The behavioral ecology and conservation of the orangutan (Pongo pygmaeus): A tale of two islands

  title={The behavioral ecology and conservation of the orangutan (Pongo pygmaeus): A tale of two islands},
  author={Roberto A. Delgado and Carel P. van Schaik},
  journal={Evolutionary Anthropology: Issues},
Orangutans are the only great apes found outside of Africa. At present, they occur only on the two large Sunda‐shelf islands of Sumatra and Borneo. Most researchers recognize two separate subspecies, Pongo pygmaeus abelii in Sumatra and P.p. pygmaeus in Borneo.1,2 Relative to other primates, they have a variety of unusual features. These large‐bodied frugivores are among the most solitary of anthropoid primates.3–5 They are also highly dimorphic, with the average body mass (78 kg) of males… 

Terrestriality in the bornean orangutan (Pongo pygmaeus morio) and implications for their ecology and conservation

A camera trapping study of terrestrial behavior in the northeastern Bornean orangutan, Pongo pygmaeus morio, in Wehea Forest, East Kalimantan, Indonesia, suggests that terrestriality is relatively common for the orangutans in Wehee Forest and represents a regular strategy employed by individuals of all age−sex classes.

Variation in developmental arrest among male orangutans: a comparison between a Sumatran and a Bornean population

Comparing the number of developing males and the ratios of the two male morphs at two long-term study sites shows that developmental arrest is far more common at Suaq than at Tuanan, suggesting a general contrast between the island taxa of orangutans.

Grouping Patterns and Competition Among Female Pan troglodytes schweinfurthii at Ngogo, Kibale National Park, Uganda

Ngogo females maintained relatively high levels of gregariousness, but avoided detrimental feeding competition by preferentially associating with a small subset of other community females.

Comparative phylogeography of three primate species in the Lower Kinabatangan Wildlife Sanctuary, Sabah, Malaysia

The effects of forest fragmentation and geographical barriers, especially the Kinabatangan River, on three species of primates with different social systems and dispersal abilities and the social structure of primate species profoundly influences patterns of mitochondrial genetic diversity are investigated.

Philopatry and reproductive success in Bornean orang‐utans (Pongo pygmaeus)

Examination of patterns of relatedness and parentage in a wild orang‐utan population in Borneo using noninvasively collected DNA samples from animals observed to defecate, and microsatellite markers to assess dispersal and mating strategies found that resident females were equally as related to other resident females as resident males.

Grouping behavior of Sumatran orangutans (Pongo abelii) and Tapanuli orangutans (Pongo tapanuliensis) living in forest with low fruit abundance

Orangutans in Sikundur were more likely to form parties when fruit availability was higher, but the size of daily parties was not significantly affected by fruit availability, and between‐site differences in sociality seem to reflect differences in average fruit availability.

Foraging and ranging behavior during a fallback episode: Hylobates albibarbis and Pongo pygmaeus wurmbii compared.

The approach of integrating behavioral ecology with physical measures of food may be a powerful tool for understanding the functional adaptations of primates.

Apes and Humans




Sexual Behavior of Orangutans ( Pongo pygmaeus )

Experimental laboratory data suggest that orangutans resemble other nonhuman primates in terms of the cyclic enhancement of female sexual motivation at midcycle, i.e., female orangUTans exhibit estrus, and they suggest that environmental influences have significance for captive management.

Notes on the ecology of buffy saki monkeys (Pithecia albicans, Gray 1860): A canopy seed‐predator

  • C. Peres
  • Environmental Science
    American journal of primatology
  • 1993
Whether or not feeding, sakis spent most of their time in the canopy and subcanopy, a pattern similar to that of other southwestern Amazonian saki species, but sharply different from that of Guianan sakis, which use considerably lower levels of the forest.

Dietary and dental adaptations in the Pitheciinae.

  • W. Kinzey
  • Biology
    American journal of physical anthropology
  • 1992
The dentitions of fossil pitheciins, Soriacebus and Cebupithecia, demonstrate that the hypertrophy of lower incisors plus the robustness and flaring of the canine precede development of low cusp relief on molars and premolars in the evolution of morphological features associated with sclerocarpic foraging.

Molecular genetic divergence of orang utan (Pongo pygmaeus) subspecies based on isozyme and two-dimensional gel electrophoresis.

The orang utan (Pongo pygmaeus), as currently recognized, includes two geographically separated subspecies: Pongo pygmaeus pygmaeus, which resides on Borneo, and P. p. abelii, which inhabits Sumatra.


  • D. Hooijer
  • Geology
    Evolution; international journal of organic evolution
  • 1949
A comparison of the Pleistocene and prehistoric material with that of the recent forms reveals a certain amount of differentiation which the various forms have undergone in the course of time.

Behavioral Changes in Wild Male and Female Sumatran Orangutans (Pongo pygmaeus abelii) During and Following a Resident Male Take-Over

This paper focuses on the last five years during which 48 individuals were observed in the Ketambe research site, Sumatra, Indonesia, during which a newly adult male, who has been in the area as a subadult since 1972, is challenging the resident male.

Courtship and Mating Behavior of Wild Orangutans in Sumatra

A qualitative account of the courtship and mating behavior of the orangutan in Ketambe in the Gunung Leuser Reserve in Sumatra.

The relationships of Sivapithecus and Ramapithecus and the evolution of the orang-utan

We review here the molecular data that bear on and provide a framework for interpreting hominoid relationships. Man is shown to be most closely related to chimpanzees and gorillas among extant