Temporal variation in habitat selection breaks the catch-22 of spatially contrasting predation risk from multiple predators

Predator avoidance depends on prey being able to discern how risk varies in space and time, but this is made considerably
more complicated if risk is simultaneously present from multiple predators. Th is is the situation for an increasing number
of mammalian prey species, as large carnivores recover or are reintroduced in ecosystems on several continents. Roe deer
Capreolus capreolus in southern Norway illustrate a case in which prey face two predators with contrasting patterns of
predation risk. Th ey face a catch-22 situation: spatially avoiding the risk from one predator (lynx Lynx lynx in dense habitat)
implies exposure to the other (hunters in open habitat). Using GPS-data from 29 roe deer, we tested for daily and seasonal
variation in roe deer selection for habitat with respect to the habitats ’ year-round average risk level. Generally, roe deer
altered their habitat selection between night and day in a pattern consistent with being able to avoid predicted risk from
the nocturnal lynx during night and predicted risk from human hunters during day. However, seasonal variation in habitat
selection only partially corresponded with the predicted seasonal variation in risk. Whereas roe deer avoided areas with
high risk from hunters more strongly during the hunting season than in other seasons, there was a lack of selection towards
areas and time periods lowering the risk of lynx predation during winter. It seems likely that the risk of starvation and
thermal stress constrain roe deer habitat selection during this energetically challenging season with cold temperatures, snow
cover and limited natural forage. Th e habitat selection pattern of roe deer fi ts thus only partly with the two contrasting
risk gradients they face. Adjusting risk-avoidance behavior temporally can be an adaptive response in the case of several
predators whose predation patterns diff er in space and time.