Editing Orangutan (section)

== Intelligence ==

{{further|Primate cognition}}
{{see also|Great ape language}}
[[File:Orangutanspeech.webm|thumb|right|An orangutan imitating human speech<ref name="Lameira2015"/>|alt=Captive orangutan muttering from behind a cage]]

Orangutans are among the most intelligent non-human primates. Experiments suggest they can [[Object permanence#In animals|track the displacement of objects]] both visible and hidden.<ref>{{cite journal | last1 = Deaner | first1 = R. O. | last2 = van Schaik | first2 = C. P. | last3 = Johnson | first3 = V. | year = 2006 | title = Do some taxa have better domain-general cognition than others? A meta-analysis of nonhuman primate studies | url = https://www.researchgate.net/publication/232522019 | journal = Evolutionary Psychology | volume = 4 | pages = 149–96 | doi = 10.1177/147470490600400114 | s2cid = 16702785 | doi-access = free | access-date = 19 June 2020 | archive-date = 19 August 2021 | archive-url = https://web.archive.org/web/20210819071419/https://www.researchgate.net/publication/232522019_Do_Some_Taxa_Have_Better_Domain-General_Cognition_than_others_A_Meta-Analysis_of_Nonhuman_Primate_Studies | url-status = live }}</ref><ref>{{cite journal | last1 = de Blois| first1 = S. T. | last2 = Novak | first2 = M. A. | last3 = Bond | first3 = M. | year = 1998 | title = Object Permanence in Orangutans (''Pongo Pygmaeus'') and Squirrel Monkeys (''Saimiri Sciureus'') | journal = Journal of Comparative Psychology| volume = 112 |issue= 2 | pages = 137–52| doi = 10.1037/0735-7036.112.2.137 | pmid = 9642783}}</ref> [[Zoo Atlanta]] has a touch-screen computer on which their two Sumatran orangutans play games.<ref>{{cite web | author = Turner, Dorie | url = https://www.usatoday.com/tech/gaming/2007-04-12-orangutans-games_N.htm | title = Orangutans play video games (for research) at Georgia zoo | date = 12 April 2007 | newspaper = USA Today | access-date = 12 April 2007 | archive-date = 2 July 2007 | archive-url = https://web.archive.org/web/20070702082102/http://www.usatoday.com/tech/gaming/2007-04-12-orangutans-games_N.htm | url-status = live }}</ref> A 2008 study of two orangutans at the [[Leipzig Zoological Garden|Leipzig Zoo]] showed orangutans may practise "calculated [[Reciprocity (evolution)|reciprocity]]", which involves an individual aiding another with the expectation of being paid back. Orangutans are the first nonhuman species documented to do so.<ref>{{cite journal|author1=Dufour, V.|author2=Pelé, M. |author3=Neumann, M. |author4=Thierry, B. |author5=Call, J. |year=2008|title= Calculated reciprocity after all: computation behind token transfers in orang-utans |journal= [[Biology Letters]] |volume=5|issue=2|pages=172–75|doi=10.1098/rsbl.2008.0644|pmid=19126529 |pmc=2665816}}</ref>

In a 1997 study, two captive adult orangutans were tested with the [[cooperative pulling paradigm]]. Without any training, the orangutans succeeded in pulling off an object to get food in the first session. Over the course of 30 sessions, the apes succeeded more quickly, having learned to coordinate.<ref>{{cite journal|last1=Chalmeau|first1= Raphaël|first2= Karine |last2=Lardeux|first3= Pierre |last3=Brandibas|first4=Alain |last4=Gallo|title=Cooperative problem solving by orangutans (''Pongo pygmaeus'')|journal= International Journal of Primatology |volume=18|issue= 1 |year=1997|pages=23–32|doi=10.1023/A:1026337006136|s2cid= 44204663}}</ref> An adult orangutan has been documented to pass the [[mirror test]], indicating [[self-awareness]],<ref name="Suarez">{{cite journal|author1=Suárez, S. D. |author2=Gallup, G. G. |year=1981|title=Self-recognition in chimpanzees and orangutans, but not gorillas|journal=Journal of Human Evolution|volume=10|issue=2|pages=175–88|doi=10.1016/s0047-2484(81)80016-4}}</ref> while another test with a 2-year-old failed to reveal self-recognition.<ref name="Robert">{{cite journal|author=Robert, S.|title=Ontogeny of mirror behavior in two species of great apes|journal=American Journal of Primatology|volume=10|issue=2|pages=109–17|year=1986|doi=10.1002/ajp.1350100202|pmid=31979488|s2cid=85330986}}</ref>

