Ochotona collaris

Geographic Range

Collared pikas, Ochotona collaris , are found in the mountainous regions of central and southeastern Alaska, in the Yukon-Tanana uplands to the Chigmit Mountains, and from the Richardson Mountains north of the Artic circle in the Yukon, west of the Mackenzie River in the Northwest Territories, and south into northwestern British Columbia (MacDonald and Jones, 1987).

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Collared pikas most commonly live in mountainous terrain that contains rock slides with large boulders and talus slopes. They favor the borders of talus slopes that are closest to meadows and patches of high quality vegetation. Collared pikas often colonize taluses that are on southwest facing slopes because they tend to have shorter period of snow cover and a longer plant growing season (Franken and Hik, 2004a). They also have been recorded inhabiting areas near sea level in southern Alaska and British Columbia (MacDonald and Jones, 1987; Broadbooks, 1965). Their habitat is characterized as dominantly subalpine and alpine with strong seasonal variations and a short growing season for vegetation (June to August).

• Habitat Regions
• polar polar
• terrestrial terrestrial

• Terrestrial Biomes
• tundra tundra
• mountains mountains

Physical Description

Collared pikas share common characteristics with other Ochotona species, such as their small size (around 160 g), short round ears, and a concealed tail (Smith, 2008). Their hind limbs are slightly larger than the front limbs with 5 digits on each forefoot and 4 digits on each hind foot. They have hairy plantar surfaces on the feet. Their skulls are relatively flat, with narrow zygomatic arches, short narrow rostra, and a fenestrated maxilla. Distinctive skull characteristics of ochotonids are an absent supraobital process and spongy auditory bullae. The dental formula is; I 2/1 with 2nd peg like incisors, C 0/0, P 2/3, M 2/3 (MacDonald and Jones, 1987).

Collared pika ventral fur is creamy white and the dorsal fur is grayish. There are distinctive patches on the nape and shoulder forming a collar thus giving them their common name. The most diagnostic characteristic of the collared pikas is the creamy-buff fur patch over the facial gland which differs from their close relative, American pikas ( Ochotona princeps ), which has a brown patch. They have a common ano-genital opening, similar to birds, that is considered a pseudo-cloaca (MacDonald and Jones, 1987; Broadbooks, 1965). There is no sexual dimorphism (Smith, 2008). Sexing is done by investigating their pseudo-cloaca opening for evidence of genetalia.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

Collared pikas exhibit an alternating male-female distribution pattern of home ranges and tend to simply mate with their nearest neighbor (Franken and Hik, 2004b; Smith, 2008). Collared pikas are considered facultatively monogamous because most males are unable to control enough territory to gain access to multiple females.

• Mating System
• monogamous monogamous

The peak of the breeding season occurs in May and early June. Females have up to two litters a year that range between 2 to 6 young each and average 2.2 individuals weaned. Parturition tends to be synchronous. Parturition dates vary among years in response to the highly seasonal habitat. This strategy allows full advantage of the best conditions for growth of young. Gestation last between 3 to 4 weeks (30 days). Collared pikas reach adult size in 40 to 50 days. Both females and males can breed and produce young at one year of age. However, male reproductive success depends on gaining habitat and attracting females (Franken and Hik, 2004b). Juveniles will disperse within the natal talus patch immediately following the end of gestation to make their own territory (Franken and Hik, 2004a). Although, some species of pikas have be known to have post-partum estrous and produce a second litter per year further research is need to investigate if this is true for O. collaris .

