Disentangling risk in a multi-predator landscape : roe deer respond to differing patterns of risk to lynx, wolves and humans through shifts in their habitat selection

Sammanfattning: Predation risk is known to evoke behavioural responses in prey animals, and prey are often faced with a trade-off between lowering their risk to predation and acquiring resources. This situation becomes more complex in a multi-predator landscape, especially if those predators employ different hunting strategies, and induce different spatial patterns of risk. In this study, the spatial patterns of predation risk that roe deer face from humans, as well as their natural predators, lynx and wolves, were identified. Using the natural experiment provided by the return of large predators and the coinciding decline in hunting mortality, the behavioural responses of roe deer to shifting patterns of predation risk were examined. Using predation and hunting mortality locations, combined with used locations from the same 149 roe deer, predation risk to each predator was related to habitat and infrastructure attributes. Mostly in line with predictions, agricultural lands were found to present the highest risk to human hunting, while old forest provided a safe habitat from lynx predation, and no strong pattern was found for wolf predation. Habitat selection in relation to the most important risk factors was then compared between the period before and after lynx recolonized the area, using location data from 231 roe deer individuals. All analyses were conducted at the within home-range scale. I found that in general, agricultural lands were selected for, although less intensively during the hunting season both before and after lynx recolonisation. Moreover, there was a tendency for weaker differences between hunting and non-hunting seasons in the period after the return of lynx, potentially reflecting the lower hunting intensity in that period, and the added risk to lynx in that habitat throughout the year. An increased use of old forest was found after the recolonisation of lynx, potentially due to the relative safety from lynx attack that this habitat provides. Hence, this study demonstrates that different predators can generate different spatial patterns of predation risk, and roe deer seem to respond to these differential patterns through spatial and temporal habitat selection shifts.