Studies in the wild indicate that flanged male orangutans plan their movements in advance and signal them to other individuals.<ref>{{cite journal|last1=van Schaik, Carel P.|last2= Damerius, L.|last3= Isler, K.|year=2013|title=Wild Orangutan Males Plan and Communicate Their Travel Direction One Day in Advance|journal=[[PLoS One]]|volume=8|issue=9|page=e74896|doi=10.1371/journal.pone.0074896|pmid= 24040357|pmc= 3770631|bibcode= 2013PLoSO...874896V|doi-access=free}}</ref> Experiments have also suggested that orangutans can [[Displacement (linguistics)|communicate about things that are not present]]: mother orangutans remain silent in the presence of a perceived threat but when it passes, the mother produces an alarm call to their offspring to teach them about the danger.<ref>{{cite journal|last1= Lameira|first1= Adriano R.|last2=Call|first2=Josep|year=2018|title=Time-space–displaced responses in the orangutan vocal system|journal=Science Advances|volume=4|issue=11|page=eaau3401|doi=10.1126/sciadv.aau3401|pmid= 30443595|pmc= 6235548|bibcode= 2018SciA....4.3401L|doi-access=free}}</ref> Orangutans and other great apes show [[Laughter in animals|laughter]]-like vocalisations in response to physical contact such as wrestling, play chasing or tickling. This suggests that laughter derived from a common origin among primate species and therefore evolved before the origin of humans.<ref>{{cite journal |doi=10.1016/j.cub.2009.05.028 |volume=19 |issue=13 |title=Reconstructing the Evolution of Laughter in Great Apes and Humans |journal=Current Biology |pages=1106–11|year=2009 |last1=Ross |first1=Marina Davila |last2=Owren |first2=Michael J|last3=Zimmermann |first3=Elke |pmid=19500987|s2cid=17892549 |doi-access=free }}</ref> Orangutans can learn to mimic new sounds by purposely controlling the vibrations of their vocal folds, a trait that led to speech in humans.<ref name="Lameira2015">{{cite journal|last1=Lameira, A. R.|last2= Hardus, M. E.|last3= Shumaker, R. W.|last4= Wich, S. A.|last5= Menken, S. B. J.|year=2015|title=Speech-Like Rhythm in a Voiced and Voiceless Orangutan Call|journal=PLOS ONE|volume=10|issue=1|page=e116136|doi=10.1371/journal.pone.0116136|pmid= 25569211|pmc= 4287529|bibcode= 2015PLoSO..10k6136L|doi-access=free}}</ref><ref>{{cite journal|last1=Lameira, A. R.|last2= Shumaker, R. W.|year=2019|title=Orangutans show active voicing through a membranophone|journal=Scientific Reports|volume=9|issue= 1|page=12289|doi=10.1038/s41598-019-48760-7|pmid= 31444387|pmc= 6707206|bibcode= 2019NatSR...912289L|doi-access=free}}</ref> [[Bonnie (orangutan)|Bonnie]], an orangutan at the [[National Zoological Park (United States)|US National Zoo]], was recorded spontaneously whistling after hearing a caretaker. She appears to whistle without expecting a food reward.<ref name="Wich_etal2009">{{Cite journal | last1 = Wich | first1 = S. A. | last2 = Swartz | first2 = K. B. | last3 = Hardus | first3 = M. E. | last4 = Lameira | first4 = A. R. | last5 = Stromberg | first5 = E. | last6 = Shumaker | first6 = R. W. | doi = 10.1007/s10329-008-0117-y | title = A case of spontaneous acquisition of a human sound by an orangutan | journal = Primates | volume = 50 | issue = 1 | pages = 56–64 | year = 2008 | pmid = 19052691 | s2cid = 708682 }}</ref>

=== Tool use and culture ===

[[File:Orangutan using precision grip.jpg|thumb|An orangutan at the [[San Diego Zoo]] using a tool to extract orange-juice concentrate|alt=An orangutan using a stick to pick at a hole in a rock with a cup of orange-juice concentrate.]]

