High Country Critters
by Dr. Oakleigh Thorne, II High Country Critters
When I talk about the “high country,” I mean the land of high mountain peaks, known as the alpine tundra. It is above timberline (or tree line). In other words, it is above where any tree can grow because of the severe climate up there, especially in the winter months. Spruces and firs are the common tree species at our Colorado timberline. In winter, gritty snow blasted by over 100-mile-an-hour winds will actually remove the branches on the upwind side of a tree, creating what we call a “flag” tree, with all the branches on one side.
Two interesting animals that live in this tundra area are pikas and ptarmigans. Pikas are small furry mammals related to rabbits. Ptarmigans are pheasant-like birds that are in the grouse family.
Pikas are about six inches long and have short, rounded ears and no external tail. They have short limbs and rounded bodies with a soft and even coat of fur like a rabbit. They prefer rocky areas and feed on a variety of plants such as grasses, sedges, forbs, moss, lichens, flowers, and tender stems. They first produce soft green feces that they eat again to gain further nutrition before producing a final solid fecal pellet.
The average lifespan of pikas in the wild is about seven years. One of their nicknames is “whistle pig” because of their high-pitched alarm call given when they dive into their protected rocky burrows.
Sometimes pikas will cut green grass with their gnawing, sharp incisor teeth and then dry it in the sun like hay. They then store this in their burrows along with soft twigs. This is their food supply during the long, cold winter.
Pikas cannot withstand temperatures over 77 degrees F., so they hide in the shade when it is very sunny and hot. With global climate change, this would normally force them to move to a higher altitude, but they are already high up in the tundra, so this may become a serious challenge to their survival in the future.
Like pikas, ptarmigans are also found in the tundra above tree line. Ptarmigans are chicken-like ground-dwelling birds. Ptarmigans have feathered feet and other adaptations for the Arctic/Alpine climate.
In Colorado we have the White-tailed Ptarmigan. They are found in barren, rocky areas. In the summer months they are usually seen singly, but in the winter are often found in small flocks. The male ptarmigan makes a simple croaking sound and other display notes, and both sexes make clucking notes. They are sometimes called “thunderbirds.”
In winter, ptarmigans feed on the catkins and buds of willows, dwarf birch and sometimes aspen. In the spring they will eat various berries and in early summer they will feed on tender leaves, buds, and flowers.
Ptarmigans have three molts each year. In the autumn, they have a complete molt to their wintertime, totally-white plumage, which is good camouflage against the white snow. They are, therefore, often referred to as “white grouse.” In spring they partially molt to their brownish, black-spotted, patterned breeding plumage, but their wings remain white when they fly and there is always white in their tail. The male has red feathers above the eye in summer.
Up in the tundra there are very few predators that would be a threat to ptarmigans, except an occasional Golden Eagle. Ptarmigans, therefore, are usually tame when approached by humans.
I hope you have a chance to someday explore the alpine tundra. Pick a warm summer day free of thunderstorms and hopefully you will get to see both pikas and ptarmigans. They’re cool!
Dr. Thorne is founder and honorary president of Thorne Nature Experience (formerly Thorne Ecological Institute), a nonprofit organization headquartered in Boulder. For 69 years they have helped "connect youth to nature!" For information about their programs, please check their website at www.thornenature.org or email firstname.lastname@example.org or call (303)499-3647, ext. 100.