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

Young collared pikas are born blind and nearly hairless. Female collared pikas are responsible for most of the parental investment and bear the brunt of energetic constraints of gestation and lactation. This could lead to a gradual decrease in litter size over the reproductive season due to pre-implantation losses, resorption of embryos, or losses during weaning which results in 2 to 3 young surviving to be weaned. Because it is not easy to distinguish between sexes by sight it is difficult to observe male investment in rearing offspring.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

Collared pikas can have a relatively long lifespan, up to 6 to 7 years (Smith, 2008). Collared pika over-winter mortality is high and populations are continuing to decrease over time (Morrison and Hik 2007; Franken and Hik, 2004b; Smith et al., 2004). Adult and juvenile survival is strongly linked to environmental conditions such as climate (Franken and Hik, 2004b). Adult survival is correlated with the Pacific Decadal Oscillation (PDO), with a time lag of 1 year. The timing and amount of snowfall and snowmelt are influenced by the PDO. This, in turn, alters growing season and food availability for collared pikas. Snow-pack is important in insulating pikas from temperature extremes during winter months. A low snow-pack year could expose collared pikas and their stored food to freezing ambient temperatures, but an earlier snowmelt could lengthen the growing season and allow more time to feed and store food for the next winter (Smith et al. 2004; Morrison and Hik, 2007).

Behavior

Collared pikas are one of several species of Ochotonidae that do not burrow; rather they take shelter in their talus habitats. They are asocial and constantly defend their territory by chasing away intruders. They are mainly solitary, although they may be seen in pairs occasionally. Collared pikas are diurnal and do not hibernate during the winter. They spend much of the day grazing and gathering vegetation for their winter cache, this foraging behavior is called "haying." Foraging distance varies according to degrees of predation risk (Holmes, 1991; Morrison et al., 2004). Pikas rarely forage more than 10 m from talus into meadows to collect food (Morrison, 2006). Individual pikas may make several haystacks within their home range and tend to inhabit the same location annually, usually under overhanging rocks, in crevices and along boulders. Collared pikas are also kleptoparasitic and will steal food from each other (Franken and Hik, 2004b; Smith, 2008).

• Key Behaviors
• terricolous
• diurnal diurnal
• motile motile
• sedentary sedentary
• solitary solitary
• territorial territorial

Home Range

Collared pikas live in low densities (2 to 15 individuals/ha) with a home range about 25 to 30 m in diameter (Morrison and Hik, 2007; Smith, 2008).

Communication and Perception

Collared pikas are very vocal, with both sexes emitting calls. The call of a pika is unmistakable once it has been heard. The call is a single, piercing note that sounds like “ank” or “ink” and can be heard for several hundred yards. When calling, pikas sit with their body hunched and noses pointed slightly in the air. Collared pikas vocalize frequently during hay gathering. After depositing food they will make one or two territorial calls from hay piles to neighboring pikas. Other forms of communication include chattering, a continuous clicking of teeth by males during reproductive season, and estrous calls by females (MacDonald and Jones, 1987). Another function of vocalization serves as a predator warning to neighboring pikas, territory defense, and also establishing and maintaining social structure. Unlike American pikas ( Ochotona princeps ), which can produce 9 different vocalizations, collared pikas do not have an extensive repertoire. Both territorial and predator calls produced sound approximately the same (Trefry, Ochotona thesis 2008).

• Communication Channels
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Like other pikas, collared pikas are an excellent example of an ecotone species, meaning their home and shelter are separated from their food storage (Broadbooks, 1965). Pikas are herbivorous and spend the summer months actively collecting a wide range of vegetation to subsist on during the winter months. Ochotona species, like other lagomorphs produce two kinds of fecal pellets: hard and soft. They consume their soft pellets to reduce the loss of nutritional value in their food. They also consume fecal pellets of other species such as hoary marmots ( Marmota caligata ) and ermine ( Mustela erminea ) (Broadbooks, 1965). Although they are primarily herbivorous, collared pikas have been recorded to consume birds as an opportunistic source of protein and fat (Krajick, 1998). If insufficient hay reserves are stockpiled in the summer, collared pikas may have to resort to eating lichens and other small plants in underground snow tunnels during winter.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Animal Foods
• birds

• Plant Foods
• leaves
• flowers

• Other Foods
• dung

• Foraging Behavior
• stores or caches food stores or caches food

Predation

Collared pikas have no natural defense against predators besides hiding in cracks, crevices, and under large boulders in talus. They forage close to their home burrows. There are several known carnivorous predators, including ermine, foxes, weasels, lynx, and coyotes. Also, numerous birds of prey such as eagles and owls will hunt collared pikas (Broadbooks, 1965; Holmes, 1991; Morrison et al., 2004).

