Behaviour of a large ungulate reflects temporal patterns of predation risk

Abstract

Context Many prey species exhibit antipredator behaviours when threatened, yet prey response to temporal variation in predation risk is not well-understood, despite being foundational to predator–prey dynamics and an important consideration among game population managers and recreationalists. Aims To examine white-tailed deer (Odocoileus virginianus) behaviour in response to temporal variation in predation risk imposed by recreational hunters and to assess the effect of deer sex and age on antipredator response. Methods Global positioning system (GPS) collars were used to monitor behaviour of female and male deer in response to diel and weekly patterns of recreational hunting in Alabama, USA. Key results Deer behaviour on weekends (i.e. Friday–Sunday), corresponding to periods of elevated risk, was similar to behaviour on weekdays (i.e. Monday–Thursday). However, when behaviour was examined by individual day of the week, movement rate decreased by 17%, net displacement decreased by 31%, and the probability of activity decreased by 24% during daylight hours on Sundays compared with Fridays. Behavioural changes among days were not detected at night. Daytime behavioural shifts persisted until Wednesdays, despite lower weekday hunting activity. Behavioural variation by deer sex and age was also observed. Conclusions Deer perceive temporal variation in predation risk and modify their behaviour to reduce the likelihood of predation. Variation in response across sex and age classes may be driven by previous experience with hunters and/or survival- and fitness-related trade-offs that affect prey decisions at the individual level. Antipredator response was not initially detectable when examined at a broad temporal scale (i.e. weekend vs weekday); however, a behavioural response was shown with a finer-scale analysis (i.e. individual day of the week), which more closely reflected the pattern of risk fluctuation. Implications Our findings demonstrated the acute awareness of a large ungulate to temporal changes in predation risk and provided insight into ways in which these prey behaviourally respond to reduce the likelihood of predatory encounters. Future studies should consider the temporal scale of risk fluctuation when examining antipredator response to avoid false conclusions. Ungulate hunters and managers can use this information to more efficiently achieve their goals.