Pikas are one of the cutest of our mountain animals. How do they survive life in the high talus slopes, in steep piles of jumbled rock and beneath cliffs in the high mountains in the winter? These bare rocks seem like very inhospitable habitats, yet it is their home, pantry and shelter.

The talus fields which pika colonies inhabit are generally fringed by suitable vegetation. Pikas usually have their den and nest sites below rocks, but often sit on larger and more prominent rocks. They generally reside in scree near or above the tree line.

Pikas keep it cool

American pikas live at very high altitudes because they cannot tolerate heat. They avoid hot weather by seeking out the cool crevices under boulders, and by remaining inactive during warm periods. During the cold, snowy winters at high elevations, they are protected by their dense coat of fur. The dorsal fur of the pika ranges from grayish to cinnamon-brown, with tawny hues during the summer. During winter, the fur becomes grayer and longer. The dense under-fur is usually slate-gray or lead colored.

The closest relative to the Pika, is the rabbit, and they run a little like rabbits, but they have small, round ears and no tail. While their marmot neighbors are hibernating, these little creatures remain active beneath the snow in the talus slope. A deep layer of snow protects pikas from high winds, and temperatures below –20 F, but if the snow is shallow, pikas may die of exposure. I hope this winter was not too harsh on our local pikas.

Putting up hay

In preparing for winter, pikas dig tunnels in the snow from their den areas to the hay piles. On bright sunny days when the weather is bitterly cold and other animals are either hibernating or hiding in dens, pikas can be found sunning themselves on exposed rocks.

Summer, spring and fall are only a few months long in the high-alpine environment. In that time pikas are furiously busy cutting grass and flowers and adding them to their hay stacks. To survive seven months of winter, pikas cache summer vegetation in a hay pile sheltered beneath a large rock within their territory.

A pika makes an estimated 14,000 collecting trips during the short mountain summer to accumulate the hay pile. When the hay pile is gone, a pika will gnaw lichens from the rocks.

Some pika hay piles can be spotted easily, others are hard to find. Pikas often tuck their loads under large overhanging rocks or sometimes make huge bushel piles of hay right on the talus surface. Other pikas wedge their hay between rocks, so very little of even a large hay pile is visible on the surface.

Pikas save their winter larder in a very methodical way in a stack that often measures several feet thick and contains some 60 pounds of vegetation. Pikas first gather fresh vegetation and lay it in stacks to dry. Once the plants and grasses dry out, the pikas take this hay back to the burrows for storage. They must literally make hay while the sun shines, storing vegetation for winter feeding.

After cutting a columbine stalk with its teeth, a pika grips the plant between its jaws and runs to add it to a hay pile. Earlier in the season pikas eat the columbine's flowers but ignore the rest of the plant which is toxic. Pikas choose some plants for their anti-bacterial properties which keeps the hay pile from rotting.

Pikas can literally mow down plants, turning their heads to the side to bite off stems as close to the ground as possible. They have been observed harvesting and carrying off 4-foot-tall stalks of mountain bluebells, only to have their scampering retreat across the talus abruptly halted as the long stems wedge between rocks.

The hay piles also form the basis of interesting social interactions with the rest of the colony. For much of the year pikas are very territorial, and their territories are centered on their hay piles. There is an endless turf battle. Pikas throughout the colony are constantly running others off from their territory. Frequently pikas must cross other pika's home areas to get to spots where plants grow, so it is a never ending skirmish.

The protection of territory continues into the winter when pikas guard their hay stacks. In the spring there seems to be a truce and pikas are suddenly open to sharing their hay stacks. Coincidentally, it is about the same time that pikas are starting to look for mates. This hospitality ends at about the time that mates are selected.

Pikas are in a constant race with winter. Babies are born in spring, weaned in three weeks, and then immediately kicked out of mom's territory. In order to survive they must then hurry to establish their own territories and accumulate a hay pile for the impending winter.

The term “making hay” refers to being highly productive for a limited period of time when the opportunity is present. Pikas are probably the littlest, cutest “hay makers” and they really make hay!

Dr. Joanne Stolen is retired from teaching microbiology at Rutgers University.