A captive Bornean orangutan has been seen acting as a peacemaker, breaking up fights between other warring apes.

It is the first time that an orangutan has been seen behaving in this way, say scientists who published details in the journal Primates.

Peacemakers likely intervene in squabbles to ensure they do not spiral out of control.

By Matt Walker

http://news.bbc.co.uk/earth/hi/earth_news/newsid_8466000/8466488.stm

Knott, C. D, Thompson, M. E., Stumpf, R. M. and McIntyre. M. H. 2010. Female reproductive strategies in orangutans, evidence for female choice and counterstragies to infanticide in a species with frequent sexual coercion. Proceedings of the Royal Society B-Biological Sciences. 277, 105-113.

Intersexual conflicts over mating can engender antagonistic coevolution of strategies, such as coercion by males and selective resistance by females. Orangutans are exceptional among mammals for their high levels of forced copulation. This has typically been viewed as an alternative mating tactic used by the competitively disadvantaged unflanged male morph, with little understanding of how female strategies may have shaped and responded to this behaviour. Here, we show that male morph is not by itself a good predictor of mating dynamics in wild Bornean orangutans but that female conception risk mediated the occurrence and quality of male-female interactions. Near ovulation, females mated cooperatively only with prime flanged males who they encountered at higher rates. When conception risk was low, willingness to associate and mate with non-prime males increased. Our results support the hypothesis that, together with concealed ovulation, facultative association is a mechanism of female choice in a species in which females can rarely avoid coercive mating attempts. Female resistance, which reduced copulation time, may provide an additional mechanism for mate selection. However, coercive factors were also important as prime males were frequently aggressive to females and females used mating strategies consistent with infanticide avoidance.

http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=T1Oia1GngBlgGiidD1m&page=1&doc=1&colname=WOS

Tajima, T. and Kurotori, H. 2010. Nonaggressive interventions by third parties in conflicts among captive Bornean orangutans (Pongo pygmaeus). (Journal unknown)

Whereas orangutans are regarded as semisolitary animals in the wild, several studies have reported frequent social interactions, including aggression, among orangutans in captivity. As yet, there is a lack of knowledge about how they cope with aggression. In this report, we provide a number of new observations of interventions by third parties in aggressive interactions within a captive group of Bornean orangutans (Pongo pygmaeus) in the Tama Zoological Park, Japan. We observed that an adult female and a juvenile male orangutan intervened in aggressive interactions. The victim was a newly introduced juvenile female who was unrelated to anyone in the zoo. The ways in which the orangutans intervened were not aggressive, as the interveners simply aimed to separate the opponents, and these interventions did not lead to further aggression in almost every case. Our observations suggest that third parties can play an important role in managing aggressive conflicts among captive orangutans and, under conditions in which orangutans share limited space, nonaggressive interventions by third parties for settling conflicts appear. It is possible that orangutans may actively promote the peaceful coexistence of other individuals.

http://www.ncbi.nlm.nih.gov/pubmed/20052605

Interview by HUTAN's Dr Marc Ancrenaz

The Malaysian palm oil industry has been broadly accused of
contributing to the dramatic decline in orangutan populations in Sabah,
a state in northern Borneo, over the past 30 years. The industry has
staunchly denied these charges and responded with marketing campaigns
claiming the opposite: that oil palm plantations can support and
nourish the great red apes. The issue came to a head last October at
the Orangutan Colloquium held in Kota Kinabalu. There, confronted by
orangutan biologists, the palm oil industry pledged to support
restoring forest corridors along rivers in order to help facilitate
movement of orangutans between remaining forest reserves across seas of
oil palm plantations. Attending NGOs agreed that they would need to
work with industry to find a balance that would allow the ongoing
survival of orangutans in the wild. Nevertheless, the conference was
marked by much of the same rhetoric that has characterized most of
these meetings — chief palm oil industry officials again made dubious
claims about the environmental stewardship of the industry. However,
this time, there was at least acknowledgment that palm oil needs to
play an active role in conservation.

http://news.mongabay.com/2010/0116-orangutans.html (Published by January 6, 2010)

Jaeggi, A. V. et al. 2010. Social learning of diet and foraging skills by wild Bornean orangutans: implications for culture. American Journal of Primatology. 72, 62-71.

Abstract: Studies of social learning in the wild are important to complement findings from experiments in captivity. In this field study, immature Bornean orangutans rarely foraged independently but consistently followed their mothers' choices. Their diets were essentially identical to their mothers' even though not all mothers had the same diet. This suggests vertical transmission of diet by enhancement. Also, immatures selectively observed their mothers during extractive foraging, which increased goal-directed practice but not general manipulation of similar objects, suggesting observational forms of learning of complex skills. Teaching was not observed. These results are consistent with the reported presence of food traditions and skill cultures in wild orangutans. We suggest that food traditions can develop wherever association commonly allows for social learning. However, the capacity for observational learning, and thus more complex culture, is more likely to evolve among extractive foragers with prolonged association between adults and immatures.

http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=R1i@OJJ3oa5hN68Cian&page=1&doc=3&colname=MEDLINE