Grand Teton National Park Foundation

Wildlife Whereabouts: Heavy Snowfall Impacts Animals in Grand Teton National Park

Friday, February 24th, 2017

Record snow depths in both the mountains and valley have brought many deer, elk, and moose to the lowest elevations of the park and Jackson Hole. Many of these animals are not used to being in such close proximity to people, which can add considerable stress and lower fitness. Please consider the space and energy conservation needs of wildlife during winter and don't approach them closely, even though they may appear unconcerned. In many cases, they simply have nowhere else to go until snow depths decrease and will need every last minute of peace and quiet we can give them to survive the winter.

Otters are well adapted to a life in and out of cold water with thick, protective fur that helps them keep warm. Photo courtesy of Ryan Sheets.

• By late February, bull moose have dropped their antlers. To tell the difference between males and females, look for the antler attachment points, called pedicles, on the heads of males or the white fringed area around the tail on females.

• It’s nearing the end of the wolf breeding season. Similar to dogs, the gestation period for wolves is 63 days. Females will whelp pups in mid-to-late April, but the pups will not emerge from dens until May.

• Long-tailed weasels are crust cruising and leaving behind tell-tale signs of their activities — dumbbell shaped tracks zig-zagging across the snow's surface and small holes that plunge to the subnivean environment where they find prey.

• Sage grouse, which are year-round residents that survive the winter by foraging on sagebrush leaves exposed above the snow, will begin their courtship at lek sites in late March and April.

• Mule deer that summer in the northern portions of Grand Teton are on their winter ranges in the North and South Forks of the Shoshone River near Cody, around Dubois, Wyoming, in Idaho's Teton Canyon, and near Farson, Wyoming to the south. Some animals, like mule deer, migrate long distances to avoid the harsh winter conditions encountered in Jackson Hole and to find more accessible foods where snow cover is reduced.

• During mid-winter, vegetation can be exposed on southern aspects where trees radiate warmth, causing the snow around the base of the tree to melt, and in avalanche paths when the snow slides to ground level. Resident mule deer will move from tree well to tree well and to avalanche areas to take advantage of the available browse.

• As days gradually lengthen, ravens, bald eagles, and great-horned owls — some of the area's earliest nesters — begin courtship activities.

• Pronghorn are poorly adapted to deep snow and the typical extreme winter conditions of Jackson Hole. Most of the 300 or so animals that summer here migrate to the Green River drainage south and east of Jackson Hole to winter, where snow is not as deep.

• River otters are active near water bodies all winter using holes in the ice to move between land and water. Otters are well adapted to a life in and out of cold water with thick, protective fur that helps them keep warm. Because of their short legs, webbed feet, and sleek bodies they are strong swimmers.

• As the snowpack continues to grow in the mountains, it is looking like the valley will experience a greater than average runoff, which often bodes well for fish. Bigger water years are usually favorable for cutthroat reproduction.

• Cutthroat typically spawn just after peak in runoff, larger snowpacks often translate into later spawning runs and greater young of the year survivorship.

• Better than average recruitment usually translates into increased fisherman success a few years later as the year class reaches 3-4 years old and the fish grow in excess of 12 inches.