Tool use in orangutans was observed by primatologist [[Birutė Galdikas]] in ex-captive populations.<ref>{{cite journal | last1 = Galdikas | first1 = B. M. F. | year = 1982 | title = Orang-Utan tool use at Tanjung Putting Reserve, Central Indonesian Borneo (Kalimantan Tengah) | journal = Journal of Human Evolution | volume = 10 | pages = 19–33 |doi=10.1016/S0047-2484(82)80028-6}}</ref> Orangutans in Suaq Balimbing were recorded to develop a tool kit for use in foraging which consisted of both insect-extraction sticks for use in the hollows of trees and seed-extraction sticks for harvesting seeds from hard-husked fruit. The orangutans adjusted their tools according to the task at hand, and preference was given to oral tool use.<ref>{{cite book|last1=Fox|first1= E. A.|last2= Sitompul|first2= A. F.|last3= van Schaik|first3= C. P.|date=1999|chapter=Intelligent tool use in wild Sumatran orangutans|editor-last= Parker|editor-first= S|editor2-last= Mitchell |editor2-first=R. W. |editor3-last= Miles|editor3-first= H. L. |title=The Mentality of Gorillas and Orangutans|publisher= Cambridge University Press|pages= 99–116|isbn=978-0-521-03193-6}}</ref><ref>{{cite journal | last1 = van Schaik | first1 = C. P. | last2 = Fox | first2 = E. A. | last3 = Sitompul | first3 = A. F. | year = 1996 | title = Manufacture and use of tools in wild Sumatran orangutans – implications or human evolution | journal = [[Naturwissenschaften]] | volume = 83 | issue = 4| pages = 186–88 | doi = 10.1007/BF01143062 | pmid = 8643126 | bibcode = 1996NW.....83..186V| s2cid = 27180148 }}</ref> This preference was also found in an experimental study of captive orangutans.<ref>{{cite journal | last1 = O'Malley | first1 = R. C. | last2 = McGrew | first2 = W. C. | year = 2000 | title = Oral tool use by captive orangutans (''Pongo pygmaeus'') | journal = Folia Primatologica| volume = 71 | issue = 5| pages = 334–41 | doi = 10.1159/000021756 | pmid = 11093037| s2cid = 19354930 }}</ref> Orangutans have been observed to use sticks to poke at catfish, causing them to leap out of the water so the orangutan can grab them.<ref>{{cite journal|last1=Russon, A. E.|last2= Compost, A.|last3= Kuncoro, P.|last4= Ferisa, A.|year=2014|title=Orangutan Fish Eating, Primate Aquatic Fauna Eating, and Their Implications for the Origins of Ancestral Hominin Fish Eating|journal=Journal of Human Evolution|volume=77|pages=50–63|doi=10.1016/j.jhevol.2014.06.007|pmid=25038033}}</ref><ref>{{cite magazine |url=https://www.wired.com/wiredscience/2011/04/orangutan-tools-fishing/ |title=Orangutans use simple tools to catch fish |author=Bower, B. |magazine=[[Wired (website)|Wired]] |date=18 April 2011 |access-date=5 August 2013 |archive-date=8 July 2013 |archive-url=https://web.archive.org/web/20130708064108/http://www.wired.com/wiredscience/2011/04/orangutan-tools-fishing |url-status=live }}</ref> Orangutan have also been documented to keep tools for later.<ref>{{cite journal|author=Mulcahy, N. J.|year=2018|title=An Orangutan Hangs Up a Tool for Future Use|journal=Scientific Reports|volume=8|issue=1|pages=1–6|doi=10.1038/s41598-018-31331-7|pmid=30150738|pmc=6110832|bibcode=2018NatSR...812900M|doi-access=free}}</ref> When building a nest, orangutans appear to be able to determine which branches would better support their body weight.<ref>{{cite journal|last1=van Casteren, A.|last2= Sellers, W. I.|last3= Thorpe, S. K. S.|last4= Coward, S.|last5= Crompton, R. H.|last6= Myatt, J. P.|last7= Ennos, A. R.|year=2012|title=Nest-building orangutans demonstrate engineering know-how to produce safe, comfortable beds|journal=PNAS|volume=109|issue=18|pages=6873–77|doi=10.1073/pnas.1200902109|pmid= 22509022|pmc= 3344992|bibcode= 2012PNAS..109.6873V|doi-access=free}}</ref>

