Ochotona princeps

The American pika is a small rodent-like relative to rabbits that has a round body, large, round ears, and is between six and eight inches long. Generally weighing about six ounces, the pika is diurnal, meaning it is active during the day.

Mating first occurs before the snow starts to melt. Females give birth to 2 to 4 offspring, which are weaned in 3 to 4 weeks. After about one month, the offspring leave the mother and grow to adult size after an additional two months. The females may mate again, and may have more than one litter. Pikas eat a variety of plants, including grasses, thistles, sedges, and flowers. The pika is active all year, and stockpiles dried vegetation deep down between rocks for the winter.

They live in between rocks on high elevation boulder and talus slopes, and are very sensitive to high temperatures.

The habitat range of the pika extends from British Columbia and Alberta in Canada, down through the Rocky Mountains to New Mexico. They are also found in the Sierra Nevada Range.

There is concern that some pika populations may be adversely affected by warming temperatures due to global climate change, which decreases the amount of suitable high elevation habitat. However, the pika is not listed as endangered or threatened as of February, 2010. A U.S. Fish and Wildlife report indicates that some pika populations may be able to adapt to higher temperatures.

"American Pikas scent-mark with their cheek glands, and also communicate with both long and short vocalizations. Short calls are uttered as alarms and to announce that they are departing or returning from foraging, and males perform a ""song"" during the breeding season. Males and females maintain individual, same-size territories, usually living next to an individual of the opposite sex. Pikas seem to spend much of the day sitting still, observing their surroundings. Females breed when they are a year old, and have a litter of three after a 30-day gestation period. The young are independent about a month after birth. Predators include coyotes, long-tailed weasels, martens, and ermine."

Adaptation: The shapes of the molar crowns of lagomorphs, such as this American pika, Ochotona princeps, and the Antelope Jackrabbit, Lepus alleni, are fairly simple on the surface but they are also un-rooted, and consequently, ever-growing, an adaptation for an extremely abrasive diet.

Links:
Mammal Species of the World
Click here for The American Society of Mammalogists species account

The American Pika has a widespread, but discontinuous geographic distribution throughout mountainous areas of western United States and southwestern Canada (British Columbia and Alberta) (Smith and Weston 1990, Hafner and Smith 2010). The accompanying range map demarcates the five recognized subspecies (Hafner and Smith 2010).

There is paleontological evidence that supports a past distribution that once included now-uninhabited, low-lying regions of the Great Basin and other parts of North America (Mead 1987, Hafner 1993, Grayson 2005). Following Brown's (1971, 1978) suggested mechanism of Holocene extinctions after a period of colonization during the Pleistocene, Grayson (1987, 2005) and Mead (1987) concluded that the American Pika became extinct from low-lying regions in the Great Basin between 7,500 and 5,000 B.P. The current discontinuous distribution; however, is not supported by a colonization-driven system (Brown 1971, 1978; Beever et al. 2003; Smith 1974a). Elevational distribution varies with latitude. Pikas may live from close to sea level (for example, the Columbia River Gorge, Oregon; Simpson 2009) to 3,000 m in the northern extent of their range (Smith and Weston 1990). In the southern-most portions of their range they only occasionally extend below 2,500 m and are known to occupy sites as high as 3,887 m in the White Mountains, California, and 3,786 in the Sierra Nevada, California (Smith and Weston 1990, Millar and Westfall 2010). Pikas have been reported to occur as high as 4,146 m on Wheeler Peak, New Mexico (Howell 1924) and 4,175 m on Mt. Evans and Pike’s Peak, Colorado (Markham and Whicker 1973, Erb pers. comm.). There are numerous locations where pikas persist in what would appear to be climatically marginal sites, such as: Lava Beds National Monument, California; Craters of the Moon National Monument, Idaho; the Columbia River Gorge, Oregon (where they are found as low as 30 m in elevation); the western Cascade Range, Oregon; and select localities throughout the Great Basin (Howell 1924, Horsfall 1925, Anthony 1928, Beever 2002, Beever et al. 2008, Simpson 2009, Millar and Westfall 2010, Rodhouse et al. 2010, Manning and Hagar 2011). Persistence of American Pikas in these localities appears to reflect a strong decoupling of microclimates used by pikas (which are notably temperature sensitive; see Habitats and Ecology, below) from the macroclimate of the region.

