1
|
Scott AM, Banes GL, Setiadi W, Saragih JR, Susanto TW, Mitra Setia T, Knott CD. Flanged males have higher reproductive success in a completely wild orangutan population. PLoS One 2024; 19:e0296688. [PMID: 38335166 PMCID: PMC10857694 DOI: 10.1371/journal.pone.0296688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/17/2023] [Indexed: 02/12/2024] Open
Abstract
Male orangutans (Pongo spp.) exhibit bimaturism, an alternative reproductive tactic, with flanged and unflanged males displaying two distinct morphological and behavioral phenotypes. Flanged males are larger than unflanged males and display secondary sexual characteristics which unflanged males lack. The evolutionary explanation for alternative reproductive tactics in orangutans remains unclear because orangutan paternity studies to date have been from sites with ex-captive orangutans, provisioning via feeding stations and veterinary care, or that lack data on the identity of mothers. Here we demonstrate, using the first long-term paternity data from a site free of these limitations, that alternative reproductive tactics in orangutans are condition-dependent, not frequency-dependent. We found higher reproductive success by flanged males than by unflanged males, a pattern consistent with other Bornean orangutan (Pongo pygmaeus) paternity studies. Previous paternity studies disagree on the degree of male reproductive skew, but we found low reproductive skew among flanged males. We compare our findings and previous paternity studies from both Bornean and Sumatran orangutans (Pongo abelii) to understand why these differences exist, examining the possible roles of species differences, ecology, and human intervention. Additionally, we use long-term behavioral data to demonstrate that while flanged males can displace unflanged males in association with females, flanged males are unable to keep other males from associating with a female, and thus they are unable to completely mate guard females. Our results demonstrate that alternative reproductive tactics in Bornean orangutans are condition-dependent, supporting the understanding that the flanged male morph is indicative of good condition. Despite intense male-male competition and direct sexual coercion by males, female mate choice is effective in determining reproductive outcomes in this population of wild orangutans.
Collapse
Affiliation(s)
- Amy M. Scott
- Department of Anthropology, Boston University, Boston, Massachusetts, United States of America
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Graham L. Banes
- Wisconsin National Primate Research Center, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- The Orang-Utan Conservation Genetics Project, Madison, Wisconsin, United States of America
| | - Wuryantari Setiadi
- Eijkman Research Center for Molecular Biology, National Agency for Research and Innovation (BRIN), The Science and Technology Center of Soekarno, Cibinong, West Java, Indonesia
| | - Jessica R. Saragih
- Eijkman Research Center for Molecular Biology, National Agency for Research and Innovation (BRIN), The Science and Technology Center of Soekarno, Cibinong, West Java, Indonesia
| | - Tri Wahyu Susanto
- Departemen of Biology, Faculty of Biology and Agricultural, Universitas Nasional, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta, Indonesia
| | - Tatang Mitra Setia
- Departemen of Biology, Faculty of Biology and Agricultural, Universitas Nasional, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta, Indonesia
| | - Cheryl D. Knott
- Department of Anthropology, Boston University, Boston, Massachusetts, United States of America
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| |
Collapse
|
2
|
van Noordwijk MA, LaBarge LR, Kunz JA, Marzec AM, Spillmann B, Ackermann C, Rianti P, Vogel ER, Atmoko SSU, Kruetzen M, van Schaik CP. Reproductive success of Bornean orangutan males: scattered in time but clustered in space. Behav Ecol Sociobiol 2023; 77:134. [PMID: 38076722 PMCID: PMC10700224 DOI: 10.1007/s00265-023-03407-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 12/22/2023]
Abstract
Abstract The social and mating systems of orangutans, one of our closest relatives, remain poorly understood. Orangutans (Pongo spp.) are highly sexually dimorphic and females are philopatric and maintain individual, but overlapping home ranges, whereas males disperse, are non-territorial and wide-ranging, and show bimaturism, with many years between reaching sexual maturity and attaining full secondary sexual characteristics (including cheek pads (flanges) and emitting long calls). We report on 21 assigned paternities, among 35 flanged and 15 unflanged, genotyped male Bornean orangutans (Pongo pygmaeus wurmbii), studied from 2003 to 2018 in Tuanan (Central Kalimantan, Indonesia). All 10 infants born since mid-2003 with an already identified sire were sired by flanged males. All adult males ranged well beyond the study area (c. 1000 ha), and their dominance relations fluctuated even within short periods. However, 5 of the 10 identified sires had multiple offspring within the monitored area. Several sired over a period of c. 10 years, which overlapped