PIKAS: Ochotonidae

PHYSICAL CHARACTERISTICS

All pikas (PEE-kuhz) are similar in appearance, being small, compact mammals with large, round ears and short front and rear legs. They resemble guinea pigs in size and appearance, ranging in length from 5 to 12 inches (12.5 to 30.0 centimeters) and weighing 3.5 to 7 ounces (100 to 200 grams). Pikas lack a noticeable tail. They have long, soft fur that is usually gray or brown, often with red accents.

GEOGRAPHIC RANGE

Pikas are found in the mountains of western North America, including Alaska and the Yukon, and the mountains and plains of central Asia, including the Himalayan and Ural mountain ranges. The countries they live in include Iran, Afghanistan, Pakistan, Nepal, Tibet, Bhutan, Russia, Japan, Mongolia, North Korea, and China.

HABITAT

Pikas are found in two distinct habitats. Some live among rocks and rocky areas. Others live in meadows, steppes (semiarid, grass-covered plains), shrubs and desert.

DIET

Pikas are herbivores, meaning they eat primarily plants.

BEHAVIOR AND REPRODUCTION

Pikas are mainly diurnal, active during the day. An exception is the steppe pika, which is nocturnal, meaning it is most active at night. They have several types of social structure. Those that live in rocky areas of North America are unsocial, with males and females having separate territories and rarely interacting except to mate. Pikas in rocky areas of Asia live in pairs within a communal territory. Burrowing pikas, in contrast, are extremely social animals. Families of up to thirty individuals live within burrows and there are about ten family groups within a territory. There is much interaction between family members, including grooming, playing, and sleeping together.

Pikas breed in the spring, with peak breeding occurring in May and early June. Female pikas reach sexual maturity as early as twenty-one days of age. The gestation, or pregnancy, period is about thirty days. Litters consist of one to thirteen babies and are cared for exclusively by the mother. Females breed for a second time shortly after the first litter is born and usually produce a second litter before the end of summer. Some pika species can have as many as five litters per years, including the Afghan pika, with each litter having up to eleven babies. Pikas are born blind and nearly hairless but grow quickly, reaching adult size in forty to fifty days.

Pikas have a keen sense of sight and hearing, which helps them detect predators, such as weasels, hawks, eagles, and owls. When a pika feels threatened, it issues a loud, shrill, alarm bark and nearby pikas immediately hide in their burrows or in rock crevices. The one exception is when a weasel is detected, the pika remains silent, since the small weasel can follow pikas into their hiding places. Pikas live an average of one to two years and more rarely, four to six years in the wild.

VICTIM OF GLOBAL WARMING

Many scientists believe the American pika will become the first mammal to become extinct due to the effects of global warming. The American pika lives in the high mountains of the western United States and Canada but as the climate gets warmer, the mammals are forced to move to higher elevations to find suitable habitats. A study between 1994 and 1999 in the Great Basin, eastern Sierra Nevada, and western Rocky Mountains found a 30 percent drop in the population of American pikas. Scientists believe the decline of the American pika should be a wake-up call about the consequences of global warming, which many blame on human pollution of the atmosphere.

PIKAS AND PEOPLE

Pikas have little economic importance to humans. They are too small to be used as food, although they are sometimes hunted for their fur, particularly in China. Pikas are sometimes considered agricultural pests and killed by farmers.

CONSERVATION STATUS

Four species of pika are listed by the World Conservation Union (IUCN) as Critically Endangered, facing an extremely high risk of extinction, dying out, in the wild; four species are listed as Endangered, facing a very high risk of extinction; and ten species are listed as Vulnerable, facing a high risk of extinction. One species, the Sardinian pika is considered Extinct.

AMERICAN PIKA (Ochotona princeps): SPECIES ACCOUNTS

Physical characteristics: The American pika is a medium-sized pika with short ears, an oval body shape, and no apparent tail. American pikas have a body length of 6 to 8.5 inches (16.2 to 21.6 centimeters) and weigh about 6 ounces (168 grams). Their hind feet are relatively large compared to their body, 1 to 1.4 inches (2.5 to 3.5 centimeters).

Geographic range: The American pika is found in the western United States in Oregon, Washington, Idaho, Montana, Wyoming, Colorado, Nevada, California, and New Mexico, and in British Columbia in western Canada.

Habitat: American pikas are found in rocky mountain areas, grassland, coniferous forest, deciduous forest, and the border between meadows and rocky terrain.

