Use of multiobjective optimization models to examine behavioural trade-offs of white-tailed deer habitat use in forest harvesting experiments

Abstract

I evaluated the habitat use of white-tailed deer (Odocoileus virginianus Zimmermann) in a boreal mixedwood forest managed for timber production in northern Saskatchewan, Canada, to determine which kinds of factors (e.g., forage abundance, canopy cover) influenced habitat use, if white-tailed deer considered these habitat factors in isolation or instead there was evidence of trade-offs, and whether the identification of the factors or the way in which they were traded off varied subsequent to the introduction of harvested patches or changes in hunting traffic. Habitat use was estimated through ground-based surveys before and after the elimination of hunting traffic in a partially harvested site and before and after harvesting in a formerly hunted but unharvested site. Forage abundance was always a significant, or marginally significant, predictor of habitat use. Canopy cover was only important in sites with limited water access. In the presence of hunting traffic, white-tailed deer balanced multiple habitat factors (e.g., food access vs. road avoidance); when hunting traffic was eliminated, the trade-off behaviour was abandoned. The variety in behaviour that the white-tailed deer exhibited in my study implies that to successfully protect habitat, it may not be sufficient to simply identify the factors that influence habitat use (and presumably value). We may also need to understand how the animals deal with these factors under different conditions.