Pika [1] | |
---|---|
American pika (Ochotona princeps) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Lagomorpha |
Family: | Ochotonidae Thomas, 1897 |
Genus: | Ochotona Link, 1795 |
Type species | |
Ochotona daurica | |
Species | |
See text |
A pika ( /ˈpaɪkə/ PEYE-kə [3] ) is a small, mountain-dwelling mammal native to Asia and North America. With short limbs, a very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but with short, rounded ears. [4] The large-eared pika of the Himalayas and nearby mountains lives at elevations of more than 6,000 m (20,000 ft).
The name "pika" appears to be derived from the Tungus pika, [5] and the scientific name Ochotona is derived from the Mongolian word ogotno, оготно, which means pika. [6] It is used for any member of the Ochotonidae ( /ɒkətoʊnɪdeɪ/ ), [7] a family within the order of lagomorphs, the order which also includes the Leporidae (rabbits and hares). They are the smallest animal in the lagomorph group. [8] Only one genus, Ochotona [7] ( /ɒkəˈtoʊnə/ or /ɒtʃəˈtoʊnə/ ), is extant within the family, covering 37 species, though many fossil genera are known. Another species, the Sardinian pika, belonging to the separate genus Prolagus , has become extinct within the last 2000 years owing to human activity.
Pikas prefer rocky slopes and graze on a range of plants, primarily grasses, flowers, and young stems. In the autumn they pull hay, soft twigs, and other stores of food under rocks to eat during the long, cold winter. [9] The pika is also known as the whistling hare because of its high-pitched alarm call it gives when alarmed. The two species found in North America are the American pika, found primarily in the mountains of the western United States and far southwestern Canada, and the collared pika of northern British Columbia, the Yukon, western Northwest Territories and Alaska.
Pikas are native to cold climates in Asia and North America. Most species live on rocky mountainsides, where numerous crevices are available for their shelter, although some pikas also construct crude burrows. A few burrowing species are native to open steppe land. In the mountains of Eurasia, pikas often share their burrows with snowfinches, which build their nests there. [10] Changing temperatures have forced some pika populations to restrict their ranges to even higher elevations. [11]
Pikas are small mammals, with short limbs and rounded ears. They are about 15 to 23 cm (5.9 to 9.1 in) in body length and weigh between 120 and 350 g (4.2 and 12.3 oz), depending on species.
These animals are herbivores and feed on a wide variety of plant matter, including forbs, grasses, sedges, shrub twigs, moss and lichens. Easily digestible food is processed in the gastrointestinal tract and expelled as regular feces. But in order to get nutrients out of hard to digest fiber, pika ferment fiber in the cecum (in the GI tract) and then expel the contents as cecotropes, which are reingested (cecotrophy). The cecotropes are then absorbed in the small intestine to utilize the nutrients.
