbc.co.uk/2/hi/science/nature/6220122.stm |access-date=9 December 2006 |date=8 December 2006 |publisher=BBC |url-status=live |archive-url=https://web.archive.org/web/20090329013552/http://news.bbc.co.uk/2/hi/science/nature/6220122.stm |archive-date=29 March 2009}} In captivity, it has also been observed that gorillas can also be infected with COVID-19.{{Cite web|last=Luscombe|first=Richard|date=2021-09-29|title=Thirteen gorillas test positive for Covid at Atlanta zoo |url=https://www.theguardian.com/us-news/2021/sep/11/gorillas-coronavirus-covid-atlanta-zoo|url-status=live|archive-url=https://web.archive.org/web/20210929001629/https://www.theguardian.com/us-news/2021/sep/11/gorillas-coronavirus-covid-atlanta-zoo|archive-date=2021-09-29|access-date=2021-09-30|website=The Guardian}}

Conservation efforts include the Great Apes Survival Project, a partnership between the United Nations Environment Programme and the UNESCO, and also an international treaty, the Agreement on the Conservation of Gorillas and Their Habitats, concluded under UNEP-administered Convention on Migratory Species. The Gorilla Agreement is the first legally binding instrument exclusively targeting gorilla conservation; it came into effect on 1 June 2008. Governments of countries where gorillas live placed a ban on their killing and trading, but weak law enforcement still poses a threat to them, since the governments rarely apprehend poachers, traders and consumers that rely on gorillas for profit.{{Cite web |title=Gorilla {{!}} Species |url=https://www.worldwildlife.org/species/gorilla |access-date=10 March 2021 |website=World Wildlife Fund |language=en}}

Cultural significance

{{further|Gorillas in popular culture}}

File:Death of my hunter.jpg, 1861]]

In Cameroon's Lebialem highlands, folk stories connect people and gorillas via totems; a gorilla's death means the connected person will die also. This creates a local conservation ethic.{{cite journal |last=Amir |first=Adam Pérou Hermans |title=Who Knows What About Gorillas? Indigenous Knowledge, Global Justice, and Human-Gorilla Relations |journal=IK: Other Ways of Knowing |date=15 June 2019 |volume=5 |pages=1–40 |doi=10.26209/ik560158 |s2cid=202289674 |url=https://journals.psu.edu/ik/article/view/60158/60829}} Many different indigenous peoples interact with wild gorillas. Some have detailed knowledge; the Baka have words to distinguish at least ten types of gorilla individuals, by sex, age, and relationships. In 1861, alongside tales of hunting enormous gorillas, the traveller and anthropologist Paul Du Chaillu reported the Cameroonian story that a pregnant woman who sees a gorilla will give birth to one.{{cite book |last=Du Chaillu |first=Paul |author-link=Paul Du Chaillu |year=1861 |title=Explorations and Adventures in Equatorial Africa: with Accounts of theManners and Customs of the People, and of the Chace of the Gorilla, the Crocodile, Leopard, Elephant, Hippopotamus and Other Animals |location=New York |publisher=Harper |at=Chapter 16, page 352 |url=https://archive.org/details/explorationsadve00duch_0/page/n361/mode/2up}}

In 1911, the anthropologist Albert Jenks noted the Bulu people's knowledge of gorilla behaviour and ecology, and their gorilla stories. In one such story, "The Gorilla and the Child", a gorilla speaks to people, seeking help and trust, and stealing a baby; a man accidentally kills the baby while attacking the gorilla. Even far from where gorillas live, savannah tribes pursue "cult-like worship" of the apes.{{cite book |last=Alesha |first=Matomah |year=2004 |title=Sako Ma: A Look at the Sacred Monkey Totem |location=Tucson |publisher=Matam Press |isbn=978-1411606432 |page=48}} Some beliefs are widespread among indigenous peoples. The Fang name for gorilla is ngi while the Bulu name is njamong; the root ngi means fire, denoting a positive energy. From the Central African Republic to Cameroon and Gabon, stories of reincarnations as gorillas, totems, and transformations similar to those recorded by Du Chaillu are still told in the 21st century.

Since gaining international attention, gorillas have been a recurring element of many aspects of popular culture and media.{{sfn|Gott|Weir|2013|loc=Chapters 3 and 4}} They were usually portrayed as murderous and aggressive. Inspired by Emmanuel Frémiet's Gorilla Carrying off a Woman, gorillas have been depicted kidnapping human women.{{sfn|Gott|Weir|2013|pp=122–125}} This theme was used in films such as Ingagi (1930) and most notably King Kong (1933).{{sfn|Gott|Weir|2013|pp=138–143}} The comedic play The Gorilla, which debuted in 1925, featured an escaped gorilla taking a woman from her house.{{sfn|Gott|Weir|2013|pp=126–127}} Several films would use the "escaped gorilla" trope including The Strange Case of Doctor Rx (1942), The Gorilla Man (1943), Gorilla at Large (1954) and the Disney cartoons The Gorilla Mystery (1930) and Donald Duck and the Gorilla (1944).{{sfn|Gott|Weir|2013|pp=131–135}}

