Home range establishment and the mechanisms of philopatry among female Bornean orangutans (Pongo pygmaeus wurmbii) at Tuanan

Ashbury, Alison M.; Willems, Erik P.; Atmoko, Sri Suci Utami; Saputra, Fajar; Schaik, Carel P. van; Noordwijk, Maria A. van

doi:10.1007/s00265-020-2818-1

Cited by 27 publications

(32 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, although orangutans are semi-solitary foragers, they live in diffuse communities of known and related individuals, in which females are resident and philopatric, and males disperse (Arora et al, 2012). Female orangutans are strongly tied to their natal areas, and the home ranges of maternal kin often overlap considerably (Van Noordwijk et al, 2012;Ashbury et al, 2020). These inherent features can pose extreme challenges for female orangutans when they are released into new forest areas (Lokuciejewski, 2018).…”

Section: Orangutan Translocation May Be Detrimental To the Populationmentioning

confidence: 99%

Importance of Small Forest Fragments in Agricultural Landscapes for Maintaining Orangutan Metapopulations

Ancrenaz

Nardiyono²,

Jopony

et al. 2021

Front. For. Glob. Change

View full text Add to dashboard Cite

Historically, orangutans (Pongo spp.) lived in large contiguous areas of intact rainforest. Today, they are also found in highly modified and fragmented landscapes dominated by oil palm or industrial timber plantations; a situation that calls for new conservation approaches. Here we report signs of orangutan presence in more than 120 small forest fragments of <500 ha in size and isolated in extensive oil palm plantations across Borneo. We confirmed the long-term presence of adult resident females with dependent young in 42% of the fragments assessed by ground survey (n = 50), and the regular sightings of males traveling across the landscape. We argue that orangutans using and living in small isolated forest patches play an essential part in the metapopulation by maintaining gene flow among larger sub-populations distributed across multiple-use landscapes. In some cases, translocations may be necessary when the animals are in imminent danger of being killed and have no other refuge. However, the impacts of removing animals from spatially dispersed metapopulations could inadvertently decrease critical metapopulation functionality necessary for long-term viability. It is clear that orangutans need natural forest to survive. However, our findings show that forest fragments within agricultural landscapes can also complement conservation areas if they are well-distributed, properly connected and managed, and if orangutan killing is prevented. Efforts to better understand the dynamics and the functionality of an orangutan metapopulation in forest-farmland landscape mosaics characteristic of the Anthropocene are urgently needed to design more efficient conservation strategies for the species across its range.

show abstract

Section: Orangutan Translocation May Be Detrimental To the Populationmentioning

confidence: 99%

Importance of Small Forest Fragments in Agricultural Landscapes for Maintaining Orangutan Metapopulations

Ancrenaz

Nardiyono²,

Jopony

et al. 2021

Front. For. Glob. Change

View full text Add to dashboard Cite

show abstract

“…After reaching sexual maturity, males spend several years in the unflanged phase, during which they roam between areas, before they transition into the flanged male phase [54]. Female orangutans, however, stay in their natal areas and settle into home ranges overlapping with their mothers' and other maternal relatives' [56][57][58].…”

Section: Introductionmentioning

confidence: 99%

“…Orangutans show vast repertoires of learned skills, in particular in the foraging context [ 57 , 58 ]. Orangutans take several years to acquire their foraging skills, and around the age of weaning, at 6.5 to 8.5 years, immatures spend as much time feeding as adults [ 60 ], and the full extent of their diet repertoires appear to have been established [ 17 , 61 ].…”

Section: Introductionmentioning

confidence: 99%

Immature wild orangutans acquire relevant ecological knowledge through sex-specific attentional biases during social learning