with siring periods of other males. The long-calling behavior of sires indicated they were not consistently dominant over other males in the area around the time of known conceptions. Instead, when they were seen in the area, the known sires spent most of their time within the home ranges of the females whose offspring they sired. Overall, successful sires were older and more often resident than others. Significance statement It is difficult to assess reproductive success for individuals of long-lived species, especially for dispersing males, who cannot be monitored throughout their lives. Due to extremely long interbirth intervals, orangutans have highly male-skewed operational sex ratios and thus intensive male-male competition for every conception. Paternity analyses matched 21 immature Bornean orangutans with their most likely sire (only 10 of 50 genotyped males) in a natural population. Half of these identified sires had multiple offspring in the study area spread over periods of at least 10 years, despite frequently ranging outside this area. Dominance was a poor predictor of success, but, consistent with female mating tactics to reduce the risk of infanticide, known "sires" tended to have relatively high local presence, which seems to contribute to the males' siring success. The results highlight the importance of large protected areas to enable a natural pattern of dispersal and ranging. Supplementary Information The online version contains supplementary material available at 10.1007/s00265-023-03407-6.
Collapse
Affiliation(s)
- Maria A. van Noordwijk
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Comparative Socio-Ecology Group, May Planck Institute of Animal Behavior, Konstanz, Germany
| | - Laura R. LaBarge
- Comparative Socio-Ecology Group, May Planck Institute of Animal Behavior, Konstanz, Germany
| | - Julia A. Kunz
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Institute des Sciences de l’Evolution Montpellier, University of Montpellier, Montpellier, France
| | - Anna M. Marzec
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
| | - Brigitte Spillmann
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
| | - Corinne Ackermann
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
| | - Puji Rianti
- Division of Animal Biosystematics and Ecology, Department of Biology, IPB University, Bogor, Indonesia
- Primate Research Center, IPB University, Bogor, Indonesia
| | - Erin R. Vogel
- Department of Anthropology, Center for Human Evolution Studies, Rutgers, The State University of New Jersey, New Brunswick, USA
| | | | - Michael Kruetzen
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
| | - Carel P. van Schaik
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Comparative Socio-Ecology Group, May Planck Institute of Animal Behavior, Konstanz, Germany
- Center for the Interdisciplinary Study of Language Evolution (ISLE), University of Zurich, Zürich, Switzerland
| |
Collapse
|
3
|
Bridgeland-Stephens L, Thorpe SKS, Chappell J. Potential resilience treatments for orangutans ( Pongo spp.): Lessons from a scoping review of interventions in humans and other animals. Anim Welf 2023; 32:e77. [PMID: 38487448 PMCID: PMC10937215 DOI: 10.1017/awf.2023.97] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 09/25/2023] [Accepted: 11/02/2023] [Indexed: 03/17/2024]
Abstract
Wild orangutans (Pongo spp.) rescued from human-wildlife conflict must be adequately rehabilitated before being returned to the wild. It is essential that released orangutans are able to cope with stressful challenges such as food scarcity, navigating unfamiliar environments, and regaining independence from human support. Although practical skills are taught to orangutans in rehabilitation centres, post-release survival rates are low. Psychological resilience, or the ability to 'bounce back' from stress, may be a key missing piece of the puzzle. However, there is very little knowledge about species-appropriate interventions which could help captive orangutans increase resilience to stress. This scoping review summarises and critically analyses existing human and non-human animal resilience literature and provides suggestions for the development of interventions for orangutans in rehabilitation. Three scientific databases were searched in 2021 and 2023, resulting in 63 human studies and 266 non-human animal studies. The first section brings together human resilience interventions, identifying common themes and assessing the applicability of human interventions to orangutans in rehabilitation. The second section groups animal interventions into categories of direct stress, separation stress, environmental conditions, social stress, and exercise. In each category, interventions are critically analysed to evaluate their potential for orangutans in rehabilitation. The results show that mild and manageable forms of intervention have the greatest potential benefit with the least amount of risk. The study concludes by emphasising the need for further investigation and experimentation, to develop appropriate interventions and measure their effect on the post-release survival rate of orangutans.