Gorillas have been used as opponents to jungle-themed heroes such as Tarzan and Sheena, Queen of the Jungle,{{sfn|Gott|Weir|2013|pp=89–91, 173}} as well as superheroes. The DC Comics supervillain Gorilla Grodd is an enemy of the Flash.{{sfn|Gott|Weir|2013|p=92}} Gorillas also serve as antagonists in the 1968 film Planet of the Apes.{{sfn|Gott|Weir|2013|pp=157, 183}} More positive and sympathetic portrayals of gorillas include the films Son of Kong (1933), Mighty Joe Young (1949), Gorillas in the Mist (1988) and Instinct (1999) and the 1992 novel Ishmael.{{sfn|Gott|Weir|2013|pp=174–176}} Gorillas have been featured in video games as well, notably Donkey Kong.{{sfn|Gott|Weir|2013|p=92}}

In April 2025, a viral online debate arose regarding whether 100 men could beat a gorilla, prompting responses from celebrities and experts.{{cite news |last1=Encinas |first1=Amaris |title=Who wins in a fight between 100 men and 1 gorilla? Expert weighs in on viral debate |url=https://www.usatoday.com/story/tech/2025/04/30/experts-discuss-100-men-vs-gorilla/83367073007/ |access-date=2 May 2025 |publisher=USA TODAY |date=30 April 2025}}{{cite news |last1=Suter |first1=Tara |title=Sen. Sheehy joins viral debate over 100 men vs. a gorilla |url=https://thehill.com/blogs/in-the-know/5276406-sen-sheehy-100-men-vs-gorilla/ |access-date=2 May 2025 |publisher=The Hill |date=30 April 2025}}

See also

{{div col|colwidth=30}}

{{div col end}}

References

{{Reflist|refs=

{{MSW3 Groves |pages=181–182 |id=12100787}}

{{cite iucn |last1=Plumptre |first1=A. |last2=Robbins |first2=M. M. |last3=Williamson |first3=E. A. |title=Gorilla beringei |volume=2019 |page=e.T39994A115576640 |date=2019 |doi=10.2305/IUCN.UK.2019-1.RLTS.T39994A115576640.en}}

Kingdon, p. 93

{{cite web |first1=Tracy |last1=Lindsley |first2=Anna Bess |last2=Sorin |title=Gorilla beringei |url=https://animaldiversity.org/accounts/Gorilla_beringei/ |date=2001 |website=Animal Diversity Web |publisher=University of Michigan |access-date=August 24, 2023 |archive-date=August 30, 2023 |archive-url=https://web.archive.org/web/20230830011859/https://animaldiversity.org/accounts/Gorilla_beringei/ |url-status=live }}

{{cite iucn |last1=Maisels |first1=F. |last2=Bergl |first2=R. A. |last3=Williamson |first3=E. A. |title=Gorilla gorilla |amends=2016 |volume=2018 |page=e.T9404A136250858 |date=2018 |doi=10.2305/IUCN.UK.2018-2.RLTS.T9404A136250858.en}}

{{cite web |first1=Rebecca Ann |last1=Csomos |title=Gorilla gorilla |url=https://animaldiversity.org/accounts/Gorilla_gorilla/ |date=2008 |website=Animal Diversity Web |publisher=University of Michigan |access-date=August 24, 2023 |archive-date=October 23, 2014 |archive-url=https://web.archive.org/web/20141023025159/http://animaldiversity.ummz.umich.edu/accounts/Gorilla_gorilla/ |url-status=live }}

Kingdon, p. 91

}}

=Literature cited=

{{refbegin}}

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  • {{cite book |last1=Robbins |first1=M. M. |last2=Sicotte |first2=P. |last3=Stewart |first3=K. J. |title=Mountain gorillas: three decades of research at Karisoke |year =2001 |location=Cambridge, UK |publisher=Cambridge University Press |isbn=0521019869 |ref=none}}
  • {{cite book |last1=Czekala |first1=N. |last2=Robbins |first2=M. M. |year=2001 |title=Assessment of reproduction and stress through hormone analysis in gorillas |pages=317–339}}
  • {{cite book |last=Fletcher |first=A. |year=2001 |title=Development of infant independence from the mother in wild mountain gorillas |pages=153–182}}
  • {{cite book |last=McNeilage |first=A. |year=2001 |title=Diet and habitat use of two mountain gorilla groups in contrasting habitats in the Virungas |pages=265–292}}
  • {{cite book |last=Robbins |first=M. M. |year=2001 |title=Variation in the social system of mountain gorillas: the male perspective |pages=29–58}}
  • {{cite book |last=Sicotte |first=P. |year=2001 |title=Female mate choice in mountain gorillas |editor1-last=Robbins |pages=59–87}}
  • {{cite book |last=Stewart |first=K. J. |year=2001 |title=Social relationships of immature gorillas and silverbacks |pages=183–213}}
  • {{cite book |last=Watts |first=D. P. |year=2001 |title=Social relationships of female mountain gorillas |pages=216–240}}
  • {{cite book |last1=Yamagiwa |first1=J. |last2=Kahekwa |first2=J. |year=2001 |title=Dispersal patterns, group structure, and reproductive parameters of eastern lowland gorillas at Kahuzi in the absence of infanticide |pages=89–122}}
  • {{cite book |title=The Kingdon Field Guide to African Mammals |edition=Second |last=Kingdon |first=Jonathan |date=2015 |publisher=Bloomsbury Publishing |isbn=978-1-4729-2531-2 |ref=CITEREF_AfricanMammals}}

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