Chalmeau, Raphaël; Lardeux, Karine; Brandibas, Pierre; Gallo, Alain (1997). "Cooperative problem solving by orangutans ( Pongo pygmaeus)". International Journal of Primatology. 18 (1): 23–32. doi: 10.1023/A:1026337006136. S2CID 44204663. Oaks, Elizabeth H. (2007). Encyclopedia of World Scientists: From Around the World. Facts on File. p.260. ISBN 978-0816041305.

Estimates in the 2000s found that around 6,500 Sumatran orangutans and around 54,000 Bornean orangutans remain in the wild. [127] A 2016 study estimates a population of 14,613 Sumatran orangutans in the wild, twice that of previous population estimates, [128] while 2016 estimates suggest 104,700 Bornean orangutans exist in the wild. [116] A 2018 study found that Bornean orangutans declined by 148,500 individuals from 1999 to 2015. [129] Fewer than 800 Tapanuli orangutans are estimated to still exist, which puts the species among the most endangered of the great apes. [130] [43] Conservation centres and organisations Zoologische Gesellschaft Frankfurt Programm Director Peter Pratje works with orangutans in Bukit Tigapuluh, Indonesia. van Noordwijk, Maria A.; Sauren, Simone E.B.; Nuzuar; Abulani, Ahbam; Morrogh-Bernard, Helen C.; Atmoko, S. Suci Utami; van Schaik, Carel P. (2009). "Development of Independence". In Wich, Serge A.; Atmoko, S. Suci Utami; Setia, Tatang Mitra; van Schaik, Carel P. (eds.). Orangutans: Geographic Variation in Behavioral Ecology and Conservation. Oxford University Press. p.199. ISBN 978-0199213276. Adult females travel through the forest with their dependent offspring. Females do not live in tight social groups, but they are familiar with and have relationships with other females in the area. Adult males have large home ranges that overlap those of multiple females. Males typically range alone except when they mate with females, forming consortships that last up to several weeks. Males may also join other orangutans of various sexes and ages in feeding aggregations. Individuals within a certain range appear to know others and interact comfortably when they encounter each other.Voigt, M; Wich, S. A.; Ancrenaz, M; etal. (2018). "Global demand for natural resources eliminated more than 100,000 Bornean Orangutans". Current Biology. 28 (5): P761–769.E5. doi: 10.1016/j.cub.2018.01.053. PMID 29456144. S2CID 3756682. Ross, Marina Davila; Owren, Michael J; Zimmermann, Elke (2009). "Reconstructing the Evolution of Laughter in Great Apes and Humans". Current Biology. 19 (13): 1106–11. doi: 10.1016/j.cub.2009.05.028. PMID 19500987. S2CID 17892549. Unlike females of other non-human great ape species, orangutans do not exhibit sexual swellings to signal fertility. [64] A female first gives birth around 15 years of age and they have a six to nine year interbirth interval, the longest among the great apes. [66] Gestation is around nine months long and infants are born at a weight of 1.5–2kg (3.3–4.4lb). [18] :99 Usually only a single infant is born; twins are a rare occurrence. [67] Unlike many other primates, male orangutans do not seem to practise infanticide. This may be because they cannot ensure they will sire a female's next offspring, because she does not immediately begin ovulating again after her infant dies. [68] There is evidence that females with offspring under six years old generally avoid adult males. [69]

Wrangham, Richard W; Peterson, Dale (1996). Demonic Males: Apes and the Origins of Human Violence. Houghton Mifflin. p. 137. ISBN 978-0-395-69001-7. On January 19th, 2017, the television show BBC Breakfast aired a segment (shown below) where the hosts show off an animatronic "spy animal" from then-upcoming wildlife series Spy in the Wild, [4] a show where realistic animal robots with cameras in them spy on and interact with real animals. The clip was shared to Facebook [1] that day.Fox, E. A.; Sitompul, A. F.; van Schaik, C. P. (1999). "Intelligent tool use in wild Sumatran orangutans". In Parker, S; Mitchell, R. W.; Miles, H. L. (eds.). The Mentality of Gorillas and Orangutans. Cambridge University Press. pp.99–116. ISBN 978-0-521-03193-6. Another significant threat to orangutan survival is hunting for meat and capture of wild orangutans for sale into the pet trade. This practice is closely tied to what is called swidden agriculture: as locals burn fires to clear forested areas, orangutans within those areas flee from the conflagration and are captured for meat or sale. van Schaik, C. P.; Ancrenaz, M.; Borgen, G.; Galdikas, B.; Knott, C. D.; Singleton, I.; Suzuki, A.; Utami, S. S.; Merrill, M.; etal. (2003). "Orangutan cultures and the evolution of material culture". Science. 299 (5603): 102–05. Bibcode: 2003Sci...299..102V. doi: 10.1126/science.1078004. PMID 12511649. S2CID 25139547. All three orangutan species are considered critically endangered. Human activities have caused severe declines in populations and ranges. Threats to wild orangutan populations include poaching (for bushmeat and retaliation for consuming crops), habitat destruction and deforestation (for palm oil cultivation and logging), and the illegal pet trade. Several conservation and rehabilitation organisations are dedicated to the survival of orangutans in the wild.

