Ochotona pallasii (Gray, 1867)

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Ochotonidae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 28-43 : 35-36

14.

Pallas’s Pika

Ochotona pallasii

French: Pika de Pallas / German: Mongolei-Pfeifhase / Spanish: Pica de Pallas

Other common names: Mongolian Pika

Taxonomy. Ogotoma pallasii Gray, 1867 ,

type locality not given. Identified by O. Thomas in 1908 as “Asiatic Russia—Kirgisen.” Incorrectly restricted by V. G. Heptner in 1941 to “southern parts ... Karkaralinsk Mountains ... north of Lake Balkhash,” Kazakhstan.

Often spelled pallasi, the correct spelling following Article 33.4 of the International Code on Zoological Nomenclature is pallasii. According to mtDNA and nDNA, O. pallasii belongs to subgenus Pika. The specimen that became the holotype of pallasii came to the Natural Museum in London without proper locality information. Heptner in 1941 unreasonably stated that this specimen originated in Kazakhstan, which started further confusion of names. For a long time, the name was assigned to the Kazakh race, until the skull of the holotype was analyzed. This nomenclatorial problem became obvious because two closely related taxa, O. pallasii and O. opaca , are now known to be paraphyletic relative to O. argentata after recent analysis of mtDNA and nDNA. Thus, O. pallasii and O. opaca were considered separate species, and the former retained the name pallasii. According to morphological study, O. pallasii includes hamica, pricei, and sunidica. Three subspecies were usually considered within O. pallasii, but that was based on tradition rather than specific analysis. Two taxa, hamica and sunidica, with restricted distribution at the Mongolian—Chinese border were listed as separate subspecies. Nevertheless, neither morphological data nor limited data on mtDNA (sunidica only) point to segregation of subspecies. Monotypic.

Distribution. Main range from SE Altai and Tuva (S Russia), through Mongolian Great Lakes Depression, to Gobi Altai in W & S Mongolia, but also several enclaves located in E Mongolia, S Mongolia (Trans-Altai Gobi) and N China (Dzungarian and Southern Gobi in Xinjiang and Inner Mongolia=Nei Mongol).

Descriptive notes. Head-body 160-230 mm, ear 15-27 mm, hindfoot 27-36 mm; weight 150-270 g. Pallas’s Pika is a large pika. Dorsal fur is ocherous gray to grayish brown. Ventral fur is sandy or whitish. Winter dorsal fur is yellowish gray; belly is whitish. Hairs above neck gland are brown. Ears are rounded, with faint light margins. Toe pads are not hairy. Skull is medium-sized, with big orbits and incisive and palatal foramens separated. Auditory bullae of Pallas’s Pika are a little larger than in allied species related to the Alpine Pika ( O. alpina ). Condylobasal lengths are 41-47 mm, skull widths are 22-26 mm, and skull heights are 15-17 mm. Pallas’s Pika has bigger orbits than all species allied to the Alpine Pika and the Northern Pika ( O. hyperborea ), and it lacks rufous in pelage. Compared with the Daurian Pika ( O. dauurica ), Pallas’s Pika has incisive and palatal foramens of skull separated, its skull is wider, space between auditory bullae is much wider, and toe pads can be clearly seen in fur. Morphological identification of Pallas’s Pika and the Kazakh Pika ( O. opaca ) is difficult.

Habitat. Dry steppes and semi-deserts at elevations of 1700-3100 m. Pallas’s Pika is a burrowing species, typically associated with stones and rocks but also bottoms of valleys or alpine steppe with a few or without rocks.

Food and Feeding. Pallas’s Pika feeds on green plants. It usually eats herbs around its burrow. Beginning in July, Pallas’s Pika hoards hay, usually storing it in special chambers in its burrow. Stored hay weighs 1:8-14 kg. During cold periods, Pallas’s Pika eats hay and grazes on dry vegetation; however, starting in January, it digs for and eats underground parts of plants, such as rhizomes and bulbs, and also eats lichens.

Breeding. Breeding of Pallas’s Pika starts in March-April and lasts 4-5 months. Adult females breed 2-3 times/year. Young females start breeding at 1-1-5 months old; young males do not participate in breeding. Each female has 3-10 embryos. Gestation is ¢.30 days, neonates are bare and born with closed eyes, and lactation lasts 15-20 days.

Activity patterns. Pallas’s Pika is diurnal and less active during daytime heat. Activity peaks in morning and evening when individuals feed and sunbathe for long periods of time. During cold periods, Pallas’s Pikas leave burrows only on sunny days. Winter activity peaks before midday and in early evening; c.30 minutes before sunset, they return to burrows. If firm snow prevents grazing, Pallas’s Pikas emerge on the surface only during warm middays.

Movements, Home range and Social organization. Pallas’s Pikas move openly aboveground; they often sit motionless near burrow entrances or on a stone. Home ranges are 100-720 m?*, depending on region. Winter home ranges decrease to 42-306 m®. Male Pallas’s Pikas might enlarge their home ranges during breeding season, up to 1500 m?*. Densities are 600-1800 ind/km?, maximum density can reach 3900 ind/km?, and peripheral density can be as low as 60 ind/km?®. Population numbers periodically oscillate 6-10 times. Home range boundaries are violently defended. Pallas’s Pikas are very aggressive to neighbors. Aggression includes biting or pursuit, and ritualistic behavior such as special poses. Pallas’s Pika is polygamous. Areas occupied are marked with trails and pyramids of pellets made on hillocks of earth. Pallas’s Pika has well-developed vocalization, including alarm calls and songs serving breeding and social behavior. Pallas’s Pika digs complicated burrows. Burrow has one breeding chamber, 4-12 storage chambers, and 5-42 entrances. Burrow depth is usually ¢.70 cm, and burrows cover 3-160 m*. Burrow openings leading to storage chambers are often closed with small stones. Burrows are often associated with large stones or bushes.

Status and Conservation. Classified as Least Concern on The IUCN Red List (as O. pallasii pricer).

Bibliography. Heptner (1941), Melo-Ferreira et al. (2015), Monkhzul (2005), Sokolov et al. (1994), Tarasov (1950), Thomas (1908a), Travina et al. (2000).

Figures

On following pages: 3. Tsing-ling Pika (Ochotona syrinx); 4. Gansu Pika (Ochotona cansus); 5. Nubra Pika (Ochotona nubrica); 6. Plateau Pika (Ochotona curzoniae); 7. Thomas's Pika (Ochotona thomasi); 8. Alpine Pika (Ochotona alpina); 9. Turuchan Pika (Ochotona turuchanensis): 10. Northern Pika (Ochotona hyperborea); 11. Manchurian Pika (Ochotona mantchurica); 12. Hoffmann's Pika (Ochotona hoffmanni); 13. Korean Pika (Ochotona coreana), 14. Pallas's Pika (Ochotona pallasii).

Distribution. Main range from SE Altai and Tuva (S Russia), through Mongolian Great Lakes Depression, to Gobi Altai in W & S Mongolia, but also several enclaves located in E Mongolia, S Mongolia (Trans-Altai Gobi) and N China (Dzungarian and Southern Gobi in Xinjiang and Inner Mongolia=Nei Mongol).