January 30, 2023

A long-tailed weasel crosses the snow. Long-tailed weasels turn white in winter except for a black tip on their tail.
Richard Seeley/Get Wild

Summit County looks great in its new coating of fresh white snow! In winter, we can enjoy falling snowflakes, gliding skis, and gleaming white mountains contrasting against our beautiful blue skies. As we watch the falling snow, some of our year-round residents color to match the white: ptarmigans, snowshoe hares, and two species of weasels. This strategy helps predators blend in with the snow and sneak up on their prey, and helps herbivores hide from their predators.

Above the tree line in our mountains lives the elusive little ptarmigan, Lagopus leucura, the smallest member of the ptarmigan family in North America. Famous for blending in with the tundra in both summer and winter, ptarmigans are the only birds in the world that turn white in winter. Their winter colors are pure white except for the dark eye and beak. Fluffy white feathers even cover their feet, keeping them warm and like snowshoes. With the spring snowmelt, ptarmigans gradually replace winter feathers with mottled light and dark browns, and mingle with summery tundra rocks and plants while nibbling on plant bits. Their diet consists mainly of buds, leaves and twigs of low-alpine plants. The tail is white year-round, which distinguishes it from other ptarmigan species.

Other ptarmigan species are found further north in Canada and Alaska. The white-tailed ptarmigan also lives in northern and high mountains of the Rocky Mountains down to northern New Mexico. Though ptarmigans are masters at blending in with the tundra, they’re not as common in Colorado as they used to be, likely because so many recreational seekers travel above the tree line. Dogs that are not on a leash are particularly problematic, since ptarmigans are ground nesters.

A snowshoe hare jumps through the snow.
Richard Seeley/Get Wild

The snowshoe hare, Lepus americanus, is a classic Summit County winter mammal, with snowshoe feet ready for snow anytime. Living at high elevations where big feet come in handy year-round, they then acquire a thicker, pure white coat in the winter months for added winter warmth and camouflage. The snowshoe hare can have up to four litters in a year, averaging three to five cubs. Males compete for females, and females can breed with multiple males.

The critically endangered Canada lynx is a major predator of the snowshoe hare, and the population cycles of the two species are closely linked. I’ve seen snowshoe hares in my yard every year for over 20 years, but for the past two years I’ve only seen cottontails. Unfortunately, there is evidence that climate change, which is reducing our snow cover, is leading to a reduction in snowshoe hare populations. Without the protection of deep, long-lasting snow, snowshoe hares are increasingly preyed upon by coyotes, bobcats, and other predators, while our lynx lose their competitive advantage.

The short-tailed weasel, Mustela stoat, and the long-tailed weasel, Neogale frenata, both belong to the family Mustelidae, or weasels. Known to be fierce predators, these tiny weasels typically attack much larger animals. Extremely fast and efficient predators, they can jump quite high and pounce on their prey from under the snow. Unlike ptarmigan and snowshoe hare, these weasels retain a black tip of their tail. Why? This wildly whipping black tip is believed to distract predators. Weasels are quite elegant animals and are fun to watch during our Summit winters. They move so fast, but that black tip catches the eye. I had the pleasure of seeing an ermine last winter, right out my back door after catching a chipmunk in its mouth.

While admiring our magnificent white mountains, you might also be lucky enough to spot one of our masterful white camouflage suits nearby.

Karn Stiegelmeier is the Chairman-elect of the Eagle Summit Wilderness Alliance, an all-volunteer nonprofit organization that helps the US Forest Service protect and conserve wilderness areas in Eagle and Summit counties. For more information visit EagleSummitWilderness.org

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