Stacy Lindshield1,2, Brent J Danielson2,3, Jessica M Rothman4,5, Jill D Pruetz1,2. 1. Department of World Languages and Cultures, Iowa State University, Ames, Iowa. 2. Ecology and Evolutionary Biology Program, Iowa State University, Ames, Iowa. 3. Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa. 4. Department of Anthropology, Hunter College of the City University of New York. 5. New York Consortium in Evolutionary Primatology, New York.
Abstract
OBJECTIVES: We evaluated risk-sensitive foraging in adult male western chimpanzees (Pan troglodytes verus) occupying a savanna environment at Fongoli, Senegal. The aim of this study was to determine how the risks of predation and heat stress influenced their behavior while feeding on a key food, fruit of the baobab tree (Adansonia digitata). MATERIALS AND METHODS: Proximity of fruiting baobab trees to anthropogenic landmarks were compared to food intake, feeding rate, and behavioral indicators of fear in adult males (N = 11) at Fongoli. Additionally, we compared foraging to vegetative habitats, baobab ripe fruit nutritive quality, surface water availability, and foraging party composition. RESULTS: Fruit abundance increased with proximity to anthropogenic landmarks, and chimpanzees exhibited higher frequencies of antipredator behaviors as they approached these risky areas. However, predation risk did not deter adult males from visiting these fruiting trees; instead, risky foraging bouts were associated with higher food intakes and longer feeding times. Additionally, higher feeding rates were observed in open-canopy habitats, and this behavior may have minimized their risk of heat stress. CONCLUSIONS: Adaptations that minimize predation risk are widespread in mammalian prey species, but these traits are poorly understood in chimpanzees. Great apes encounter few nonhuman predators capable of successfully capturing and killing them; thus, such events are rarely observed. Although people rarely hunt chimpanzees in Senegal, we found that adult males perceived humans as predators and adjusted their behavior while foraging in risky habitats. From an applied perspective, risk-taking behavior is important for understanding and mitigating the problem of crop-feeding in locations where chimpanzees and humans live in sympatry.
OBJECTIVES: We evaluated risk-sensitive foraging in adult male western chimpanzees (Pan troglodytes verus) occupying a savanna environment at Fongoli, Senegal. The aim of this study was to determine how the risks of predation and heat stress influenced their behavior while feeding on a key food, fruit of the baobab tree (Adansonia digitata). MATERIALS AND METHODS: Proximity of fruiting baobab trees to anthropogenic landmarks were compared to food intake, feeding rate, and behavioral indicators of fear in adult males (N = 11) at Fongoli. Additionally, we compared foraging to vegetative habitats, baobab ripe fruit nutritive quality, surface water availability, and foraging party composition. RESULTS: Fruit abundance increased with proximity to anthropogenic landmarks, and chimpanzees exhibited higher frequencies of antipredator behaviors as they approached these risky areas. However, predation risk did not deter adult males from visiting these fruiting trees; instead, risky foraging bouts were associated with higher food intakes and longer feeding times. Additionally, higher feeding rates were observed in open-canopy habitats, and this behavior may have minimized their risk of heat stress. CONCLUSIONS: Adaptations that minimize predation risk are widespread in mammalian prey species, but these traits are poorly understood in chimpanzees. Great apes encounter few nonhuman predators capable of successfully capturing and killing them; thus, such events are rarely observed. Although people rarely hunt chimpanzees in Senegal, we found that adult males perceived humans as predators and adjusted their behavior while foraging in risky habitats. From an applied perspective, risk-taking behavior is important for understanding and mitigating the problem of crop-feeding in locations where chimpanzees and humans live in sympatry.
Authors: Moreen Uwimbabazi; David Raubenheimer; Mnason Tweheyo; Gilbert I Basuta; Nancy L Conklin-Brittain; Richard W Wrangham; Jessica M Rothman Journal: Am J Primatol Date: 2021-05-18 Impact factor: 3.014
Authors: Adam van Casteren; Vicky M Oelze; Samuel Angedakin; Ammie K Kalan; Mohamed Kambi; Christophe Boesch; Hjalmar S Kühl; Kevin E Langergraber; Alexander K Piel; Fiona A Stewart; Kornelius Kupczik Journal: Commun Biol Date: 2018-08-10