Collared pikas have been known to store dead birds in their burrows for food during winter and eat the feces of other animals. [12]
As with other lagomorphs, pikas have gnawing incisors and no canines, although they have fewer molars than rabbits. They have a dental formula of: 2.0.3.21.0.2.3 = 26. [13] Another similarity that pikas share with other lagomorphs is that the bottom of their paws are covered with fur and lack paw pads. [14]
Rock-dwelling pikas have small litters of fewer than five young, whilst the burrowing species tend to give birth to more young and to breed more frequently, possibly owing to a greater availability of resources in their native habitats. The young are born altricial (eyes and ears closed, no fur) after a gestation period of between 25 and 30 days. [10]
Pikas are active during daylight (diurnal) or twilight hours (crepuscular), with higher-elevation species generally being more active during the daytime. They show their peak activity just before the winter season. Pikas do not hibernate and remain active throughout the winter by traveling in tunnels under rocks and snow and eating dried plants that they have stored. [15] Rock-dwelling pikas exhibit two methods of foraging: the first involves direct consumption of food, and the second is characterized by the gathering of plants to store in a "haypile" of cached plants. [16]
The impact of human activity on the tundra ecosystems where pikas live has been recorded dating back to the 1970s. [17] Rather than hibernate during winter, pikas forage for grasses and other forms of plant matter and stash these findings in protected dens in a process called "haying". They eat the dried plants during the winter. [18] When pikas mistake humans as predators, they may respond to humans as they do to other species that do prey on pikas. Such interactions with humans have been linked to pikas having reduced amounts of foraging time, consequentially limiting the amount of food they can stockpile for winter months. [19] Pikas prefer foraging in temperatures below 25 °C (77 °F), so they generally spend their time in shaded regions and out of direct sunlight when temperatures are high. [19] A link has also been found between temperature increases and lost foraging time, where for every increase of 1 °C (1.8 °F) to the ambient temperature in alpine landscapes home to pikas, those pikas lose 3% of their foraging time. [19]
Eurasian pikas commonly live in family groups and share duties of gathering food and keeping watch. Some species are territorial. North American pikas ( O. princeps and O. collaris ) are asocial, leading solitary lives outside the breeding season. [20]
Pikas have distinct calls, which vary in duration. The call can be short and quick, a little longer and more drawn out or long songs. The short calls are an example of geographic variation. The pikas determine the appropriate time to make short calls by listening for cues for sound localization. [21] The calls are used for individual recognition, predator warning signals, territory defense, or as a way to attract potential mates. [22] There are also different calls depending on the season. In the spring the songs become more frequent during the breeding season. In late summer the vocalizations become short calls. Through various studies, the acoustic characteristics of the vocalizations can be a useful taxonomic tool. [23]
The average lifespan of pikas in the wild is roughly seven years. A pika's age may be determined by the number of adhesion lines on the periosteal bone on the lower jaw. The lifespan does not differ between the sexes. [24]
The 34 species currently recognized are:
Many fossil forms of Ochotona are described in the literature, from the Miocene epoch to the early Holocene (extinct species) and present (16.4-0 Ma [2] ). They lived in Europe, Asia, and North America.Some species listed below are common for Eurasia and North America (O. gromovi, O. tologoica, O. zazhigini, and probably O. whartoni).
Paleontologists have also described multiple forms of pika not referred to specific species (Ochotona indet.) or not certainly identified (O. cf. antiqua, O. cf. cansus, O. cf. daurica, O. cf. eximia, O. cf. gromovi, O. cf. intermedia, O. cf. koslowi, O. cf. lagrelii, O. cf. nihewanica). The statuses of Ochotona (Proochotona) kirgisica and O. spelaeus are uncertain. [2]
The "pusilla" group of pikas is characterized by archaic (plesiomorphic) cheek teeth and small size. [30]
The North American species migrated from Eurasia. They invaded the New World twice:
Ochotona cf. whartoni and small pikas of the O. pusilla group are also known from Siberia. The extant, endemic North American species appeared in the Pleistocene. The North American collared pika (O. collaris) and American pika (O. princeps) have been suggested to have descended from the same ancestor as the steppe pika (O. pusilla). [26]
The range of Ochotona was larger in the past, with both extinct and extant species inhabiting Western Europe and Eastern North America, areas that are currently free of pikas. Pleistocene fossils of the extant steppe pika O. pusilla currently native to Asia have been found also in many countries of Europe from the United Kingdom to Russia and from Italy to Poland, and the Asiatic extant northern pika O. hyperborea in one location in the middle Pleistocene United States. [2]
