The first day of the supplemental feed season on the National Elk Refuge was this past Monday. Refuge Senior Biologist Eric Cole explains that in some years, freeze-thaw cycles or a rain event followed by freezing temperatures can cause heavy crusting on the snowpack which makes forage inaccessible although that was not the case this winter.
Jackson Hole has been in a dry, cold cycle for over a month, and undisturbed snowpack has remained fluffy all the way to the ground. However, Cole says when elk move snow with their hooves to gain access to the forage, this causes the snow in the vicinity of where they have been eating to harden.
This hard, dense snow in the vicinity of the foraging site makes remaining grass inaccessible. As of late last week, almost all areas on the south end of the Refuge have been heavily foraged and trampled by elk, resulting in high density snow and little accessible forage.
As of last Sunday, there were approximately 7,200 elk, 120 bison, and 45 bighorn sheep on the south half of the Refuge. Within the first 2 days of supplemental feeding, elk numbers have been relatively stable, but bison numbers increased to 300.
Typically, elk and bison numbers utilizing Refuge feedgrounds continue to increase throughout the month of February. 20-30 pronghorn have also been sporadically observed on the northeast portion of the Refuge.