et al. 2021

Self Cite

View full text Add to dashboard Cite

As a part of growing up, immature orangutans must acquire vast repertoires of skills and knowledge, a process that takes several years of observational social learning and subsequent practice. Adult female and male orangutans show behavioral differences including sex-specific foraging patterns and male-biased dispersal. We investigated how these differing life trajectories affect social interest and emerging ecological knowledge in immatures. We analyzed 15 years of detailed observational data on social learning, associations, and diet repertoires of 50 immatures (16 females and 34 males), from 2 orangutan populations. Specific to the feeding context, we found sex differences in the development of social interest: Throughout the dependency period, immature females direct most of their social attention at their mothers, whereas immature males show an increasing attentional preference for individuals other than their mothers. When attending to non-mother individuals, males show a significant bias toward immigrant individuals and a trend for a bias toward adult males. In contrast, females preferentially attend to neighboring residents. Accordingly, by the end of the dependency period, immature females show a larger dietary overlap with their mothers than do immature males. These results suggest that immature orangutans show attentional biases through which they learn from individuals with the most relevant ecological knowledge. Diversifying their skills and knowledge likely helps males when they move to a new area. In sum, our findings underline the importance of fine-grained social inputs for the acquisition of ecological knowledge and skills in orangutans and likely in other apes as well.

show abstract

“…Behavioral focal data on individually recognized adult females were collected at the long-term field sites of Tuanan, Mawas Reserve, Central Kalimantan, Indonesia (02° 15′ S; 114° 44′ E) and Suaq, Gunung Leuser National Park, South Aceh, Indonesia (03° 02′ N; 97° 25′ E) between July 2003–July 2018 and June 2007–March 2018, respectively. Because parous females are in continued association with their dependent offspring (van Noordwijk et al 2009 ) and lactate over multiple years (van Noordwijk et al 2013 ), both association patterns and the cost-benefit balances incurred by sociability are likely different from nulliparous (adolescent) females (van Schaik et al 2009 ; Ashbury et al 2020 ). Therefore, only data on parous females with a dependent offspring were included in this study ( N = 20 females [Suaq: 6; Tuanan: 14]).…”

Section: Methodsmentioning

confidence: 99%

The cost of associating with males for Bornean and Sumatran female orangutans: a hidden form of sexual conflict?

Kunz

Duvot

Noordwijk

et al. 2020

Behav Ecol Sociobiol

Self Cite

View full text Add to dashboard Cite

Sexual coercion, in the form of forced copulations, is relatively frequently observed in orangutans and generally attributed to their semi-solitary lifestyle. High ecological costs of association for females may be responsible for this lifestyle and may have prevented the evolution of morphological fertility indicators (e.g., sexual swellings), which would attract (male) associates. Therefore, sexual conflict may arise not only about mating per se but also about associations, because males may benefit from associations with females to monitor their reproductive state and attempt to monopolize their sexual activities. Here, we evaluate association patterns and costs for females when associating with both males and females of two different orangutan species at two study sites: Suaq, Sumatra (Pongo abelii), and Tuanan, Borneo (Pongo pygmaeus wurmbii). Female association frequency with both males and females was higher in the Sumatran population, living in more productive habitat. Accordingly, we found that the cost of association, in terms of reduced feeding to moving ratio and increased time being active, is higher in the less sociable Bornean population. Males generally initiated and maintained such costly associations with females, and prolonged associations with males led to increased female fecal cortisol metabolite (FCM) levels at Tuanan, the Bornean population. We conclude that male-maintained associations are an expression of sexual conflict in orangutans, at least at Tuanan. For females, this cost of association may be responsible for the lack of sexual signaling, while needing to confuse paternity. Significance statement Socioecological theory predicts a trade-off between the benefits of sociality and the ecological costs of increased feeding competition. Orangutans’ semi-solitary lifestyle has been attributed to the combination of high association costs and low predation risk. Previous work revealed a positive correlation between association frequencies and habitat productivity, but did not measure the costs of association. In this comparative study, we show that females likely incur costs from involuntary, male-maintained associations, especially when they last for several days and particularly in the population characterized by lower association frequencies. Association maintenance therefore qualifies as another expression of sexual conflict in orangutans, and especially prolonged, male-maintained associations may qualify as an indirect form of sexual coercion.

show abstract

Home range establishment and the mechanisms of philopatry among female Bornean orangutans (Pongo pygmaeus wurmbii) at Tuanan

Cited by 27 publications

References 80 publications

Importance of Small Forest Fragments in Agricultural Landscapes for Maintaining Orangutan Metapopulations

Importance of Small Forest Fragments in Agricultural Landscapes for Maintaining Orangutan Metapopulations

Immature wild orangutans acquire relevant ecological knowledge through sex-specific attentional biases during social learning

The cost of associating with males for Bornean and Sumatran female orangutans: a hidden form of sexual conflict?

Contact Info

Product

Resources

About