Primatologist [[Carel van Schaik|Carel P. van Schaik]] and biological anthropologist Cheryl D. Knott further investigated tool use in different wild orangutan populations. They compared geographic variations in tool use related to the processing of ''Neesia'' fruit. The orangutans of Suaq Balimbing were found to be avid users of insect and seed-extraction tools when compared to other wild orangutans.<ref name="Schaik CP 2001">{{cite journal | doi = 10.1002/ajpa.1045 | title = Geographic variation in tool use onNeesia fruits in orangutans | year = 2001 | last1 = van Schaik | first1 = Carel P. | last2 = Knott | first2 = Cheryl D. | journal = [[American Journal of Physical Anthropology]] | volume = 114 | issue = 4 | pages = 331–342 | pmid = 11275962}}</ref><ref>{{cite journal | last1 = van Schaik | first1 = CP | last2 = Van Noordwijk | first2 = MA | last3 = Wich | first3 = SA. | year = 2006 | title = Innovation in wild Bornean orangutans (''Pongo pygmaeus wurmbii'') | journal = Behaviour | volume = 143 | issue = 7| pages = 839–76 | doi = 10.1163/156853906778017944}}</ref> The scientists suggested these differences are cultural as they do not correlate with habitat. The orangutans at Suaq Balimbing are closely spaced and relatively tolerant of each other; this creates favourable conditions for the spreading of new behaviours.<ref name="Schaik CP 2001" /> Further evidence that highly social orangutans are more likely to exhibit cultural behaviours came from a study of leaf-carrying behaviours of formerly captive orangutans that were being rehabilitated on the island of Kaja in Borneo.<ref>{{cite journal | last1 = Russon | first1 = AE | last2 = Handayani | first2 = DP | last3 = Kuncoro |first3 = P | last4 = Ferisa | first4 = A. | year = 2007 | title = Orangutan leaf-carrying for nest-building: toward unraveling cultural processes | journal = [[Animal Cognition]] | volume = 10 | issue = 2| pages = 189–202 |doi = 10.1007/s10071-006-0058-z | pmid = 17160669| s2cid = 6875716 }}</ref>

Wild orangutans in Tuanan, Borneo, were reported to use tools in acoustic communication. They use leaves to amplify the kiss squeak sounds they produce. The apes may employ this method of amplification to [[Deception in animals|deceive]] the listener into believing they are larger animals.<ref name="Hardus ME 2009">{{cite journal | last1 = Hardus | first1 = M. E. | last2 = Lameira |first2 = A. R. | last3 = van Schaik | first3 = C. P. | last4 = Wich | first4 = S. A. | year = 2009 | title = Tool use in wild orang-utans modifies sound production: a functionally deceptive innovation? | journal = Proceedings of the Royal Society B | volume = 276 | issue = 1673| pages = 3689–94 | doi = 10.1098/rspb.2009.1027 | pmid=19656794 | pmc=2817314}}</ref> In 2003, researchers from six different orangutan field sites who used the same behavioural coding scheme compared the behaviours of the animals from each site. They found each orangutan population used different tools. The evidence suggested the differences were cultural: first, the extent of the differences increased with distance, suggesting cultural diffusion was occurring, and second, the size of the orangutans' cultural repertoire increased according to the amount of social contact present within the group. Social contact facilitates cultural transmission.<ref name="Schaik CP 2003">{{cite journal |last1=van Schaik |first1=C. P. |last2=Ancrenaz |first2=M. |last3=Borgen |first3=G. |last4=Galdikas |first4=B. |last5=Knott |first5=C. D. |last6=Singleton |first6=I. |last7=Suzuki |first7=A. |last8=Utami |first8=S. S. |last9=Merrill |first9=M.|year=2003 |title=Orangutan cultures and the evolution of material culture |journal=Science |volume=299 |issue=5603 |pages=102–05 |doi=10.1126/science.1078004 |pmid=12511649|display-authors=etal|bibcode=2003Sci...299..102V |s2cid=25139547 }}</ref>