Iris is an adult female hybrid orangutan. She’s charismatic and can be quite silly and playful, but also quite stubborn at times. She is the star of several cognitive research programs and enjoys participating in daily research demonstrations at Think Tank. She was born at the Zoo on April 15, 1987, and was named after the IRS (Internal Revenue Service) because of her birth date.

Habitat And Origin

a b c d Ancrenaz, M.; Gumal, M.; Marshall, A. J.; Meijaard, E.; Wich, S. A.; Husson, S. (2016). "Pongo pygmaeus". IUCN Red List of Threatened Species. 2016: e.T17975A17966347. doi: 10.2305/IUCN.UK.2016-1.RLTS.T17975A17966347.en. The word was first attested in English in 1693 by physician John Bulwer in the form Orang-Outang, [1] [7] and variants ending with -ng are found in many languages. This spelling (and pronunciation) has remained in use in English up to the present but has come to be regarded as incorrect. [8] [9] [10] The loss of "h" in utan and the shift from -ng to -n has been taken to suggest the term entered English through Portuguese. [4] In Malay, the term was first attested in 1840, not as an indigenous name but referring to how the English called the animal. [11] The word 'orangutan' in Malay and Indonesian today was borrowed from English or Dutch in the 20th century—explaining why the initial 'h' of 'hutan' is also missing. [4] a b Reese, April (2 November 2017). "Newly discovered orangutan species is also the most endangered". Nature. 551 (7679): 151. Bibcode: 2017Natur.551..151R. doi: 10.1038/nature.2017.22934. PMID 29120449.

McDowell, Robin (18 January 2009). "Palm oil frenzy threatens to wipe out orangutans". Associated Press. Archived from the original on 20 January 2009 . Retrieved 18 January 2009. van Schaik, Carel P.; Damerius, L.; Isler, K. (2013). "Wild Orangutan Males Plan and Communicate Their Travel Direction One Day in Advance". PLoS One. 8 (9): e74896. Bibcode: 2013PLoSO...874896V. doi: 10.1371/journal.pone.0074896. PMC 3770631. PMID 24040357. The presence of a fully mature dominant male may suppress secondary sexual characteristics (long hair, face pads, beards and enlarged throat sacs) in other less dominant males, and, in some cases, a wild male orangutan may never develop cheek pads. This suppression of secondary sexual characteristic does not, however, suppress his fertility, and it has been shown that unflanged male orangutans are as successful in siring offspring as fully flanged males. After reaching adolescence at four or five years, these animals become increasingly independent of their mothers. Sexual maturity for males and females in zoos is around six years, although it can take up to 10 years or more for a wild female to mature and longer than that for males. Females may stay with their mothers until they are well into their teens, allowing them to observe mothering skills as they watch their younger siblings being raised. Physical maturity, especially in males, may not be reached for several years after sexual maturity.

Rijksen, H. D. (December 1978). "A field study on Sumatran orang utans ( Pongo pygmaeus abelii, Lesson 1827): Ecology, Behaviour and Conservation". The Quarterly Review of Biology. 53 (4): 493–94. doi: 10.1086/410942. JSTOR 2826733. Unflanged males wander widely in search of oestrous females and upon finding one, will force copulation on her, the occurrence of which is unusually high among mammals. Females prefer to mate with the fitter flanged males, forming pairs with them and benefiting from their protection. [63] [55] [64] Non- ovulating females do not usually resist copulation with unflanged males, as the chance of conception is low. [64] Homosexual behaviour has been recorded in the context of both affiliative and aggressive interactions. [65] Mother orangutan with young The three orangutan species are the only extant members of the subfamily Ponginae. This subfamily also includes extinct apes such as Lufengpithecus, which occurred 8–2 mya in southern China and Thailand. [18] :50 Indopithecus, which lived in India from 9.2 to 8.6 mya; and Sivapithecus, which lived in India and Pakistan from 12.5mya until 8.5mya. [27] These animals likely lived in drier and cooler environments than orangutans do today. Khoratpithecus piriyai, which lived 5–7mya in Thailand, is believed to be the closest known relative of the living orangutans and inhabited similar environments. [18] :50 The largest known primate, Gigantopithecus, was also a member of Ponginae and lived in China, from 2mya to 300,000years ago. [28] [18] :50