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Ochotona collaris is a key species that is consumed by numerous predators. Their hay piles could provide food for other herbivorous mammals. Collared pikas, along with other herbivorous mammals like hoary marmots ( Marmota caligata ) impact grass and herbaceous plant species in their high elevation habitats (Koh and Hik, 2007).

Economic Importance for Humans: Positive

Collared pikas are interesting and unique members of their alpine habitats. Pika haypiles and fecal pellets may improve the chances of plant colonization on talus slopes and fertilize soils. Cached winter hay piles produced by other species of pikas are collected and harvested by farmers to feed domestic cattle and sheep in Siberia (Danell et al., 1998).

Economic Importance for Humans: Negative

There are no known negative effects of collared pikas on humans.

Conservation Status

The IUCN lists collared pikas as lower risk/least concern. While this suggests there is no concern for populations at this time, they could respond negatively to climate change. Collared pikas are sensitive to high ambient temperatures and are restricted to high elevation habitats that are declining in response to climate change (Smith et al., 2004).

Other Comments

The monogeneric family Ochotonidae comprises about one third the diversity of the Order Lagomorpha .

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Charlene Leininger (author), University of Alaska Fairbanks, Hayley Lanier (editor, instructor), University of Alaska Fairbanks .

References

Broadbooks, H. 1965. Ecology and distribution of the pikas of the Washington and Alaska.. American Midland Naturalist , 73(2): 299-335.

Danell, K., T. Willebrand, L. Baskin. 1998. Mammalian herbivores in the boreal forests: their numerical fluctuations and use by man.. Conservation Ecology , 2(2): 9. Accessed November 15, 2008 at http://www.consecol,org/vol2/iss2/art9 .

Franken, R., D. Hik. 2004. Influences of habitat quality, patch size, and connectivity on colonization and extinction dynamics of collared pikas Ochotona collaris. Journal of Animal Ecology , 73: 889-896.

Franken, R., D. Hik. 2004. Interannual variation in timing of parturition and growth of collared pika (Ochotona collaris) in the southwest Yukon. Integrated Comparative Biology , 44: 186-193.

Holmes, W. 1991. Predator risk affects foraging behavior of pikas: observational and experimental evidence.. Animal behavior , 44: 186-193.

Koh, S., D. Hik. 2007. Herbivory meditates grass-endophyte relationships. Ecology , 88(11): 2752-2757.

Krajick, K. 1998. Nunataks. National Geographic , December: 62-71.

MacDonald, S., C. Jones. 1987. Ochotona collaris. Mammalian Species , 281: 1-4.

Morrison, S., L. Barton, P. Caputa, D. Hik. 2004. Forage selection by collared pikas, Ochotona collaris, under varying degrees of predation risk. Canadian Journal of Zoology , 82: 533-540.

Morrison, S., D. Hik. 2007. Demographic analysis of a declining pika Ochotona collaris population: linking survival to broad-scale climate patterns via spring snowmelt patterns.. Journal of Animal Ecology , 76: 899-907.

Morrsion, S. 2006. Foraging ecology and population dynamics of collared pikas in southwestern Yukon.. Arctic , 59(1): 104-107.

Smith, A., N. Formozov, R. Hoffmann, Z. Changlin, M. Erbajeva. 1990. The Pikas. Pp. 14-26 in Rabbits, Hares and Pikas . Gland, Switzerland: International Union for Conservation of Nature and Natural Resources.

Smith, A., L. Weidong, D. Hik. 2004. Pikas as the harbingers of global warming.. Species , 41: 4-5.

Smith, A. 2008. Lagomorph Biology: Evolution, Ecology, and Conservation . Berlin Heidelberg: Springer-Verlag. Accessed November 15, 2008 at http://www.springerlink.com/content/n5m1687741615687/ .

2008. "IUCN Red List of Threatened Species" (On-line). Accessed November 17, 2008 at http:// www.iucnredlist.ord .