In contrast to recent findings of pikas at atypical low-elevation areas, other studies have documented extirpations of pikas on a number of historically occupied low-elevation sites throughout the Great Basin. Surveys conducted from 1994-1999 in the Great Basin found that six of 25 historical American Pika localities (records of occurrence documented from 1898–1956) appeared to be extirpated (Beever et al. 2003). Follow-up surveys conducted from 2003-2008 documented three additional extirpations and one site that appeared functionally extirpated (Beever et al. 2010, 2011). This rapid and accelerating rate of extirpation has been accompanied by an upslope movement of the low-elevation range boundary of pikas on extant sites in the Great Basin, and taken together these shifts appear to be driven by contemporary climate change (Beever et al. 2010, 2011; Wilkening et al. 2011). Recent surveys of historical sites in regions other than the Great Basin have also noted some extirpations, albeit at a smaller proportion of sites. For example, Erb et al. (in press) sampled 69 historical sites in the southern Rocky Mountains from New Mexico to Wyoming, including the lowest elevation sites within regions, and documented four extirpations (and two of these sites were subsequently recolonized (Erb pers. comm.). The Grinnell resurvey in Yosemite National Park, California, found a single extirpation of a pika population along a transect from the eastern to the western extent of the Sierra Nevada (Moritz et al. 2008). Numerous inventories and surveys are currently underway to document the extent of the species’ distribution across the geographic range of the American Pika and the status and trend of pika populations with regard to factors associated with contemporary climate change.

American pikas can be found throughout the mountainous regions of western North America. Their geographic range extends as far south as New Mexico and California, as far north as British Columbia, and as far east as Colorado.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Distributed discontinuously in mountainous areas in western North America, from central British Columbia and southern Alberta south to east-central California, Nevada, southern Utah, and northern New Mexico; east to Wyoming and Colorado; ranges from sea level to 3000 m in north, uncommon below 2500 m at southern range limit (Smith and Weston 1990; Hoffmann, in Wilson and Reeder 1993). See detailed map in Hafner and Sullivan (1995).

Ochotona princeps is intermediate in size when compared to other ochotonids. Its body mass exhibits a great deal of variation and ranges from 121 to 176 grams. In certain parts of its range, males are larger than females, but only slightly (Smith and Weston, 1990). The body of O. princeps is ovoid, with short ears, long vibrissae (40-77 mm), short limbs, and no visible tail. Its hind paws are digitigrade, have four toes (compared to five on the front), and range from 25 to 35 mm in length. Both sexes have a pseudocloacal openings, which must be everted to expose the penis or clitoris. Females have six mammae which do not enlarge during lactation. Ochotona princeps has a high body temperature (average of 40.1°C) and relatively low upper lethal temperature (average of 43.1°C). It has a high metabolic rate (1.53 cm^3 oxygen/hour), and thermoregulation is behavioral rather than physiological.

Pelage color of American pikas changes seasonally but maintains an off-white hue on its ventral surface (as opposed to white in Ochotona collaris). On its dorsal surface, pelage ranges from grayish to cinnamon-brown in the summer. In the winter, their dorsal pelage is gray and is twice as long as summer pelage. Their ears are round, covered with dark hair on their internal and external surfaces, and edged in white. Their paws are densely furred, including the soles, with the exception of small black naked pads at the ends of the toes (Smith and Weston 1990). Their skull is slightly round with a flat, broad interorbital region. Other distinguishing characteristics of the American pika's skull include a slender rostrum, nasals that are widest anteriorly, maxillae with one large fenestration (rather than numerous small fenestrae of Leporidae), an elongated jugal, which forms a prominent projection from the posterior zygomatic arch, and a dental formula of 2/1, 0/0, 3/2, 2/3 totaling 26 teeth.