During a [[Field research|field observation]] in 2022, a male Sumatran orangutan, known to researchers as Rakus, chewed ''[[Fibraurea tinctoria]]'' vine leaves and [[Zoopharmacognosy|applied]] the mashed plant material to an open wound on his face.<ref name=wound>{{Cite journal|display-authors=3 |last1=Laumer |first1=Isabelle B. |last2=Rahman |first2=Arif |last3=Rahmaeti |first3=Tri |last4=Azhari |first4=Ulil |last5=Hermansyah |last6=Atmoko |first6=Sri Suci Utami |last7=Schuppli |first7=Caroline |date=2 May 2024 |title=Active self-treatment of a facial wound with a biologically active plant by a male Sumatran orangutan |journal=Scientific Reports |language=en |volume=14 |issue=1 |page=8932 |doi=10.1038/s41598-024-58988-7 |pmid=38698007 |pmc=11066025 |issn=2045-2322}}</ref> According to [[Primatology|primatologists]] who had been observing Rakus at a nature preserve, "Five days later the facial wound was closed, while within a few weeks it had healed, leaving only a small scar".<ref name=wound/><ref>{{Cite news |last=Davis |first=Nicola |last2= |first2= |date=2 May 2024 |title=Orangutan seen treating wound with medicinal herb in first for wild animals |url=https://www.theguardian.com/science/article/2024/may/02/orangutan-seen-treating-wound-with-medicinal-herb-in-first-for-wild-animals-max-planck-institute-sumatra |access-date=2 May 2024 |work=The Guardian |language=en-GB |issn=0261-3077 |archive-date=2 May 2024 |archive-url=https://web.archive.org/web/20240502152144/https://www.theguardian.com/science/article/2024/may/02/orangutan-seen-treating-wound-with-medicinal-herb-in-first-for-wild-animals-max-planck-institute-sumatra |url-status=live }}</ref>

=== Personhood ===

{{Main|Great ape personhood|Great Ape Project|Great ape research ban}}

In June 2008, Spain would become the first country to recognise the rights of some non-human great apes, based on the guidelines of the [[Great Ape Project]], which are that chimpanzees, [[bonobo]]s, orangutans, and gorillas are not to be used for animal experiments.<ref>{{cite news |author=Glendinning, L. |url=https://www.theguardian.com/world/2008/jun/26/humanrights.animalwelfare?gusrc=rss&feed=networkfront |title=Spanish parliament approves 'human rights' for apes |newspaper=The Guardian |date=26 June 2008 |access-date=10 November 2008 |archive-date=26 August 2009 |archive-url=https://web.archive.org/web/20090826115218/http://www.guardian.co.uk/world/2008/jun/26/humanrights.animalwelfare?gusrc=rss&feed=networkfront |url-status=live }}</ref><ref>{{cite news |author=Singer, P. |url=https://www.theguardian.com/commentisfree/2008/jul/18/animalwelfare.animalbehaviour |title=Of great apes and men |newspaper=The Guardian |date=18 July 2008 |access-date=10 November 2008 |archive-date=13 November 2012 |archive-url=https://web.archive.org/web/20121113090321/http://www.guardian.co.uk/commentisfree/2008/jul/18/animalwelfare.animalbehaviour |url-status=live }}</ref> In December 2014, a court in Argentina ruled that an orangutan named Sandra at the [[Buenos Aires Zoo]] must be moved to a sanctuary in Brazil to provide her "partial or controlled freedom". Sandra has since been relocated to [[Center for Great Apes|The Center for Great Apes]] in the [[United States]], as it is the only accredited orangutan [[sanctuary]] in the [[Americas]].<ref>{{cite web | url=https://centerforgreatapes.org/orangutan/sandra/ | title=Sandra }}</ref> Animal rights groups like Great Ape Project Argentina argued the ruling should apply to all species in captivity, and legal specialists from the Argentina's Federal Chamber of [[Court of cassation|Criminal Cassatio]] considered the ruling applicable only to non-human hominids.<ref>{{cite web |url=https://edition.cnn.com/2014/12/23/world/americas/feat-orangutan-rights-ruling/ |title=Argentine orangutan granted unprecedented legal rights |author=Giménez, Emiliano |publisher=CNN |date=23 December 2014 |access-date=15 June 2020 |archive-date=3 April 2021 |archive-url=https://web.archive.org/web/20210403030759/https://edition.cnn.com/2014/12/23/world/americas/feat-orangutan-rights-ruling/ |url-status=live }}</ref>