PIKAS

Pika (genus Ochotona) are small short-legged and virtually tailless egg-shaped mammal found in the mountains of western North America and much of Asia. According to Encyclopædia Britannica: “Despite their small size, body shape, and round ears, pikas are not rodents but the smallest representatives of the lagomorphs, a group otherwise represented only by hares and rabbits (family Leporidae). The 29 species of pika are remarkably uniform in body proportions and stance. Their fur is long and soft and is generally grayish-brown in colour, although a few species are rusty red. Unlike those of rabbits and hares, the hind limbs are not appreciably longer than the forelimbs.

According to Animal Diversity Web: The family Ochotonidae comprises the pikas, including one extant genus Ochotona and 30 currently recognized species (Hoffman and Smith, 2005). There are more than 30 extinct genera that have been identified as far back as the Eocene, one of which, Prolagus, went extinct in the late 18th century. Today, Ochotonidae represents approximately 1/3 of lagomorph diversity. Their range is primarily in Asia although there are two North American species. The main differences from leporids are their 1) small size, 2) small, rounded ears, 3) concealed tails, 4) lack of supraorbital processes, and 5) 2, rather than 3, upper molars (Smith, 2008). [Source: Aspen Reese, Eric Sargis, Yale University, Animal Diversity Web, University of Michigan, animaldiversity.org ]

“There are two main ecotypes, one of which is associated with rocky habitats and the other with meadow, steppe, forest, and shrub habitats. Each ecotype is associated with specific life history traits as well as behavior. Most species fall within one of these ecotypes, although there are some species which exhibit intermediate characteristics. The average mortality of talus-dwelling species is low and many are long lived compared to most small mammals. Meadow-dwelling species experience high annual mortality and few individuals live more than two years. ~

Pika Range and Habitat

According to Animal Diversity Web: “Although the historic range of ochotonids included Asia, Europe, northern Africa, and North America, today ochotonids are found only in Asia and the high mountains of western North America. Their center of diversity is China, where 24 species are found (Smith, 2008). In Asia, pikas are found as far west as Iran, south into India and Myanmar, and into northern Russia. [Source: Aspen Reese, Eric Sargis, Yale University, Animal Diversity Web, University of Michigan, animaldiversity.org ~]

Ochotonids are found in two distinct habitats: talus habitat or in meadow, steppe, forest, and shrub habitats. Talus-dwellers inhabit the crevices between rocks on mountain slopes. These species forage in the alpine meadows that abut the rocks or from the vegetation that grows between the rocks. They are found across a wide altitudinal gradient from below 90 to above 600 meters. Species that are typically found in talus habitats are alpine pikas, silver pikas, collared pikas, Chinese red pikas, Glover’s pikas, Himalayan pikas, northern pikas, Ili pikas, large-eared pikas, American pikas, Royle’s pikas, and Turkestan red pikas. ~

“Non-talus dwelling pikas are found in a variety of vegetated habitats where they forage and produce burrows. The meadows they occupy are also typically at high elevation. The meadow-burrowing pikas are all found in Asia and include Gansu pikas, black-lipped pikas, Daurian pikas, Kozlov’s pikas, Ladak pikas, Muli pikas, Nubra pikas, steppe pikas, Moupin pikas, and Thomas’s pikas. ~

“Some species, including Pallas's pikas and Afghan pikas are known to occur in both habitat types and are referred to as intermediate species. Although intermediate in habitat, these species exhibit the life-history traits and behavior of meadow-dwelling pikas. ~