Range mass: 121 to 176 g.

Range length: 162 to 216 mm.

Average basal metabolic rate: 1.53 cm^3 oxygen/hour.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike; male larger

Average basal metabolic rate: 0.932 W.

Length: 22 cm

Weight: 128 grams

Sexual Dimorphism: None

Length:
Range: 162-216 mm

Weight:
Range: 121-176 g

Habitat and Ecology

Systems

• Terrestrial

American pikas inhabit areas of broken rock and talus fields fringed by alpine meadows. They are most common in cool, moist habitats above tree line. In the northern part of their range, they can be found from sea level to 3,000 meters; however, in the southern part of their range, American pikas are rarely found below 2,500 meters (Chapman and Flux, 1991).

Range elevation: sea level to 3000 m.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: tundra ; taiga ; mountains

Comments: Restricted to rocky talus slopes, primarily the talus-meadow interface. Often above treeline up to limit of vegetation. Also found at lower elevations in rocky areas within forests or near lakes. Occasionally on mine tailings, or piles of lumber or scrap metal. Does not dig burrows but may enlarge den or nest site under rock.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

American pikas are generalized herbivores that select forage by assessing its nutritional value. Preferred plants have higher protein, lipid, and water content and higher caloric value than non-preferred plants (Chapman and Flux, 1991). Although certain plant species are avoided due to the presence of toxins, these plants may be cached in haypiles for winter consumption. Some toxins act as natural preservatives that wear off by the time the plant is consumed. Caching, also known as haying, occurs during summer. Haypiles generally consist of forbs and tall grasses, but up to 30 species of plants may be found in a single haypile. Most haypiles are constructed near the talus-meadow interface and serve as territory markers. When winter arrives, haypiles are moved into burrows and used as their main food supply. During winter, American pikas may also feed upon cushion plants and lichens in the subnivean zone to supplement their diet. In the summer, American pikas typically eat short alpine grasses. Forbs and shrubs constitute 78 to 87% of their diet, with alpine avens, clovers, and sedges making up the remaining 22 to 13% of their diet (Fitzgerald, Meaney, and Armstrong, 1994). Occasionally, conifer needles and bark are also eaten. They are not obligate drinkers as water is primarily obtained via ingested plants.

American pikas create two types of fecal droppings: a hard brown round pellet and a soft shiny string of material (the caecal pellet). Pikas consume the caecal pellet (which has high energy value and protein content) or store it for later consumption. Only about 68% of the ingested food is assimilated, making the caecal pellets an important part of the American pika's diet.

Plant Foods: leaves; wood, bark, or stems; flowers

Other Foods: dung

Foraging Behavior: stores or caches food

Primary Diet: herbivore (Folivore , Lignivore); coprophage

Comments: Feeds primarily on grasses and sedges; also eats some flowering plants and shoots of woody vegetation. In late summer and fall, harvests and stores food (forbs, grasses, marmot pellets) for winter consumption; stored food may be most important when winter is unusually harsh or long (see Smith and Weston 1990). May forage in winter in snow tunnels. Ingests caecal pellets, either directly or after storage.

American pikas are considered allogenic engineers (i.e., altering the environment through their activities). Their large haypiles, containing both plant and fecal matter, are not entirely consumed during the winter, leaving large accumulations of decomposing biomass to act as fertilizer and a potential food source for other animals. As fertilizer, haypiles ultimately increase soil nitrogen, a limiting resource for vegetation at high altitude.  Also, American pikas are host to many species of intestinal parasites (Coccidia) and parasitic fleas (Siphonaptera).

