The alpine pika (Ochotona alpina) is a species of small mammal in the pika family, Ochotonidae. The summer pelage of different subspecies varies drastically but, in general, it is dark or cinnamon brown, turning to grey with a yellowish tinge during the winter. The alpine pika is found in western Mongolia, eastern Kazakhstan, and Russia (Tuva, Irkutsk, Altai, and Krasnoyarsk), as well as in China (northern Xinjiang and Heilongjiang), in very cold, mountainous regions. It is a generalist herbivore, and mainly forages on mosses, tree branches, pine nuts, and plant stems. It can emit three series of different vocalizations: a long call, a short call, and an alarm call. It is rated as a species of least concern on the IUCN Red List of Endangered Species.
Taxonomy
German zoologist and botanist Peter Simon Pallas originally described the alpine pika in 1773, in his work Reise durch verschiedene Provinzen des Russischen Reichs. It is a large species in the pika family, Ochotonidae, which consists of small mammals that have short ears, forelimbs very slightly longer than hindlimbs, and no external tail. There are four recognised subspecies: O. a. alpina (Pallas, 1773), O. a. cinereofusca (Schrenk, 1858), O. a. sushkini (Thomas, 1924), and O. a. changaica (Ognev, 1940).
The northern pika was included as a subspecies of the alpine pika by several authorities such as Vinogradov and Argyropulo in 1941; Argyropulo in 1948; Gureev in 1964; Corbet in 1978; Honacki, Kinman, and Koeppl in 1982; Weston in 1982; and Feng and Zheng in 1985. However, in 1973, Nikolai Vorontsov and Elena Ivanitskaya, pointed out the difference between their chromosome numbers. In 1980, Vladimir Sokolov and V. N. Orlov treated them as separate species, with their ranges overlapping in the Khenteii and Khangai Mountains in Mongolia. It is believed that after glaciation, the ancestors of the alpine pika were restricted to the borders of the Sayan and Altai glaciers, as well as the periglacial region of the major North Asiatic glaciation. The American pika and the collared pika were also included as subspecies of the alpine pika, by A.I. Argyropulo in 1948, A.A. Gureev in 1964, and G.B. Corbet in 1968. However, in 1981, M.L. Weston found out that they were morphologically different from the alpine pika. In 1986, Corbet and J.E. Hill treated them as separate species. O. a. sushkini was formerly considered a subspecies of the Pallas's pika, but is now a subspecies of the alpine pika. The Helan Shan pika and the Hoffmann's pika were formerly included as a subspecies of the alpine pika, but are now considered an independent species based on their chromosome number, morphology, and bioacoustic behaviour.
Description
The alpine pika measures in length, has long rounded ears ranging from in length, and weighs . The skull is narrow, measuring in length, and is less rounded and longer than the skull of the northern pika. In addition, the alpine pika has a longer snout, the back of the skull is bent more downward, and the bullae are deeper and much narrower, compared to those of the northern pika. The parietal bones (the two bones in the skull, which, when joined together at a fibrous joint, form the sides and roof of the skull) protrude at the front, forming a sloping angle with the interparietal bone (bone situated between the parietal bone and the supraoccipital bone located at the back and lower part of the skull), at the back. It has a large, thick cheek bone.
The summer pelage of different subspecies varies drastically but is generally dark or cinnamon brown. The back is dull, yellowish, ochre-grey in colour, with dark brown to black tips of the hairs. The latus (side of the body between the rib cage and the uppermost and largest part of the hip bone) is tinged with rust-red, and the underside is pale yellowish ochre. In winter, its pelage turns grey, with a yellowish tinge; the underside becomes greyish brown, and the anterior dorsum and head are tinged with yellow. The incisive foramen (funnel-shaped opening in the bony plate of the skull, located in the roof of the mouth, immediately behind the incisor teeth where blood vessels and nerves pass) are round, small, and are detached from the palatine foramen.
Despite geographic and seasonal variation, in sympatric zones, the adult alpine pika is larger than the adult northern pika by body measurements, and is usually more dull coloured.