While Ochotona is the only currently living genus of Ochotonidae, extinct genera of ochotonids include † Albertona , † Alloptox , † Amphilagus , † Australagomys , † Austrolagomys , † Bellatona , † Bellatonoides , † Bohlinotona , † Cuyamalagus , † Desmatolagus , † Eurolagus , † Gripholagomys , † Gymnesicolagus , † Hesperolagomys , † Heterolagus , † Kenyalagomys , † Lagopsis , † Marcuinomys , † Ochotonoides , † Ochotonoma , † Oklahomalagus , † Oreolagus , † Paludotona , † Piezodus , † Plicalagus , † Pliolagomys , † Prolagus , † Proochotona (syn. Ochotona), † Pseudobellatona , † Ptychoprolagus , † Russellagus , † Sinolagomys and † Titanomys . [2] The earliest one is Desmatolagus (middle Eocene to Miocene, 42.5–14.8 Ma [2] ), usually included in the Ochotonidae, sometimes in Leporidae or in neither ochotonid nor leporid stem-lagomorphs. [37]
Ochotonids appeared in Asia between the late Eocene and the early Oligocene, and continued to develop along with increased distribution of C3 grasses in previously forest dominated areas under the "climatic optimum" from the late Oligocene to middle Miocene. They thrived in Eurasia, North America, and even Africa. The peak of their diversity occurred during the period from the early Miocene to middle Miocene. Most of them became extinct during the transition from the Miocene to Pliocene, which was accompanied by an increase in diversity of the leporids . It has been proposed that this switch between ochotonids and larger leporids was caused by expansion of C4 plants (particularly the Poaceae) related to global cooling in the late Miocene, since extant pikas reveal a strong preference for C3 plants (Asteraceae, Rosaceae, and Fabaceae, many of them C3). Replacement of large areas of forests by open grassland first started probably in North America and is called sometimes "nature's green revolution". [2]
The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae and the Ochotonidae (pikas). There are 110 recent species of lagomorph of which 109 are extant, including 10 genera of rabbits, 1 genus of hare and 1 genus of pika. The name of the order is derived from the Ancient Greek lagos + morphē.
The Sardinian pika is an extinct species of lagomorph that was endemic to the islands of Sardinia, Corsica and neighbouring Mediterranean islands until its extinction likely in Roman times. It was the last surviving member of Prolagus, a genus of lagomorph once widespread throughout Europe during the Miocene and Pliocene epochs, whose closest living relatives are pikas of the genus Ochotona.
The collared pika is a species of mammal in the pika family, Ochotonidae, and part of the order Lagomorpha, which comprises rabbits, hares, and pikas. It is a small alpine lagomorph that lives in boulder fields of central and southern Alaska (U.S.), and in parts of Canada, including northern British Columbia, Yukon, and western parts of the Northwest Territories. It is closely related to the American pika, but it is a monotypic form containing no recognized subspecies. It is asocial, does not hibernate, and spends a large part of its time in the summer collecting vegetation that is stored under rocks ("haypiles") as a supply of food for the winter. Some individuals have been observed collecting and consuming dead birds as sources of fat and protein. Thousands of trips are made during July and August to collect vegetation for winter.
The American pika, a diurnal species of pika, is found in the mountains of western North America, usually in boulder fields at or above the tree line. They are herbivorous, smaller relatives of rabbits and hares. Pikas have two different ways of foraging; they either directly consume food or they cache food in piles for the winter (haying).
The Daurian pika is a small relative of rabbits and hares in the order Lagomorpha. It is well known for its “barking” alarm call, and for its peculiar habit of making hay to help survive the winter. There are 4 recognized subspecies, Ochotona dauurica annectens, O.d. bedfordi, O.d. dauurica, and O.d. mursavi. Daurian pikas, like other lagomorphs, are characterized by a secondary set of incisor teeth. They are sexually monomorphic, with thick reddish coats. Pikas have no external tail, and their ears are large and rounded. The auditory bullae, a feature of the skull of daurian pikas are small in comparison to many other pikas. This is thought to be related to their fairly low altitude habitat preference. They are considered keystone species within their habitat.
The Gaoligong pika is a species of mammal in the family Ochotonidae. It is endemic to China. Many of the general physical characteristics of the pika species, are shared by Gaoligong pikas. However, the Gaoligong pika is specifically characterized by unique physical characteristics, including a red-brown colored crown around the neck and black behind the ears. They can produce one litter per year and can live up to three years. Their behavior is currently undetermined due to limited information available about the species. This is due to the inaccessibility of their habitat.