Ecosystem Impact: keystone species

Commensal/Parasitic Species:

• Eimeria cryptobarretti
• Eimeria banffensis
• Eimeria calentinei
• Eimeria klondikensis
• Isospora marquardti
• Eimeria barretti
• Eimeria princeps
• Eimeria worleyi
• fleas (Siphonaptera)

American pikas are moderately camouflaged and when a potential predator is detected, they emit an alarm-call informing the rest of the community of its presence. Alarm calls are emitted less frequently for small predators, as small predators may be able to chase them into the talus interstices. Small predators consist of long-tailed weasels (Mustela frenata) and ermines (Mustela erminea). Large predators, such as coyotes (Canis latrans) and American martens (Martes americana), are especially adept at capturing juveniles who are not quick enough to escape. Golden eagles (Aquila chrysaetos) also feed on American pikas, but their impact is minimal.

Known Predators:

• coyote (Canis latrans)
• long-tailed weasel (Mustela frenata)
• ermine (Mustela erminea)
• American marten (Martes americana)
• golden eagle (Aquila chrysaetos)
• bobcat (Lynx rufus)
• red fox (Vulpes vulpes)
• northern goshawk (Accipiter gentilis)
• red-tailed hawk (Buteo jamaicensis)
• marsh hawk (Circus cyaneus)
• prairie falcon (Falco mexicanus)
• common raven (Corvus corax)

Anti-predator Adaptations: cryptic

Home range size varies seasonally, largest during spring breeding season; defends haypiles in late summer. May defend territory; home range size about twice as large. Male and female territories average same size. Reported home ranges: 0.3-0.5 ha (Barash 1973); and mean 0.26 ha, range 0.04-0.30 ha (Kawamichi 1976). Adjacent home ranges tend to be occupied by opposite sexes. Population density was 3-10 per ha in favorable habitat in Colorado in mid-August (same as in other regions); population relatively stable due to density-related social behavior (Southwick et al. 1986). Juveniles tend to stay on natal home range or an adjacent one. Adult mortality 37-56% per year.

American pikas communicate via vocalizations and scent marking, and they can discriminate between individuals through calls and cheek-gland secretions. They make 2 characteristic vocalizations, short calls and long calls. Short calls are used as an alarm when predators are present or as a warning signal to potential intruders (i.e., to defend one's territory). Alarm calls are usually repetitive short calls that change in frequency depending on the type of predator seen (e.g., large vs. small). Long calls are almost exclusively given by adult males and are most common during breeding season, owever, both males and females may sing in the autumn. Short call duets are also sung by mating pairs in an effort to maintain social tolerance.

American pikas use urine, feces, and cheek marks while scent marking. Cheek markings, produced from apocrine sweat glands, are used to attract potential mates and to demarcate territories. They are spread by both sexes by rubbing their jowls on rocks. During breeding season or upon colonization of a new territory, cheek marking occurs with elevated frequency. Urine and feces are usually placed by haypiles to mark ownership.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: duets ; scent marks

Perception Channels: visual ; acoustic

Comments: Active throughout the year. Relatively inactive on warm days; near lower elevational limit may be inactive at midday in hot weather (Smith and Weston 1990).

Average annual mortality of American pikas is 37 to 53%, and age-specific mortality is highest for 0 to 1-year-olds and 5 to 7-year-olds. The maximum age of American pikas in the wild and in captivity is 7 years, with an average life expectancy of 3 years in the wild.

Range lifespan
Status: wild: 7 (high) years.

Range lifespan
Status: captivity: 7 (high) years.

Average lifespan
Status: wild: 3 years.

Average lifespan
Status: wild: 6.0 years.

Average lifespan
Status: wild: 7.0 years.

Maximum longevity: 7 years (captivity) Observations: It has been estimated that these animals live up to 7 years in the wild (David Macdonald 1985). One wild born captive specimen was about 7 years old when it died in captivity (Richard Weigl 2005).

American pikas are monogamous, and mate pairs are formed with adults from adjacent territories. When more than one potential mate is available, females may exhibit mate choice (Smith and Weston, 1990).

