Speciation and Intrasubspecific Variation of Bornean Orangutans, Pongo pygmaeus pygmaeus

Warren, K.; Verschoor, Ernst J.; Langenhuijzen, Susan; Heriyanto,; Swan, R.A.; Vigilant, Linda; Heeney, Jonathan L.

doi:10.1093/oxfordjournals.molbev.a003826

Cited by 92 publications

(136 citation statements)

References 24 publications

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“…Today, orangutans are only found on the islands of Sumatra and Borneo, in Southeast Asia. They are commonly subdivided into two species, the Sumatran Pongo abelii, and the Bornean Pongo pygmaeus (Xu & Arnason, 1996;Warren et al, 2001). The existing taxonomic subdivision of the three Bornean subspecies (P. p. pygmaeus, P. p. wurmbii and P. p. morio), described on the basis of morphological characteristics (Groves, 2001), however, does not adequately capture the genetic variation within this species (Arora et al, 2010).…”

Section: Orangutansmentioning

confidence: 99%

Orangutan tool use and the evolution of technology

Meulman

Schaik

2013

Tool Use in Animals

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Section: Orangutansmentioning

confidence: 99%

Orangutan tool use and the evolution of technology

Meulman

Schaik

2013

Tool Use in Animals

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“…Both species of orangutans (Pongo pygmaeus from Borneo and Pongo abelii from Sumatra [19,69]) are much more solitary than the other great apes and close bonds only exist between mothers and their dependent offspring. Adult animals are not often in close proximity, with the exception of consortships during which a male associates with a female while she is sexually receptive [66,74], although orangutans from Sumatra are generally more sociable than those from Borneo (see below).…”

Section: Introductionmentioning

confidence: 99%

Species-specific patterns in fecal glucocorticoid and androgen levels in zoo-living orangutans (Pongo spp.)

Weingrill¹,

Willems²,

Zimmermann³

et al. 2011

General and Comparative Endocrinology

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In contrast to most primate species, including the other great apes, orangutans maintain a fission-fusion social system in the wild without being part of a stable community. In zoos, however, they are kept in permanent groups, usually consisting of one adult male and several females. In zoo orangutans, we predict higher levels of glucocorticoids and androgens in the Bornean species compared to its congener from Sumatra, due to the much more solitary lifestyle of Bornean orangutans and the apparent higher frequency of male aggression directed towards females in this species in the wild. To compare hormone levels of the two orangutan species, we validated a fecal glucocorticoid and a fecal androgen assay. Subsequently, fecal samples from a total of 73 female and 38 male orangutans housed in 29 European zoos were analyzed to investigate the effect of species, social group size, age and (for female glucocorticoid levels) reproductive state and the presence of adult males on fecal hormone metabolite concentrations. The results of linear mixed effect models indicate that both male and female Bornean orangutans show a steeper increase in glucocorticoid levels with increasing group size than Sumatran orangutans. We therefore conclude that Sumatran zoo orangutans are better able to adjust to social housing conditions than their Bornean congeners. In addition, our analyses reveal higher glucocorticoid levels in lactating females of both species compared to non-lactating and juvenile females. Concerning androgen levels in males, our analyses revealed significantly higher concentrations in Bornean than Sumatran orangutans. These differences in both glucocorticoid and androgen output between the two species of orangutan are presumably linked to ecological and behavioral differences and could possibly be attributed to phenotypic plasticity. However, given that we found interspecific differences in hormone excretion in captivity, where both species live under very similar conditions, we conclude that this variation has a genetic basis. a b s t r a c tIn contrast to most primate species, including the other great apes, orangutans maintain a fission-fusion social system in the wild without being part of a stable community. In zoos, however, they are kept in permanent groups, usually consisting of one adult male and several females. In zoo orangutans, we predict higher levels of glucocorticoids and androgens in the Bornean species compared to its congener from Sumatra, due to the much more solitary lifestyle of Bornean orangutans and the apparent higher frequency of male aggression directed towards females in this species in the wild. To compare hormone levels of the two orangutan species, we validated a fecal glucocorticoid and a fecal androgen assay. Subsequently, fecal samples from a total of 73 female and 38 male orangutans housed in 29 European zoos were analyzed to investigate the effect of species, social group size, age and (for female glucocorticoid levels) reproductive state and the presence of adult males on f...

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“…[17][18][19][20][21] de Vos 22,23 has argued that the Indonesian paleoenvironmental record reveals a more recent divergence, while Harrison et al 15 hypothesized that orangutans dispersed into Sundaland during a cold phase in the late Pliocene (~2.7 mya) and fragmented at the start of the Pleistocene (~1.8 mya), becoming genetically distinct subsequent to this. Unfortunately little is known about the biogeography of Early Pleistocene orangutans, due in part to the limited fossil record, lack of securely dated sites, and ambiguity regarding the taxonomic identification of primate material.…”

Section: Introductionmentioning

confidence: 99%

Dental tissue proportions in fossil orangutans from mainland Asia and Indonesia

Smith

Bacon²,

Demeter

et al. 2011

Hum Origins Res

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Orangutans (Pongo) are the only great ape genus with a substantial Pleistocene and Holocene fossil record, demonstrating a much larger geographic range than extant populations. In addition to having an extensive fossil record, Pongo shows several convergent morphological similarities with Homo, including a trend of dental reduction during the past million years. While studies have documented variation in dental tissue proportions among species of Homo, little is known about variation in enamel thickness within fossil orangutans. Here we assess dental tissue proportions, including conventional enamel thickness indices, in a large sample of fossil orangutan postcanine teeth from mainland Asia and Indonesia. We find few differences between regions, except for significantly lower average enamel thickness (AET) values in Indonesian mandibular first molars. Differences between fossil and extant orangutans are more marked, with fossil Pongo showing higher AET in most postcanine teeth. These differences are significant for maxillary and mandibular first molars. Fossil orangutans show higher AET than extant Pongo due to greater enamel cap areas, which exceed increases in enamel-dentine junction length (due to geometric scaling of areas and lengths for the AET index calculation). We also find greater dentine areas in fossil orangutans, but relative enamel thickness indices do not differ between fossil and extant taxa. When changes in dental tissue proportions between fossil and extant orangutans are compared with fossil and recent Homo sapiens, Pongo appears to show isometric reduction in enamel and dentine, while crown reduction in H. sapiens appears to be due to preferential loss of dentine. Disparate selective pressures or developmental constraints may underlie these patterns. Finally, the finding of moderately thick molar enamel in fossil orangutans may represent an additional convergent dental similarity with Homo erectus, complicating attempts to distinguish these taxa in mixed Asian faunas.

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Speciation and Intrasubspecific Variation of Bornean Orangutans, Pongo pygmaeus pygmaeus

Cited by 92 publications

References 24 publications

Orangutan tool use and the evolution of technology

Orangutan tool use and the evolution of technology

Species-specific patterns in fecal glucocorticoid and androgen levels in zoo-living orangutans (Pongo spp.)

Dental tissue proportions in fossil orangutans from mainland Asia and Indonesia

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