Hoffmann's pika is a species of mammal in the pika family, Ochotonidae, that is endemic to Mongolia. It is currently listed as endangered by the International Union for Conservation of Nature (IUCN).
The Ili pika is a species of mammal in the family Ochotonidae, endemic to northwest China. After its discovery in 1983, it was studied for a decade. Increased temperatures, likely from global warming, and increased grazing pressure may have caused the rapid decline in population. According to IUCN last assessed in 2018, the Ili pika is now considered an endangered species, with approximately fewer than 1,000 left.
The steppe pika is a small mammal of the pika family, Ochotonidae. It is found in the steppes of southern Russia and northern Kazakhstan.
The Turkestani red pika is a species of mammal in the family Ochotonidae. The summer fur at its back is bright rufous and the ventral fur is white or ochraceous. The winter dorsal fur is pale brown and the ventral fur is white or light ochraceous in colour. It is found in the mountains of western Xinjiang in China, and sporadically also in the central Asian mountains in Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan. The female has a low fertility rate, and gives birth to offspring during the breeding season from spring to summer. She generally produces two litters each year, with two to six young. It is rated as a species of least concern on the International Union for Conservation of Nature Red List of Endangered Species, but it is considered to be near-threatened within the China part of its range.
Prolagus is an extinct genus of lagomorph. Over 20 species have been named, and the genus was abundant and widespread in Europe during the Neogene. However, by the end of the Middle Pleistocene, it was confined to a single species, the Sardinian pika, on the Corsica, Sardinia, and surrounding islands, where it survived into historical times. In North Africa and Western Asia, the genus is known from the Miocene and Pliocene. The scientific name may mean "before hares" or "primitive hares". Its taxonomy is disputed, with it either being considered a member of the family Ochotonidae, which includes living pikas, or the only member of the family Prolagidae.
Pallas's pika, also known as the Mongolian pika, is a species of small mammals in the pika family, Ochotonidae. It is found mainly in the mountains of western Mongolia.
The black pika or silver pika is a species of mammal in the family Ochotonidae. It was thought to be common to the Yunnan Province of China where it was first discovered in 2000, it is only known from four specimens. The validity of the species has been questioned, with some studies suggesting that the known specimens represent melanistic individuals of Forrest's pika.
The Tsing-ling pika is a species of pika endemic to the mountains in Central China. It inhabits mountainous forests and shrublands. It is a poorly known species.
Hypolagus is an extinct genus of lagomorph, first recorded in the Hemingfordian of North America. It entered Asia during the early Turolian and spread to Europe not much later, where it survived until the Middle Pleistocene. Though unknown in the Iberian Peninsula, fossils of this genus have been found in the Balearic Islands, suggesting an eastern migration during the dry period in the Mediterranean region known as the Messinian Salinity Crisis.
The giant pika or Wharton's pika is an extinct mammal species in the family Ochotonidae. It lived during the Pleistocene and early Holocene in northern parts of North America. Very similar forms have also been found also in Siberia.
Ochotona spanglei is an extinct species of pika, known from Late Miocene - Early Pliocene fossil from Oregon (USA). Fossils were also found in Nebraska referred to as Ochotona cf. spanglei.
Prolagus oeningensis is an extinct lagomorph and the type species of its genus, Prolagus. It lived from 15.97 to 7.75 Ma, existing for about 8 million years.
Translated by Will Downs Department of Geology Bilby Research Center Northern Arizona University October, 1990
3rd INTERNATIONAL MAMMOTH CONFERENCE, 2003: PROGRAM AND ABSTRACTS, Edited by John E. Storer
3rd INTERNATIONAL MAMMOTH CONFERENCE, 2003: PROGRAM AND ABSTRACTS, Edited by John E. Storer
document type Dissertation full text
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