Mating System: monogamous

American pikas typically mate as yearlings. Males are considered sexually active when their testes are 11 mm in length or greater (Smith and Weston, 1990). American pikas are reflex ovulators (i.e., ovulation only occurs after breeding) and are seasonally polyestrus. Each female has 2 litters per year, with an average of 3 young per litter. Breeding commences 1 month before snow-melt and gestation last approximately 30 days. At low elevations, parturition occurs as early as March but occurs from April to June at higher elevations. Pups weigh between 10 and 12 g at birth and are weaned by 28 days old. Lactation significantly reduces a female's fat reserves, and although females exhibit postpartum estrus, they only nurse the second litter if the first does not survive.

Breeding interval: American pikas breed twice yearly, during the same breeding season.

Breeding season: American pikas breed one month before snow-melt and once again following the birth of their first litter (postpartum estrus)

Range number of offspring: 1 to 6.

Average number of offspring: 3.

Average gestation period: 30 days.

Range birth mass: 10 to 12 g.

Range weaning age: 18 to 35 days.

Average weaning age: 28 days.

Average time to independence: 4 weeks.

Average age at sexual or reproductive maturity (female): 347 days.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); induced ovulation ; fertilization ; viviparous ; post-partum estrous

Average gestation period: 30 days.

Average number of offspring: 3.

Average age at sexual or reproductive maturity (female)
Sex: female: 347 days.

American pikas are born slightly altrical; they are blind, slightly haired, have fully erupted teeth, and weigh between 10 and 12 grams at birth. For the first 18 days, young are completely dependent on their mothers. Pups open their eyes at 9 days of age. Mothers spend most of their time foraging, but visit the nest once every 2 hours to nurse for an average of 10 minutes. Pups become independent by about 4 weeks old (soon after weening). American pikas exhibit a remarkable growth rates compared to other members of Lagomorpha, and can reach adult size after only 3 months (Smith and Weston, 1990).

Parental Investment: altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)

Seasonally polyestrus. Gestation lasts approximately 30 days. Produces 1 or 2 litters of usually 2-5 young/litter (average often 3 at high elevations), between May and September; most young come from first litters. In most areas parturition begins in May with a peak in June, occurs as early as March in some low elevation areas (Smith and Weston 1990). In Colorado, initiates 2 litters annually but only one is weaned; births late June-early August. Young dependent on mother for at least 18 days, weaned as early as 3-4 weeks. Juveniles establish territories and haypiles in summer of birth, but do not breed until their 2nd summer. Maximum lifespan 7 years.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 2 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 1996
  Lower Risk/least concern
  (Baillie and Groombridge 1996)

Due to its abundance and widespread distribution, the IUCN lists Ochotona princeps as a species of least concern. However, of the thirty six recognized subspecies, seven are listed as vulnerable and one, O. p. schisticeps, is listed as near threatened. The seven vulnerable subspecies (O. p. goldmani, O. p. lasalensis, O. p. nevadensis, O. p. nigrescens, O. p. obscura, O. p. sheltoni, and O. p. tutelata) are all found in the Great Basin and are currently experiencing major threats that have resulted in local extirpations. The greatest threat to American pikas, especially those in the Great Basin, is likely global climate change as they are extremely sensitive to high temperatures. American pikas can die within an hour if ambient temperatures rise above 23°C (75°F). Many populations are expected to migrate north or move to higher elevations. Unfortunately, American pikas are very poor dispersers.

Various organizations have suggested placing Ochotona princeps under the protection of the endangered species act. Potential solutions to local population declines may include legislation changes to decrease the amount of global warming stressors, increasing awareness, identification of new protected areas, and re-introductions in areas where O. princeps has been extirpated.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Seven subspecies are Vulnerable: O. princeps goldmani, O. princeps lasalensis, O. princeps nevadensis, O. princeps nigrescens, O. princeps obscura, O. princeps sheltoni, and O. princeps tutelata

Population

Population Trend

Major Threats

Conservation Actions

There are no known adverse effects of Ochotona princeps on humans.

There are no known positive effects of Ochotona princeps on humans.