Pika Characteristics

According to Animal Diversity Web: Ochotonids exhibit little physical variation. They are generally small, ranging in body length from 125 to 300 milimters and weighing 70 to 300 grams. Unlike leporids, pikas lack a visible tail and have short rounded ears with large, valvular flaps and openings at the level of the skull. The ears are only weakly movable and their nostrils can be completely closed. They have short limbs with the hind limbs barely longer than the forelimbs. They have 5 front digits and 4 hind digits all with curved claws. The soles of the feet are covered by long hair but the distal pads are exposed. They are digitigrade while running but plantigrade during slow movement. Ochotonids have 22 thoracolumbar vertebrae and lack a pubic symphysis. [Source: Aspen Reese, Eric Sargis, Yale University, Animal Diversity Web, University of Michigan ~]

“The skull is generally similar to that of leporids. It is flattened, exhibits fenestration, and is constricted between the orbits. The ochotonid tooth formula is 2/1 0/0 3/2 2/3=26. The first incisors are ever-growing and completely enameled, while the second are small, peg-like, and directly behind the first. The cutting edge of the first incisor is v-shaped. They have a long post-incisor diastema and hypsodont, rootless cheek teeth. Occlusion is limited to one side at a time, with associated large masseter and pterygoideus muscles allowing for transverse movement while the cheekteeth have transverse ridges and basins. The zygomatic arch is slender and not vertically expanded. The jugal is long and projects more than halfway from the zygomatic root of the squamosal to the external auditory meatus. Unlike leporids, pikas lack a supraorbital process. Their rostrum is short and narrow and the maxilla has a single large fenestra. The auditory bulla, which is fused with the petrosal, are spongiose and porous. The bony auditory meatus is laterally directed and not strongly tubular. ~

“Pikas exhibit no sexual dimorphism. Males lack a scrotum and both sexes have a cloaca, which opens on a mobile apex supported by a rod of tail vertebrae. Females have between 4 and 6 mammae, with one pair inguinal and one to two pairs pectoral. Ochotonid coats consist of long, dense, fine fur and are usually grayish brown, although they vary inter- and intra-specifically depending on habitat. Some ochotonids go through two molts, with darker fur during the summer and grayer pelage in the winter. Physiologically, pikas have a high metabolic rate. They also have low thermal conductance and, even at moderately high temperatures, low ability to dissipate heat. ~

Pika Reproduction

According to Animal Diversity Web: Most talus-dwelling pika species are monogamous or polygynous. There are some notable exceptions, including documented cases of polygynandry in collared pikas. In contrast, meadow-dwelling pikas exhibit monogamous, polygynous, polyandrous, or polygynandrous mating systems, depending on the sex ratio at the beginning of the breeding season. [Source: Aspen Reese, Eric Sargis, Yale University, Animal Diversity Web, University of Michigan ~]

“The talus-dwelling species, such as American pikas, exhibit low annual production of offspring. Typically, talus-dwelling pikas produce only one successfully weaned litter of 1 to 5 young a year. On average, approximately 2 young per mother are successfully weaned per year . Juveniles reach sexual maturity as yearlings. Some talus-dwelling species exhibit absentee maternal care typical of lagomorphs. The gestation period of American pikas, for example, is 30.5 days and their breeding season lasts between late April and the end of July. In contrast, meadow-dwelling species have much higher potential reproductive output, but it varies depending on environmental conditions. They can produce litters that are twice as large as those of talus-dwellers up to every three weeks during the reproductive season. The reproductive season of O. curzoniae, a meadow-dwelling species, generally lasts from March to late August but can vary between years and sites. On average, multiple litters are produced each year and most young are successfully weaned. Further increasing their reproductive output, juveniles born early in the breeding season will reach sexual maturity and breed during the summer of their birth. ~

“Some talus-dwelling species exhibit absentee maternal care typical of lagomorphs. Males and females of some meadow-dwelling species participate in affiliative behavior with juveniles as well as mate guarding and defending territories (e.g. Smith and Gao, 1991). Juveniles of meadow-dwelling species also continue to live on the parental territory through at least their first year. ~

