African ungulates and their drinking problems: hunting and predation risks constrain access to water William-Georges Crosmary a, b, c, * , Marion Valeix a , Hervé Fritz a , Hillary Madzikanda d , Steeve D. Côté b a Université de Lyon, CNRS Université Claude Bernard Lyon, Laboratoire Biométrie et Biologie Evolutive, Bât Gregor Mendel, Villeurbanne, France b Département de Biologie, Pavillon Alexandre-Vachon, Université Laval, Québec, Canada c CIRAD e EMVT, Integrated Wildlife Management Research Unit, Campus International de Baillarguet, Montpellier, France d Zimbabwe Parks and Wildlife Management Authority, Causeway, Harare, Zimbabwe article info Article history: Received 27 April 2011 Initial acceptance 23 May 2011 Final acceptance 28 September 2011 Available online 16 November 2011 MS. number: A11-00345R Keywords: behavioural adjustment ecology of fear hunting risk predation risk ungulate waterhole Prey make several behavioural adjustments to minimize the risk of predation by their natural predators. When hunted, however, they may have to adjust their behaviour further or differently to cope with this additional mortality risk. Here, we investigated whether African large ungulates would adjust their behaviour in response to hunting risk (i.e. risk of being shot by human hunters). We predicted that they would shift their use of surface water, a key and scarce resource in African savannas, from day hours to night hours to reduce the risk of encountering human hunters. In Hwange National Park, Zimbabwe, we monitored waterholes to record the temporal drinking niche of three nonhunted ungulates (i.e. impala, Aepyceros melampus, greater kudu, Tragelaphus strepsiceros, sable antelope, Hippotragus niger). We also monitored waterholes in hunting areas in the vicinity of Hwange National Park. In Hwange National Park, the three species avoided waterholes at night, when the risk of natural predation was higher. Conversely, in the hunting areas, all three species visited waterholes more often at night. Impala and greater kudu, however, were less prone to switch towards night-time use of waterholes in hunting areas compared to sable antelope, although all three species were exposed to similar hunting risk. Our results suggest that hunting may force African ungulates to shift their visits at waterholes from day hours towards night hours, but that the magnitude of this shift may be constrained by the predation risk imposed by large nocturnal carnivores. We conclude that species preyed upon by natural predators adjust their antipredator behaviour in response to the additional risk of predation imposed by hunting. Ó 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. With ongoing increase of human disturbance on wildlife habitats, there is growing concern about how disturbance stimuli may affect animal behaviour (Geist 1970; Caro 1999a). Animals respond to human disturbance similarly to predation risk, that is, by adjusting their behaviour in order to reduce the disturbance, for example, by increasing flight initiation distance or vigilance, or by shifting habitats (reviewed in Stankowich & Blumstein 2005). There may be medium- to long-term costs associated with behavioural adjustments (e.g. lower resource intake rate, lower diet quality, or decreased mating opportunities; Lima & Dill 1990; Lima 1998). The repercussions of these nonlethal effects of predation or disturbance (sensu Lima 1998) might therefore alter the fitness of individuals, affect population dynamics (Creel et al. 2007; Creel & Christianson 2008), and ultimately community structure and ecosystem functioning (Brown et al. 1999; Ripple & Beschta 2004). Hunting may be considered an extreme type of human distur- bance as individuals from harvested populations experience a direct risk of mortality. Hunting disturbance disrupts normal activities, alters diurnal activity rhythms and increases flight initiation distances in many waterbird species (reviewed in Madsen & Fox 1995). In large ungulates, studies have reported increased flight initiation distance in response to hunting disturbance (reviewed in Stankowich 2008). However, much less is known about long-term behavioural responses such as shifts in habitat use (Swenson 1982) and feeding sites (Benhaiem et al. 2008), or changes in activity patterns (Kufeld et al. 1988). Here we address an example of long-term behavioural adjust- ment to hunting in large game ungulates. We assessed whether ungulates adjust their temporal use of key and scarce resources in response to hunting risk (i.e. risk of being shot by human hunters). A common behavioural response of prey to predation risk is to avoid risky areas where predators are abundant (Ripple & Beschta 2004; Creel et al. 2005; Valeix et al. 2009a). In certain circum- stances, however, spatial avoidance of predators may not be possible, particularly when prey have no choice but to use risky * Correspondence: W.-G. Crosmary, Département de Biologie, Pavillon Alexandre-Vachon, 1045 avenue de la Médecine, Université Laval, Québec, Québec G1V 0A6, Canada. E-mail address: william.crosmary.1@ulaval.ca (W.-G. Crosmary). Contents lists available at SciVerse ScienceDirect Animal Behaviour journal homepage: www.elsevier.com/locate/anbehav 0003-3472/$38.00 Ó 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.anbehav.2011.10.019 Animal Behaviour 83 (2012) 145e153