Risk-Taking in Samango Monkeys in Relation to Humans at Two Sites in South Africa

  • Katarzyna Nowak
  • Russell A. Hill
  • Kirsten Wimberger
  • Aliza le Roux
Part of the Developments in Primatology: Progress and Prospects book series (DIPR)


A fundamental step in the management and conservation of wild species is advancing our understanding of how animals perceive and use their habitat. Spatial variation in risk either from natural predation or human disturbance generates a “landscape of fear” that can be measured and assessed using experimental patch approaches such as giving-up densities (GUDs). For primates inhabiting a matrix of human habitation, exotic plantations, and indigenous forest, it is possible to explore the “risk-disturbance hypothesis,” which posits that human risk parallels natural predation risk in its effects on animals’ habitat use and decision-making. Here we report on a combination of studies on arboreal samango monkeys (Cercopithecus albogularis spp.) and their risk-sensitive foraging at two sites subject to varying anthropogenic pressures. Using GUDs experiments, we documented pronounced effects of humans on monkeys’ patch use but the impact of humans did not simplistically follow predictions from the risk-disturbance hypothesis. At a site with limited human infrastructure, monkeys exploited food patches at typically high-risk strata (ground level) more intensively in the presence of researchers, whom they likely perceived as shields against terrestrial predators (leopards Panthera pardus, caracals Caracal caracal). Meanwhile, at a predator-poor site where monkeys regularly came into contact with human infrastructure and gardens (adjacent to indigenous forest), the experiments indicated that monkeys preferred to forage in indigenous forest given experimental patches in both forest and gardens, where they showed sensitivity to risk (likely from both humans and domestic dogs Canis lupus familiaris). However, once already in gardens, monkeys depleted patches to extents similar to inside indigenous forest. In this chapter, we also elaborate on monkeys’ risk-sensitive responses to negative, neutral, and rewarding objects associated with humans, and explore the impact of prior experience on risk-taking behavior in proximity to humans and their infrastructure. We conclude that the risk-disturbance hypothesis cannot be used as a blanket term to describe primates’ interactions with humans, as we show here how nuanced and flexible samango monkeys’ risk-taking responses are.


Human impacts Risk-disturbance hypothesis Samango monkeys Predator-prey interactions 



K. Nowak was funded by a Durham University COFUND research fellowship, Claude Leon Foundation postdoctoral grant, and the R. W. Primate Fund during the course of this research. Fieldwork at Lajuma was supported by an Earthwatch grant to R. Hill. A. le Roux was supported, in part, by incentive funding for rated researchers by the National Research Foundation. K. Wimberger was supported by the Claude Leon Foundation, UCT URC Fellowship, JMasters NRF Fund, Novartis SAVF Wildlife Research Fund, Primate Conservation Inc., and Mazda Wildlife Fund during her research in Hogsback. We thank Ian Gaigher and the Primate and Predator Project (PPP) team in Lajuma, and Steve Boyes in Hogsback for logistical support and assistance in the field. We are especially grateful to Ciska Scheijen, Alison Midgley, Diana Breshears, Nthabiseng Mathibane, and PPP for assisting with GUDs experiments in the field. We also thank the community of Hogsback for allowing us to run experiments in their gardens. Shane Richards advised on models in R. Ethical approval came from Durham University’s Life Sciences Ethical Review Process Committee and from the University of the Free State’s Inter-Faculty Animal Ethics Committee. Research permission was granted to K. N. by the Department of Economic Development, Environmental Affairs and Tourism and by the Department of Water Affairs and Forestry.


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Katarzyna Nowak
    • 1
    • 2
  • Russell A. Hill
    • 1
    • 3
  • Kirsten Wimberger
    • 4
  • Aliza le Roux
    • 2
  1. 1.Evolutionary Anthropology Research Group, Department of AnthropologyDurham UniversityDurhamUK
  2. 2.Department of Zoology and EntomologyUniversity of the Free StatePhuthaditjhabaSouth Africa
  3. 3.Primate & Predator Project, Lajuma Research CentreMakhadoSouth Africa
  4. 4.Department of Biological SciencesUniversity of Cape TownCape TownSouth Africa

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