Pika Behavior

According to Animal Diversity Web: North American talus-dwelling pikas occupy and defend territories individually, particularly against members of the same sex. Except for when they come together to mate, these talus-dwelling pikas are relatively asocial. Dominance does not extend beyond an individual’s territory. Most social interactions are aggressive and chases and fights result from conspecific intrusion, and the theft of vegetation from the haypiles of conspecifics. Talus-dwelling ochotonids use vocalizations and scent-marking to demarcate their territories, which are relatively large and make up about ½ of their home range. Territories are usually established near the edge of the talus/vegetation border and vary in size depending on species and the productivity of the adjoining vegetation. They are typically between 450 and 525 square meters. [Source: Aspen Reese, Eric Sargis, Yale University, Animal Diversity Web, University of Michigan,~]

“Some Asian talus-dwelling pika species defend territories as pairs. The pair uses the same main shelter and spend most of their time in the same area. They cooperate in hay-storage and communicate using vocalizations, but are asocial outside of the pair. Primarily the males demarcate the territory and defend it against intruders. These territories are typically larger than those of individual pikas, around 900 square meters per pair, and these pikas live at much higher densities.

“In contrast, the Asian meadow-dwelling species are considered to exhibit highly social family groups, consisting of adults as well as young of the year in communal burrows. These species live at much higher densities (more than 300/ha) than the talus-dwelling species and experience more variation in population density over seasons and between years. Meadow-dwelling pika exhibit both affiliative behaviors, such as allogrooming, nose rubbing, and various forms of contact, within family groups, as well as aggressive territorial behaviors toward non-family members. In addition, family members communicate with vocalizations, which can elicit affiliative contact . They also defend territories as a family unit and share communal hay piles. Their territories are also demarcated by scent-marking and vocalizations. ~

“Both ecotypes are poor dispersers and typically do not range far from their natal territory. In talus-dwellers, an individual with control of a territory typically maintains it for life, and upon it’s death will be replaced by a juvenile born in a nearby territory and usually of the same sex. In meadow-dwellers, juveniles will stay in their home burrow for the first year and then less than half will disperse to nearby territories. Males are more likely to disperse, but even then typically move only a few territories away. ~

“Pikas do not hibernate during the winter, but instead stay active in their burrows or rocky crevices. During this time they consume the food caches that they collected during the summer . Ochotonids are primarily diurnal, but can be active at all times of day as well as throughout the year. They are frequently observed sunning themselves on rocks during warmer months. ~

“Most pika species vocalize both for predator alarms and territory defense. They produce a high-pitched 'eek' or 'kie' that is ventriloquial in character. They have also been demonstrated to eavesdrop on the alarm calls of heterospecifics, such as marmots and ground squirrels. Ochotonids can also communicate danger by drumming on the ground with their hind feet. Meadow-dwelling, burrowing species produce multiple types of vocalizations, many of which are used in socializing with conspecifics . Low chattering and mewing noises have also been reported. Both ecotypes also use scent-marking. ~

Lagomorpha Feeding

Lagomorpha— hares, lagomorphas and pikas—have two pairs of sharp, chisel-like incisors (rodents have only one pair) that grow continuously. These are used to chop off grasses and other vegetation with a distinctive, clean, angled stroke.

Lagomorphs are completely vegetarian, and have evolved a unique system for extracting the maximum nutritional value from coarse plants. The food is first passed through their digestive system and discharged as soft feces. Pikas, lagomorphas and hares eat these, These are then reingested and passed through again, emerging as the dry round pellets that you see in clusters all over their feeding grounds.

The way lagomorpha digest leaves thus involves eating their own droppings., When they are asleep in their burrows at night they excrete black sticky pellets from their anus. These are consumed to go through a second round of digestive processing. The second round are excreted outside the den after the lagomorpha wakes up.

Lagomorpha food such as grass and leafy weeds is high in cellulose and difficult to digest. Chewed plant material collect in an area of the digestive tract called the cecum, The cecum contains bacterial colonies that partly break the cellulose down. When the soft feces are ingested they are eaten whole and digested in a special part of the stomach, If they only ate their food once they wouldn’t absorb enough nutrients.

