Climatic conditions worldwide are changing rapidly, from precipitation regimes to increasing surface temperatures. Acclimatization, most effectively achieved through behavioral modifications, is often an individual’s first line of defense in response to rapid environmental change. Understanding the degree to which animals can acclimatize to hot temperatures contributes to the understanding of each species’ vulnerability to climate change. However, most behavioral plasticity studies are focused on single species in a single ecosystem. This lack of meta-analyses reduces our ability to quantify different species’ behavioral responses, limiting our understanding of which species are more or less plastic in the face of climate change and why. Using GPS collar data from ten species of large mammals in the Rocky Mountains, I quantified the extent to which animals modified their movement and habitat selection (i.e., behavioral plasticity) when faced with hot temperatures. I assessed habitat selection over a spectrum of temperatures during summer days using a resource selection function (RSF). I used a suite of abiotic attributes that influence thermoregulation and are consistently available across a large study area: elevation, aspect, percent cover, and soil moisture. Simple movement models were used to determine if movement characteristics (a surrogate for energy expenditure) were influenced by temperature.
Results/Conclusions
Variation in temperature clearly influences daytime resource selection, although heat mitigation strategies and the magnitude of behavioral plasticity varied across populations. For instance, bison selected areas that had higher soil moisture content on hot days relative to baseline selection, while elk tended to move to northerly slopes. Characteristics of a population’s physical environment also influenced how they behaviorally mitigated heat stress. Moose with readily available thermal cover tended to use northerly slopes while their conspecifics in open, exposed environments sought out the little cover that was available. In addition, there appears to be substantial individual variation in strategies for mitigating heat stress. This research helps to fill a gap in knowledge regarding which species demonstrate higher levels of behavioral plasticity in the face of rapid climate change. Wildlife managers can then use this information to decide which species and landscape features to focus on for conservation efforts, given limited resources. Furthermore, my multi-taxa approach may shed light on ecological and evolutionary factors that facilitate or constrain a species’ ability to behaviorally mitigate heat stress.