The presence of predators on a landscape can have significant impacts on prey behavior. High predation can affect prey composition, distribution, and feeding. In areas open to public hunting, humans can influence animals in a similar manner to native predators such as wolves or mountain lions. In the case of elk, an overabundance of predators or humans can negatively impact the health of the herd, as the higher risk of predation leads to nutritional trade-offs.
In a new study from the University of Montana, researchers collared 41 female elk in the Bitterroot Valley to test their hypothesis that elk avoid areas of high human disturbance during archery season. The researchers expected the elk to avoid areas with human traffic, but would this perceived risk translate to reduced nutritional intake?
Risk of predation is thought to drive many ungulate behaviors, but the degree to which fear influences resource selection varies wildly. In the well known Yellowstone Wolf-Elk study, the re-introduction of wolves created a ‘landscape of fear’ which drove the elk from their riparian feeding grounds. This resulted in the cottonwoods and other vegetation rebounding. The study did not research the possible nutritional deficiencies of the elk once they left the cottonwood streams.
The elk studied in the Bitterroot Valley had no mortality due to wolves or cougars during the study period. This allowed the researchers to isolate the effects of humans on the elk herd.
After observing the elk’s behavior for two years, the researchers found the elk were altering their behavior in response to increased human presence. However, they did not flee the hunted area or seek refuge in habitat with lower quality forage. Interestingly, the elk sought denser cover with higher quality forage when hunters entered the landscape. Hunters were actually benefitting the elk’s foraging strategies.
Many variables come into play with this particular study that may make it difficult to replicate the methods with other elk herds. Most notably the lack of native predators, but the elk’s unwillingness to leave good food in the face of increased predation risk is hopeful. It is also possible this particular elk herd is more comfortable with human influence as the Bitterroot Valley is a popular tourist destination. Still, if the study is replicated in other settings the future of elk populations and elk hunting looks bright.