Lagomorphas often feed at night—which is why most people with pet lagomorphas have never seen them eat their poop—and stay in their nests during the day. They lagomorphas have strong chisel-like front teeth and are gnawing animals like rats, mice and squirrels. They have sensitive hearing and smell.

Pika Eating Habits and Predation

According to Animal Diversity Web: Pikas are generalist herbivores and typically collect caches of vegetation, which they live off of during the winter. They consume leaves and stems of forbs and shrubs as well as seeds and leaves of grasses; sometimes they also consume small amounts of animal matter. Like most leporids, they produce two types of feces: soft caecotroph and hard pellets . During the summer, after the breeding season, pikas accumulate large stores of many different plants in their haypiles, which they then store for winter consumption. Their foraging patterns varies throughout the season in accordance with which plants are available, preferred, and/or have the highest nutritional content, selecting for higher caloric, lipid, water, and protein content. The foraging habits of pikas affect plant communities. Pikas alter which plants are collected while foraging as well as how far they go to forage, depending on whether they are being immediately consumed or are being added to a haypile. This variation results in a mosaic of plant community composition. This selective foraging has been demonstrated to stabilize plant community composition and slow the process of succession, as well as reduce the number of seeds in the soil. [Source: Aspen Reese, Eric Sargis, Yale University, Animal Diversity Web, University of Michigan ~]

“Pikas serve as an important food source to both birds and mammals in all of the habitats they occupy. Meadow-dwelling pikas, in particular, can be a preferred food or buffer species throughout the year, but are especially important prey in the winter as they are still active while similarly sized rodents hibernate . During high-density years, burrowing pikas can be the most important food source for Asian steppe predators, sometimes making up more than 80 percent of a predator’s diet. In addition to being prey for small to medium-sized carnivores, pikas are also often consumed by larger carnivores, including wolves and brown bears. ~

Known Predators include: wolves (Canis lupus), hawks, eagles, and buzzards (Accipitridae), owls (Strigiformes), polecats and weasels (Mustela), brown bears (Ursus arctos), American black bears (Ursus americanus), Asiatic black bears (Ursus thibetanus). ~

Humans and Ecosystem Roles of Pikas

According to Animal Diversity Web: In addition to the important ecosystem roles that ochotonids serve as consumers and as prey, they also alter their environments through bioturbative ecosystem engineering. The burrowing of meadow-dwelling pikas improves soil quality and reduces erosion. The accumulation and decomposition of leftover caches and the feces in burrow systems also helps increase the organic content of soil . In addition to their abiotic benefits, pika burrows are used by other mammals and birds and their caches are often consumed by other herbivores . The haypiles of talus-dwelling pikas also improve soil quality upon decomposition, thereby facilitating plant colonization of the talus. [Source: Aspen Reese, Eric Sargis, Yale University Animal Diversity Web, University of Michigan ~]

“Traditionally, pikas were a valuable source of fur throughout Asia and in particular the Soviet Union . Additionally, some traditional herdsmen selectively graze their livestock in the winter on pika meadows where haypiles are exposed above the snow. ~

“Some ochotonid species are considered pests in Asian countries, where they are believed to compete with livestock for forage, erode soil, and negatively affect agricultural crops such as apple trees and wheat . It has been demonstrated that pikas can harm agricultural crops but no control studies have been conducted that support other claims. Pika foraging has been implicated in accelerating range deterioration but only in areas that were already overgrazed. Millions of hectares have been subject to poisoning in an effort to control pika numbers with mixed results, including extermination of non-target species.