Diet: American pikas are herbivores, meaning they eat mainly plants. Their diet includes grasses, thistles, sedges (a wetland plant that resembles grass), and fireweed. Because pikas live in climates with harsh winters, most species build large hay piles during the summer to provide food during the winter. They cut off grass stems at the root and bring them to selected places on the surface, piling them into conical-shaped mounds. Once dry, each hay pile can weigh from 2 to 5 pounds (0.9 to 2.25 kilograms). Some pikas store their hay in tree hollows, under tree stumps, and in rock cavities. Each of these stashes can weigh from 15 to 40 pounds (6.75 to 18 kilograms).

Behavior and reproduction: American pikas are diurnal, meaning they are most active during the day. They are territorial, meaning they defend an area they consider their home from intruders. Males and females have separate territories. They spend most of their day looking for food, guarding their territory, and sunning themselves on rocks.

American pikas usually breed from late April to early July. The female gives birth to two to four babies in the spring or summer. The gestation period is about thirty days.

American pikas and people: American pikas play an important role in maintaining the diversity and abundance of alpine meadow plants through their storage of grasses for food during the winter.

Conservation status: The American pika is not listed as threatened by the IUCN. However, populations have drastically declined between 1994 and 1999 and continued to decline into 2004. Seven subspecies (populations of a species living in specific areas) are listed by the IUCN as Vulnerable and several subspecies are considered threatened or endangered by other conservation groups. ∎

NORTHERN PIKA (Ochotona hyperborea): SPECIES ACCOUNTS

Physical characteristics: The northern pika, also known as the Siberian pika, is slightly larger than the American pika. It has a body length of 7 to 12 inches (17.5 to 30.0 centimeters) and weighs about 7 ounces (200 grams). Northern pikas have medium brown fur on their upper bodies and orange to cream fur on their undersides.

Geographic range: The northern pika has the largest distribution range of any pika species. It ranges from eastern Siberia to Sakhalin Island in the Sea of Okhotsk and the northernmost Japanese island of Hokkaido. It is found in eastern Russia, Japan, Mongolia, North Korea, and Manchuria in northern China.

Habitat: Northern pikas live in high grassy plains, coniferous forest, tundra, among rocky outcroppings and crevices, and in burrows under large stones on the land surface.

Diet: Northern pikas are herbivores, meaning they eat mainly plants. Their diet consists mostly of grasses and herbs. Like other


pikas, they build hay piles of grasses that they feed on during the harsh winters.

Behavior and reproduction: Northern pikas are generally very social and curious. They are believed to be monogamous (muh-NAH-guh-mus), meaning a male and female pair for life. The pairs usually live in small colonies. Most females have two litters of babies during the summer, with each litter consisting of one to five babies.

Northern pikas do not survive in captivity. The subspecies Manehurian (Manchurian) pika dies within an hour after being caught by humans.

Northern pikas and people: Northern pikas have little economic importance to humans.

Conservation status: Northern pikas are not listed as threatened by the IUCN. However, the subspecies Ochotona hyperborea yesoensis found on Hokkaido Island is considered endangered by the Japanese government. ∎

FOR MORE INFORMATION

Books:

Macdonald, David. The New Encyclopedia of Mammals. Oxford, U.K.: Oxford University Press, 2001.

Miller, Sara Swan. Rabbits, Pikas, and Hares. New York: Franklin Watts, Inc., 2002.

Nowak, Ronald M. Walker's Mammals of the World, 6th ed. Baltimore: Johns Hopkins University Press, 1999.

Periodicals:

Brown, Paul. "American Pika Doomed as First Mammal Victim of Climate Change."The Guardian (August 21, 2003).

Buck, Kelly L., and Brandon Sheafor. "Selection of Phenolics in Alpine Plans by Ochotona princepes (North American Pikas)." The Ohio Journal of Science (March 2003): A-11.

Smith, Andrew T., and Marla L. Weston. "Ochotona princeps." Mammalian Species (April 26, 1990): 1–8.

Sohn, Emily. "Now Mammals are Feeling the Heat." New Scientist (October 5, 2002): 9.

Web sites:

Myers, Phil, and Anna Bess Sorin. "Family Ochotonidae (Pikas)." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Ochotonidae.html (accessed on July 7, 2004).

Jansa, Sharon. "Ochotona princeps (American Pika)." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Ochotona_princeps.html (accessed on July 7, 2004).