Zachary Luck wrote:
Near Groundbirch, BC, a small community nestled in the Peace Region, elk hunting is popular practice. As with most ungulates, elk generally move and feed during dawn and dusk. However, during hunting season (late October 2016), it appeared as though a local herd of Rocky Mountain elk (Cervus canadensis nelsoni) had completely adjusted their grazing patterns in response to hunting.
After a few attempts at hunting in the area, we realized that the elk in area refused to leave the denser brush for the nutrient rich feed (alfalfa and hay) in the adjacent farm fields until complete darkness. This was not likely coincidental. Night after night, the elk would wait just beyond the edge of the forested area, seemingly impatient with constant chirping from females and bugling from the dominant male. However, each night, under the cover of complete darkness the elk would confidently wander out into the field mere yards away from us while as we walked back to the truck. There was no uncertainty in my mind, they could smell, hear and probably even see us mere yards away but they knew that under the cover of darkness we were completely harmless.
Tom Okey wrote:
'Optimal foraging theory' would lead us to expect that animals forage in places and at times that reduce their energy expenditures and risk of predation (e.g. Hammerschlag et al. 2010). Elk are known to spend time feeding at night when the daytime temperatures are too high (Merrill 1991), and their nocturnal feeding is known to change "in proportion to the relative length of night" (Green and Bear 1990). Foraging behavior of elk also changes in response to habitat modification such as around natural gas development (Van Dyke et al. 2012).
Although these authors of this published literature have documented the nocturnal and adaptive behavior of elk, I found no published literature indicating that anyone has previously observed elk shifting to nighttime foraging to avoid human hunting risk. The present observation may be the first documented observation of this behavior.
Literature cited
Green, R.A. and Bear, G.D., 1990. Seasonal cycles and daily activity patterns of Rocky Mountain elk. The Journal of wildlife management, pp.272-279.
Hammerschlag, N., Heithaus, M.R. and Serafy, J.E., 2010. Influence of predation risk and food supply on nocturnal fish foraging distributions along a mangrove–seagrass ecotone. Marine Ecology Progress Series, 414, pp.223-235.
Merrill, E.H., 1991. Thermal constraints on use of cover types and activity time of elk. Applied Animal Behaviour Science, 29(1-4), pp.251-267.
Van Dyke, F., A. Fox, S. M. Harju, M. R. Dzialak, L. D. Hayden-Wing, and J. B. Winstead. 2012. Response of Elk to Habitat Modification Near Natural Gas Development. Environmental Management 50:942-955.
.