Collapse
Affiliation(s)
| | | | - Jackie Chappell
- School of Biosciences, University of Birmingham, Birmingham, UK
| |
Collapse
|
4
|
Kunz JA, Duvot GJ, Ashbury AM, Willems EP, Spillmann B, Dunkel LP, Bin Abdullah M, Schuppli C, Vogel ER, Utami Atmoko SS, van Noordwijk MA, van Schaik CP. Alternative reproductive tactics of unflanged and flanged male orangutans revisited. Am J Primatol 2023; 85:e23535. [PMID: 37475573 DOI: 10.1002/ajp.23535] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 07/06/2023] [Accepted: 07/08/2023] [Indexed: 07/22/2023]
Abstract
In many slowly developing mammal species, males reach sexual maturity well before they develop secondary sexual characteristics. Sexually mature male orangutans have exceptionally long periods of developmental arrest. The two male morphs have been associated with behavioral alternative reproductive tactics, but this interpretation is based on cross-sectional analyses predominantly of Northwest Sumatran populations. Here we present the first longitudinal analyses of behavioral changes of 10 adult males that have been observed in both unflanged and flanged morph. We also analyzed long-term behavioral data on an additional 143 individually identified males from two study sites, Suaq (Sumatra, Pongo abelii) and Tuanan (Borneo, Pongo pygmaeus wurmbii), to assess male mating tactics cross-sectionally in relation to population, male morph (unflanged and flanged), and other socio-ecological factors. Both our longitudinal and cross-sectional results confirm and refine previous cross-sectional accounts of the differences in mating tactics between the unflanged and the flanged male morphs. In the unflanged morph, males exhibit higher sociability, particularly with females, and higher rates of both copulation and sexual coercion than in the flanged morph. Based on our results and those of previous studies showing that females prefer flanged males, and that flanged males have higher reproductive success, we conclude that unflanged males face a trade-off between avoiding male-male contest competition and gaining mating access to females, and thus follow a "best-of-a-bad-job" mating strategy.
Collapse
Affiliation(s)
- Julia A Kunz
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Institute des Sciences de l'Evolution Montpellier, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Guilhem J Duvot
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
| | - Alison M Ashbury
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Department of Biology, University of Konstanz, Konstanz, Germany
- Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany
| | - Erik P Willems
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
| | - Brigitte Spillmann
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Lynda P Dunkel
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
| | - Misdi Bin Abdullah
- Department of Biology, Faculty of Biology and Primates Research Center, Universitas Nasional, South Jakarta, Indonesia
| | - Caroline Schuppli
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany
| | - Erin R Vogel
- Department of Anthropology, Rutgers The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Sri Suci Utami Atmoko
- Department of Biology, Faculty of Biology and Primates Research Center, Universitas Nasional, South Jakarta, Indonesia
| | - Maria A van Noordwijk
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Comparative Socioecology Group, Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany
| | - Carel P van Schaik
- Department of Evolutionary Anthropology, University of Zurich, Zürich, Switzerland
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- Comparative Socioecology Group, Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany
| |
Collapse
|
5
|
Laméris DW, van Berlo E, Roth TS, Kret ME. No Evidence for Biased Attention Towards Emotional Scenes in Bornean Orangutans ( Pongo pygmaeus). AFFECTIVE SCIENCE 2022; 3:772-782. [PMID: 36519144 PMCID: PMC9743850 DOI: 10.1007/s42761-022-00158-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 09/23/2022] [Indexed: 06/17/2023]
Abstract