“Today, four ochotonid species (silver pikas, Hoffmann's pikas, Ili pikas, Kozlov's pikas) are classified as endangered or critically endangered due to habitat loss, poisoning, or climate change. Additionally, many subspecies are threatened due to low vagility and its effects on stochastic metapopulation dynamics. Not enough is known about many species (10 percent are still considered data deficient by the IUCN) to truly assess their conservation status. Until the systematics of the family is better understood it will be hard to determine the outlook for many populations. Due to their low tolerance for high temperatures and low vagility, ochotonids are considered especially vulnerable to warming so the need for conservation efforts is expected to increase with climate change.

Large-Eared Pika

According to Animal Diversity Web: “Large eared pikas, Ochotona macrotis, are most frequently found on the Qinghai-Tibet Plateau in Central Asia, as well as in the Tienshan and Pamir mountain ranges. This species of ochotonid is also encountered in the Nepal Himalayas, Punjab, and Kashmir, as well as in remote areas surrounding China's western forests in the Sinkiang Province. [Source: Dana Jordan, Humboldt State University, Animal Diversity Web, University of Michigan ~]

“In general, pikas establish nests among rocky debris on talus slopes formed by glaciers. The rocks serve as both a home and refuge against predators. The size of the rocks is important for pikas because these animals use natural crevices and tunnels to travel from one location to another. Spaces that are too large may permit predators to reach the pikas. ~

“One can often identify the presence of a pika by the presence of droppings. Pellets are usually confined in consistent piles among the talus. Rocks with crusty white urine stains also suggest pika presence. This particular species can occur at elevations as high as 6,100 meters. ~

“To the extent that these animals serve as prey, they have impact in local food webs. In addition, they are likely to influence local plant communities through their foraging behavior. These pikas have no known positive impact on human economies. Although other pikas make hay piles that can be used by domestic animals grazing in the area, this species is not known to make such hay piles. Large-eared pikas have been known to creep in and live among the walls of homes near their territory. In such circumstances, unattended food around the house is often nibbled at or stolen away to the nests. Ochotona macrotis and O. royalei have in the past been classified by taxonomists as the same species. However, modern day genetics suggests that they are separate species. Ochotona macrotis occurs at a higher elevation than its sister group, O. royalei. ~

Large-Eared Pika Characteristics

According to Animal Diversity Web: “Large-eared pikas are similar physically to Ochonta royalei, but with larger ears. These animals are approximately 150 to 200 milimters in length. They can weigh up to 120 grams. This particular ochotonid has the largest pinnae of any member of the family, hence its common name. Like other lagomorphs, ochotonids have an extra pair of insisors behind the first. The pelage is thick, soft, and slightly silky. Unlike rabbits and hares, ochotonids have visible toe pads surrounded by well furred feet. [Source: Dana Jordan, Humboldt State University, Animal Diversity Web, University of Michigan ~]

“Among pikas in general, two molts occur yearly which vary in color, due to seasonal changes. Females often lose their fur later in the season than male ochotonids. It has been suggested that sexual differences in timing of molt is related to reproduction. ~

“Although data for O. macrotis are lacking, it is thought that pikas in general have a lifespan of one to three years. Long-earned pikas are likely to have a similar maximum lifespan. The metabolic rate of ochotonids is high, particularly those species such as O. macrotis, which experience harsh climates and conditions with much snow. ~

Large-Eared Pika Reproduction and Offspring

According to Animal Diversity Web: “These animals appear to mate polygynously. It is not known whether courtship exists among ochotonids. As in other lagomorphs, ovulation is induced by copulation. Suprisingly, aggressiveness among male ochotonids is reduced during the onset of female reproduction. It is not until the young are slightly grown that males become territorial. The most severe period of male agressiveness occurs during the fall, after reproduction has occured. During mid-summer, males become highly territorial and aggressive male-male chases occur once per hour. [Source: Dana Jordan, Humboldt State University, Animal Diversity Web, University of Michigan ~]

“Both male and female large-eared pikas become sexually mature around one year of age. Mating takes place during a short period in the early summer. Gestation lasts only 30 days. Reproductive capacity is low, with a typical litter of two pups. It has been suggested that this phenomenon is linked to the short mating season of O. macrotis. Large-eared pikas mature quickly, with time to weaning lasting only a month. ~

