Safety first : seasonal and diel habitat selection patterns by red deer in a contrasted landscape

Abstract

Spatially heterogeneous landscapes provide solutions to the forage-safety trade-off when animals can access risky but energetically rewarding patches, or safer but resource-poor patches. It can be advantageous for an animal to secure access to habitat heterogeneity at a broader scale in order to be able to dynamically adjust finer scale habitat use through time. We tested the hypothesis of a forage-safety trade-off optimization tactic in a hunted red deer (Cervus elaphus) population fol- lowing a large accidental forest fire. We used telemetry data and fitted resource selection functions at the second- and third-order scales. We then integrated the order-specific probabilities into single, all-in-one multi-level layers that synthetically captured the habitat selection patterns across scales by informing landscape-scale annual habitat selectivity with finer within-home-range seasonal and diel processes. At the landscape scale, red deer anchored their home-range at the interface of the disturbed and undisturbed patches, thereby securing habitat heterogeneity. This con- sequently enabled them to modulate within-home-range habitat selection depending on the season and the time of the day. In both seasons, red deer consistently used the burnt area for cover more during the day, and foraged in the unburnt forest and open fields at night. Interestingly there were no major seasonal differences in this diel habitat selection patterns. Increased mortality risk during the hunting sea- son did not substantially change their spatial behaviour. We conclude that year- round avoidance of non-lethal human disturbance is the main driver of red deer habitat use in this system.