UNLABELLED Attention may be swiftly and automatically tuned to emotional expressions in social primates, as has been demonstrated in humans, bonobos, and macaques, and with mixed evidence in chimpanzees, where rapid detection of emotional expressions is thought to aid in navigating their social environment. Compared to the other great apes, orangutans are considered semi-solitary, but still form temporary social parties in which sensitivity to others' emotional expressions may be beneficial. The current study investigated whether implicit emotion-biased attention is also present in orangutans (Pongo pygmaeus). We trained six orangutans on the dot-probe paradigm: an established paradigm used in comparative studies which measures reaction time in response to a probe replacing emotional and neutral stimuli. Emotional stimuli consisted of scenes depicting conspecifics having sex, playing, grooming, yawning, or displaying aggression. These scenes were contrasted with neutral scenes showing conspecifics with a neutral face and body posture. Using Bayesian mixed modeling, we found no evidence for an overall emotion bias in this species. When looking at emotion categories separately, we also did not find substantial biases. We discuss the absence of an implicit attention bias for emotional expressions in orangutans in relation to the existing primate literature, and the methodological limitations of the task. Furthermore, we reconsider the emotional stimuli used in this study and their biological relevance. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s42761-022-00158-x.
Collapse
Affiliation(s)
- D. W. Laméris
- Behavioural Ecology and Ecophysiology Group, Department of Biology, University of Antwerp, Wilrijk, Antwerp, Belgium
- Antwerp ZOO Centre for Research & Conservation (CRC), Royal Zoological Society of Antwerp (RZSA), Antwerp, Belgium
| | - E. van Berlo
- Cognitive Psychology Unit, Institute of Psychology, Leiden University, Leiden, The Netherlands
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Amsterdam, The Netherlands
| | - T. S. Roth
- Cognitive Psychology Unit, Institute of Psychology, Leiden University, Leiden, The Netherlands
- Apenheul Primate Park, Apeldoorn, The Netherlands
| | - M. E. Kret
- Cognitive Psychology Unit, Institute of Psychology, Leiden University, Leiden, The Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden, The Netherlands
| |
Collapse
|
6
|
Graham KE, Badihi G, Safryghin A, Grund C, Hobaiter C. A socio-ecological perspective on the gestural communication of great ape species, individuals, and social units. ETHOL ECOL EVOL 2022; 34:235-259. [PMID: 35529671 PMCID: PMC9067943 DOI: 10.1080/03949370.2021.1988722] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Over the last 30 years, most research on non-human primate gestural communication has been produced by psychologists, which has shaped the questions asked and the methods used. These researchers have drawn on concepts from philosophy, linguistics, anthropology, and ethology, but despite these broad influences the field has neglected to situate gestures into the socio-ecological context in which the diverse species, individuals, and social-units exist. In this review, we present current knowledge about great ape gestural communication in terms of repertoires, meanings, and development. We fold this into a conversation about variation in other types of ape social behaviour to identify areas for future research on variation in gestural communication. Given the large variation in socio-ecological factors across species and social-units (and the individuals within these groups), we may expect to find different preferences for specific gesture types; different needs for communicating specific meanings; and different rates of encountering specific contexts. New tools, such as machine-learning based automated movement tracking, may allow us to uncover potential variation in the speed and form of gesture actions or parts of gesture actions. New multi-group multi-generational datasets provide the opportunity to apply analyses, such as Bayesian modelling, which allows us to examine these rich behavioural landscapes. Together, by expanding our questions and our methods, researchers may finally be able to study great ape gestures from the perspective of the apes themselves and explore what this gestural communication system reveals about apes’ thinking and experience of their world.