“By one year of age, males stake out new territories and will often tresspass onto those of an adjacent males. Females, on the other hand, usually remain in one area until a mate is chosen. As with most mammals, male pikas do not extend any care to their offspring. Instead, females provide their young with protection, food, and grooming. By one week of age, the newly born pikas begin walking and making vocalizations. ~

Large-Eared Pika Behavior

Like other pikas, large-eared pikas do not hibernate during the winter. Whereas other species are active throughout the day, O. macrotis is the most active around mid-day. The remainder of the day is spent crouching on prominent rocks, sun-bathing, or watching for predators. If the temperature is too high, animals take refuge for extended periods of time beneath the talus. Unlike other pikas, O. macrotis does not perform the typical hay-gathering ritual that often comes to be associated with ochotonids. Hay-gathering involves the cutting and drying of grasses, which are stacked in piles among the rocks for later use as bedding and food. [Source: Dana Jordan, Humboldt State University, Animal Diversity Web, University of Michigan ~]

“Pikas are typically more alert of their surroundings after the snow has melted than at any other time of the year because of their prolonged absence from the outside world. The loss of the snow, which provided temoporary protection, makes the ochotonids more accessible to predators. Behavior also changes through the course of the season, from the time of the breeding season to after the offspring are born. Trespassers are often allowed to cross boundaries during certain times of the year, but not during others. ~

“Ochontids typically use sharp, high-pitched whistles to communicate with each other. Such calls are often used when predators are close at hand. Calls vary in range and pitch for different classes of predators. Vocalizations are also used to advertize territorial boundaries. Barks against invasive males are frequent during the mating months. Like other Asiatic species, large-eared pikas have been known to give nocturnal calls. Suprisingly, neither O. macrotis and O. royalei are as vocal as other pika species. Because thse animals rely less on vocalizations as a means of communication, it has been suggested that O. macrotis uses other methods of communication, such as pheromones. As in all diurnal species, visual communication, including body posture, is probably important between conspecifics. Tactile communication occurs between mates, rivals, and between mothers and their young. ~

Large-Eared Pika Eating Habits and Predation

According to Animal Diversity Web: “In general, pikas eat all available plant vegetation such as grasses, sedges, twigs, and flowers. During the first month after winter, there is a great deal of competition to consume new vegetation. Consumption of grasses and other plant-foods occurs fromt the end of the matter that has been bitten off. Lichens and mosses are also eaten if they are present and nearby pika dwellings. Ochontids use pathways to travel between feeding grounds. [Source: Dana Jordan, Humboldt State University, Animal Diversity Web, University of Michigan ~]

“Because pikas do not hibernate and food storage often runs low during late winter, they typically forage continuously during the winter months. When snow cover is heavy, pikas dig tunnels from their burrows to tree trunks. In the absence of other forage, pikas may nibble away the tree bark. Two fecal types are produced, including a gelatinous, green excrement. To obtain vitamin B and other nutrients, pikas, like all lagomorphs, will consume their feces. ~

“Pikas are particularly vulnerable to weasels, canines, hawks, and owls and calling has evolved to alert nearby indivuals of approaching danger. Generally, there is a sentinel on the alert for strange sounds and movements. This individual often watches from a slope with an adequate view. Barks are initiated at the first sign of danger. Sentinals can escape to a nearby crevice for their own safety. Pikas usually take cover in the rocky debris when two short, distinctive calls, typical of an aerial predator, are given by the sentinel. When weasles are spotted, vocalization is generally restrained, and pikas hearing the call will silently escape and take cover. The strategy is different for avian and terrestrial predators because runways and tunnels are differentially accessible by these predators.” ~

Image Sources:

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, U.S. government, Compton’s Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

Last updated April 2016