Sumatran Orangutan Sean McCanty

Goals

• Address the background of the Sumatran Orangutan

• Research into life histories and awareness

• Describe the threats facing the orangutan in the wild

• Look at conservation and reintroduction attempts

Background

• Pongo abelli

• Bornean: Pongo pygmaeus

• Only Asiatic Great Ape genus

• Sexually dimorphic

• Males: up to 1.4 m, 80+ kg

• Female: up to 1.1m, 35+ kg

• Less than 6,600 individuals in the wild – Critically Endangered

• Restricted to forest patches in Northern Sumatra

Background

• Reddish/orange fur

• Highly arboreal – quadrumanous locomotion

• Territorial in both sexes • Flanged or unflanged males

• Less gregarious than other great apes • Ranges: 800-1500ha for females

• Mostly frutivores although important deviations

Life History

• Lifespan: Males: 58+, Females: 53+

• Age at first reproduction: 15.4

• Interbirth interval: 8.2-9.3 years

• Males disperse while females remain in natal area

• Exist in a metapopulation of at least 3 genetically distinct subpopulations

Intelligence and Culture

• Many findings of cultural learning

• Self medication using non-dietary plants and soil consumption

• A study using orphaned individuals from 2 different populations where stick use both occurred and did not occur introduced to 2 tasks testing their skills at stick use • Demonstrated a lack of genetic explanation for stick use skill level

and a “cultural” awareness

• Complex information seeking strategies • Determine whether to learn more based on cost to learn,

likelihood of error, and value of reward

Threats

• Biggest threats are from

• Habitat destruction

• Kills by humans

• Illegal pet trade

• Replacement of natural habitat with oil palm

• Additional threats from disease

• Human parasites

Reintroduction/Conservation

• Attempted PVAs to facilitate reintroduction into central Sumatra with limited success

• Difficulties due to captive individuals not knowing how to care for their young

• Most wild individuals within the bounds of national parks

• Current research into controlling conflicts between agriculture and orangutans

Summary

• Threatened by loss of habitat and exacerbated by lack of connections among suitable habitat

• Protections need better enforcement and the development of “orangutan friendly” mentality

• Better organization among conservation groups is required

Selected Bibliography

• S.A. Wich, S.S. Utami-Atmoko, T. Mitra Setia, H.D. Rijksen, C. Schürmann, J.A.R.A.M. van Hooff, C.P. van Schaik. (2004). Life history of wild Sumatran orangutans (Pongo abelii). Journal of Human Evolution. 47(6):385–398

• Alexander Nater, Natasha Arora, Maja P. Greminger, Carel P. van Schaik,Ian Singleton, Serge A. Wich, Gabriella Fredriksson, Dyah Perwitasari-Farajallah,Joko Pamungkas, and Michael Krützen (2013). Marked Population Structure and Recent Migration in the Critically Endangered Sumatran Orangutan (Pongo abelii). J. Hered 104(1): 2-13

• Thibaud Gruber, Ian Singleton, Carel van Schaik. (2012). Sumatran Orangutans Differ in Their Cultural Knowledge but Not in Their Cognitive Abilities. Current Biology. 22(23): 2231–2235

• Singleton, I., Wich, S.A. & Griffiths, M. 2008. Pongo abelii. In: IUCN 2012. IUCN

Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 25 April 2013.

• Photo credit: Prof. Tom Hilde