Collapse
Affiliation(s)
- Kirsty E. Graham
- School of Psychology & Neuroscience, University of St Andrews, St Mary’s Quad, South St, St Andrews KY16 9JP, Scotland, UK
| | - Gal Badihi
- School of Psychology & Neuroscience, University of St Andrews, St Mary’s Quad, South St, St Andrews KY16 9JP, Scotland, UK
| | - Alexandra Safryghin
- School of Psychology & Neuroscience, University of St Andrews, St Mary’s Quad, South St, St Andrews KY16 9JP, Scotland, UK
| | - Charlotte Grund
- School of Psychology & Neuroscience, University of St Andrews, St Mary’s Quad, South St, St Andrews KY16 9JP, Scotland, UK
| | - Catherine Hobaiter
- School of Psychology & Neuroscience, University of St Andrews, St Mary’s Quad, South St, St Andrews KY16 9JP, Scotland, UK
| |
Collapse
|
7
|
After the smoke has cleared: Extended low fruit productivity following forest fires decreased gregariousness and social tolerance among wild female Bornean orangutans (Pongo pygmaeus wurmbii). INT J PRIMATOL 2021. [DOI: 10.1007/s10764-021-00263-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AbstractAs climate change continues to fundamentally alter resource landscapes, the ability to flexibly respond to spatio-temporal changes in the distribution of preferred food sources is increasingly important for the overall health and fitness of animals living in seasonal, variable, and/or changing environments. Here, we investigate the effects of an uncharacteristically long period of fruit scarcity, following widespread thick haze caused by peat and forest fires in 2015, on the behaviour and sociality of female Bornean orangutans (Pongo pygmaeus wurmbii). We collected data from 2010 to 2018 at Tuanan, Central Kalimantan, Indonesia, and compared the activity, diet, and association patterns of adult females during low-fruit periods before the fires, i.e., regular, seasonal periods of low fruit availability (“pre-fire”), and after the fires, i.e., during the extended period of low fruit availability (“post-fire”). First, we found that, post-fire, female orangutans adopted a more extreme energy-saving activity pattern and diet — resting more, travelling less, and diet-switching to less-preferred foods — compared to pre-fire. Second, we found that the probabilities of association between females and their weaned immature offspring, and between related and unrelated adult females were lower, and the probability of agonism between unrelated females was higher, post-fire than pre-fire. This change in energetic strategy, and the general reduction in gregariousness and social tolerance, demonstrates how forest fires can have lasting consequences for orangutans. Fission–fusion species such as orangutans can mitigate the effects of changes in resource landscapes by altering their (sub)grouping patterns; however, this may have long-term indirect consequences on their fitness.
Collapse
|
8
|
Kuswanda W, Alikodra HS, Margules C, Supriatna J. The estimation of demographic parameters and a growth model for Tapanuli orangutan in the Batang Toru Landscape, South Tapanuli Regency, Indonesia. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
9
|
Fröhlich M, Bartolotta N, Fryns C, Wagner C, Momon L, Jaffrezic M, Mitra Setia T, van Noordwijk MA, van Schaik CP. Multicomponent and multisensory communicative acts in orang-utans may serve different functions. Commun Biol 2021; 4:917. [PMID: 34316012 PMCID: PMC8316500 DOI: 10.1038/s42003-021-02429-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 07/07/2021] [Indexed: 02/07/2023] Open
Abstract
From early infancy, human face-to-face communication is multimodal, comprising a plethora of interlinked communicative and sensory modalities. Although there is also growing evidence for this in nonhuman primates, previous research rarely disentangled production from perception of signals. Consequently, the functions of integrating articulators (i.e. production organs involved in multicomponent acts) and sensory channels (i.e. modalities involved in multisensory acts) remain poorly understood. Here, we studied close-range social interactions within and beyond mother-infant pairs of Bornean and Sumatran orang-utans living in wild and captive settings, to examine use of and responses to multicomponent and multisensory communication. From the perspective of production, results showed that multicomponent acts were used more than the respective unicomponent acts when the presumed goal did not match the dominant outcome for a specific communicative act, and were more common among non-mother-infant dyads and Sumatran orang-utans. From the perception perspective, we found that multisensory acts were more effective than the respective unisensory acts, and were used more in wild compared to captive populations. We argue that multisensory acts primarily facilitate effectiveness, whereas multicomponent acts become relevant when interaction outcomes are less predictable. These different functions underscore the importance of distinguishing between production and perception in studies of communication.
