ORIGINAL PAPER Does the risk of encountering lions influence African herbivore behaviour at waterholes? Marion Valeix & Hervé Fritz & Andrew J. Loveridge & Zeke Davidson & Jane E. Hunt & Felix Murindagomo & David W. Macdonald Received: 24 November 2008 / Revised: 18 February 2009 / Accepted: 12 March 2009 / Published online: 31 March 2009 # Springer-Verlag 2009 Abstract A central question in the study of predator–prey relationships is to what extent prey behaviour is determined by avoidance of predators. Here, we test whether the long- term risk of encountering lions and the presence of lions in the vicinity influence the behaviour of large African herbivores at waterholes through avoidance of high-risk areas, increases in group size, changes in temporal niche or changes in the time spent in waterhole areas. In Hwange National Park, Zimbabwe, we monitored waterholes to study the behaviour of nine herbivore species under different risks of encountering lions. We radio-collared 26 lions in the study area which provided the opportunity to monitor whether lions were present during observation sessions and to map longer-term seasonal landscapes of risk of encountering lions. Our results show that the preferred prey species for lions (buffalo, kudu and giraffe) avoided risky waterholes. Group size increased as encounter risk increased for only two species (wildebeest and zebra), but this effect was not strong. Interestingly, buffalo avoided the hours of the day which are dangerous when the long-term and short-term risks of encountering lions were high, and all species showed avoidance of waterhole use at night times when lions were in the vicinity. This illustrates well how prey can make temporal adjustments to avoid dangerous periods coinciding with predator hunting. Addi- tionally, many herbivores spent more time accessing water to drink when the long- and short-term risks of encounter- ing lions were high, and they showed longer potential drinking time when the long-term risk of encountering lions was high, suggesting higher levels of vigilance. This study illustrates the diversity of behavioural adjustments to the risk of encountering a predator and how prey respond differently to temporal variations in this risk. Keywords Buffalo . Hwange National Park . Landscape of risk . Predation risk . Predator–prey relationships . Temporal niche Introduction To reduce the risk of predation, prey make behavioural decisions to decrease the probabilities of encounter, attack and capture, and the time spent vulnerable to predation (Lima and Dill 1990). The two major and most studied behavioural adjustments are group formation and vigilance (Lima 1995; Roberts 1996). Indeed, compared to solitary animals, individuals within a group benefit from not only the greater number of individuals available to scan the surroundings and thus to detect an approaching predator Behav Ecol Sociobiol (2009) 63:1483–1494 DOI 10.1007/s00265-009-0760-3 Communicated by M. Festa-Bianchet M. Valeix : A. J. Loveridge : Z. Davidson : J. E. Hunt : D. W. Macdonald Wildlife Conservation Research Unit, Zoology Department, Oxford University, Tubney House, Abingdon OX13 5QL, UK F. Murindagomo Zimbabwe Parks and Wildlife Management Authority, P.O. Box CY140, Causeway, Harare, Zimbabwe M. Valeix (*) : H. Fritz Université de Lyon, CNRS Université Claude Bernard Lyon 1 UMR 5558, Laboratoire Biométrie et Biologie Evolutive, Bât Gregor Mendel 43 Bd du 11 novembre 1918, 69622 Villeurbanne cedex, France e-mail: mvaleix@yahoo.fr