Apocrine sweat glands produce the cheek markings which are used to demarcate territories and attract potential mates.

The other form of communication for American pikas is scent-marking with cheek glands.

A pika will make a shrill call of warning and dive into its burrow when threatened by predators and so is known as the ‘whistling hare’.

This behavior modifies its habitat and thus has earned this animal the label of ‘ecosystem engineer’.

The America pika has two very different strategies for foraging: immediately eating the food it finds, and haying - the collecting and storing of food in piles in crevices or on rocks.

They collect a pile of grasses and wildflowers and spread them out to dry in the sun so they will not get moldy, then store them in their den until winter. To prepare for winter, when there are not so many grasses and flowers to be found in the mountains, pikas save food during the summer.

American pikas are well-prepared animals.

Aside from rushing to and fro from their territory seeking food, American pikas spend much of their time sitting still, observing their surroundings, and watching out for predators such as weasels, coyotes, martens, and stoats.

Pikas are thought to have evolved from an animal from Siberia that crossed to North America over the land bridge that used to exist between Asia and Alaska.

Currently, this species is classified as Least Concern (LC) however, its numbers today are decreasing. There are no estimates of population numbers for American pika.

As it has adapted to living in mountainous areas that are not often above freezing temperatures, it can die even after only a few hours of exposure to temperatures like 78 degrees F. As temperatures rise, animals living in the mountains may move higher to find suitable habitat but this option is not open to the American pika, as it already lives so high up. This species is particularly vulnerable to this danger, as its habitat is the cool, relatively moist alpine climate. A study carried out from 1994 to 1999 found that 7 out of 25 American pika populations that were monitored had become extinct, partly due to climate change. The major threat to American pikas is global climate change, this species being in line to become the first North American mammal to be a victim of this threat. Their call sounds like a bleating lamb, but squeakier and more high-pitched. You will often hear a pika before you can see it, as they call and sing to define or protect their territory, warn others of danger and attract mates. They eat stored grasses and venture out to forage if the weather permits. In winter they tend to spend most of their time inside the den. These tiny animals are active during the daytime and do not hibernate in winter, being active throughout the year. However, they can enlarge their homes by digging. They rely on existing spaces in the talus for homes and do not dig burrows. Pikas usually have their den and nest sites below rock around 0.2-1 m in diameter, but often sit on larger and more prominent rocks. An individual will make territorial calls to define its boundaries with its neighbor.

Although this species lives in colonies, they are extremely territorial over the den and surrounding area. They live close to other pikas and they will alert the group about predators by giving a warning call. These animals help protect themselves through their life in colonies. American pikas are adapted to very inhospitable environments, living where most other mammals avoid going - the treeless slopes on mountains: a very rocky, cold, and treacherous habitat for the tiny pika.

Pika mouse