Collapse
Affiliation(s)
- Marlen Fröhlich
- Department of Anthropology, University of Zurich, Zurich, Switzerland.
| | | | - Caroline Fryns
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Colin Wagner
- DEPE-IPHC - Département Ecologie, Physiologie et Ethologie, University of Strasbourg, Strasbourg, France
| | - Laurene Momon
- DEPE-IPHC - Département Ecologie, Physiologie et Ethologie, University of Strasbourg, Strasbourg, France
| | - Marvin Jaffrezic
- DEPE-IPHC - Département Ecologie, Physiologie et Ethologie, University of Strasbourg, Strasbourg, France
| | | | | | - Carel P van Schaik
- Department of Anthropology, University of Zurich, Zurich, Switzerland
- Center for the Interdisciplinary Study of Language Evolution (ISLE), University of Zurich, Zurich, Switzerland
| |
Collapse
|
10
|
Influences of Forest Structure on the Density and Habitat Preference of Two Sympatric Gibbons (Symphalangus syndactylus and Hylobates lar). INT J PRIMATOL 2021. [DOI: 10.1007/s10764-021-00199-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
11
|
Machine Learning Data Imputation and Prediction of Foraging Group Size in a Kleptoparasitic Spider. MATHEMATICS 2021. [DOI: 10.3390/math9040415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cost–benefit analysis is widely used to elucidate the association between foraging group size and resource size. Despite advances in the development of theoretical frameworks, however, the empirical systems used for testing are hindered by the vagaries of field surveys and incomplete data. This study developed the three approaches to data imputation based on machine learning (ML) algorithms with the aim of rescuing valuable field data. Using 163 host spider webs (132 complete data and 31 incomplete data), our results indicated that the data imputation based on random forest algorithm outperformed classification and regression trees, the k-nearest neighbor, and other conventional approaches (Wilcoxon signed-rank test and correlation difference have p-value from < 0.001–0.030). We then used rescued data based on a natural system involving kleptoparasitic spiders from Taiwan and Vietnam (Argyrodes miniaceus, Theridiidae) to test the occurrence and group size of kleptoparasites in natural populations. Our partial least-squares path modelling (PLS-PM) results demonstrated that the size of the host web (T = 6.890, p = 0.000) is a significant feature affecting group size. The resource size (T = 2.590, p = 0.010) and the microclimate (T = 3.230, p = 0.001) are significant features affecting the presence of kleptoparasites. The test of conformation of group size distribution to the ideal free distribution (IFD) model revealed that predictions pertaining to per-capita resource size were underestimated (bootstrap resampling mean slopes <IFD predicted slopes, p < 0.001). These findings highlight the importance of applying appropriate ML methods to the handling of missing field data.
Collapse
|
12
|
The cost of associating with males for Bornean and Sumatran female orangutans: a hidden form of sexual conflict? Behav Ecol Sociobiol 2020; 75:6. [PMID: 33408436 PMCID: PMC7773621 DOI: 10.1007/s00265-020-02948-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/02/2020] [Accepted: 12/09/2020] [Indexed: 12/29/2022]
Abstract
Abstract 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. Supplementary Information The online version contains supplementary material available at 10.1007/s00265-020-02948-4.
Collapse
|
13
|
van Berlo E, Díaz-Loyo AP, Juárez-Mora OE, Kret ME, Massen JJM. Experimental evidence for yawn contagion in orangutans (Pongo pygmaeus). Sci Rep 2020; 10:22251. [PMID: 33335177 PMCID: PMC7747555 DOI: 10.1038/s41598-020-79160-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 12/03/2020] [Indexed: 11/17/2022] Open
Abstract
Yawning is highly contagious, yet both its proximate mechanism(s) and its ultimate causation remain poorly understood. Scholars have suggested a link between contagious yawning (CY) and sociality due to its appearance in mostly social species. Nevertheless, as findings are inconsistent, CY’s function and evolution remains heavily debated. One way to understand the evolution of CY is by studying it in hominids. Although CY has been found in chimpanzees and bonobos, but is absent in gorillas, data on orangutans are missing despite them being the least social hominid. Orangutans are thus interesting for understanding CY’s phylogeny. Here, we experimentally tested whether orangutans yawn contagiously in response to videos of conspecifics yawning. Furthermore, we investigated whether CY was affected by familiarity with the yawning individual (i.e. a familiar or unfamiliar conspecific and a 3D orangutan avatar). In 700 trials across 8 individuals, we found that orangutans are more likely to yawn in response to yawn videos compared to control videos of conspecifics, but not to yawn videos of the avatar. Interestingly, CY occurred regardless of whether a conspecific was familiar or unfamiliar. We conclude that CY was likely already present in the last common ancestor of humans and great apes, though more converging evidence is needed.
Collapse
Affiliation(s)
- Evy van Berlo
- Institute of Psychology, Cognitive Psychology Unit, Leiden University, Leiden, The Netherlands. .,Leiden Institute for Brain and Cognition (LIBC), Leiden, The Netherlands.
| | - Alejandra P Díaz-Loyo
- Laboratorio de Ecología de La Conducta, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Oscar E Juárez-Mora
- Laboratorio de Ecología de La Conducta, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Mariska E Kret
- Institute of Psychology, Cognitive Psychology Unit, Leiden University, Leiden, The Netherlands.,Leiden Institute for Brain and Cognition (LIBC), Leiden, The Netherlands
| | - Jorg J M Massen
- Department of Biology, Animal Ecology Group, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
14
|
Fröhlich M, Kunz J, Fryns C, Falkner S, Rukmana E, Schuppli M, Knief U, Utami Atmoko SS, Schuppli C, van Noordwijk MA. Social interactions and interaction partners in infant orang-utans of two wild populations. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
15
|
Roth TS, Rianti P, Fredriksson GM, Wich SA, Nowak MG. Grouping behavior of Sumatran orangutans (Pongo abelii) and Tapanuli orangutans (Pongo tapanuliensis) living in forest with low fruit abundance. Am J Primatol 2020; 82:e23123. [PMID: 32187394 PMCID: PMC7317506 DOI: 10.1002/ajp.23123] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 03/03/2020] [Accepted: 03/06/2020] [Indexed: 11/05/2022]
Abstract
In contrast to the African great apes, orangutans (Pongo spp.) are semisolitary: Individuals are often on their own, but form aggregations more often than expected by chance. These temporary aggregations provide social benefits such as mating opportunities. When fruit availability is high, costs of aggregating should be lower, because competition is less pronounced. Therefore, average party size is expected to be higher when fruit availability is high. This hypothesis would also explain why orangutans in highly fruit-productive habitats on Sumatra are more gregarious than in the usually less productive habitats of Borneo. Here, we describe the aggregation behavior of orangutans in less productive Sumatran habitats (Sikundur and Batang Toru), and compare results with those of previously surveyed field sites. 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. With regard to between-site comparisons, average party sizes of females and alone time of parous females in Sikundur and Batang Toru were substantially lower than those for two previously surveyed Sumatran sites, and both fall in the range of values for Bornean sites. Our results indicate that the assessment of orangutans on Sumatra as being more social than those on Borneo needs revision. Instead, between-site differences in sociality seem to reflect differences in average fruit availability.
Collapse
Affiliation(s)
- Tom S Roth
- Animal Ecology, Utrecht University, Utrecht, The Netherlands
| | - Puji Rianti
- Department of Biology, Faculty of Mathematics and Natural Sciences, IPB University (Bogor Agricultural University), Bogor, Indonesia
| | - Gabriella M Fredriksson
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Serge A Wich
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.,School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Matthew G Nowak
- Sumatran Orangutan Conservation Programme, The PanEco Foundation, Berg am Irchel, Switzerland.,Department of Anthropology, Southern Illinois University, Carbondale, Illinois
| |
Collapse
|