- Lepus pusilla Pallas, 1769
Steppe Pika, Little Pika
Value of species
Subgenus Lagotoma. There are currently two recognized subspecies: Ochotona pusilla angustifrons (east of the Ural River) and O. p. pusilla (west of the Ural River) (Smith et al. 1990). O. pusilla was formerly included in O. nubrica, O. forresti, and O. osgoodi (O. thibetana subspecies) (Smith et al. 1990)). This is a unique form of pika, and based on molecular evidence it stands alone in its subgenus (Lissovsky 2014).
This is a widespread species. Ochotona pusilla is known "from the upper Volga River and southern Ural Mountains south and east to the border of China," Kazakhstan, and Russia (Smith et al. 1990). The westernmost extent of O. pusilla is the easternmost edge of the European continent (Smith 1994). Despite its presence in Europe, it is routinely left off European mammal lists (Smith 1994). However, "the range of this species has contracted significantly in historical times" (Smith et al. 1990). A population was recently discovered in western China (Shayilawu et al. 2009). The past distribution extended into western Europe during the Pleistocene, with a new specimen record extending its northern-most presence to Cumbria county in the UK (Fisher and Yalden 2004). By the onset of the Holocene, O. pusilla still occurred in Hungary. This distribution moved eastward, so that by the 10th century it occurred in the Ukraine and by the 18th century it could be found “between the Don and the Volga” and finally, “only east of the Volga” by the 19th century (Smith 1994). The cause for distribution contraction has been two-fold: 1) naturally occurring climate change from the Pleistocene to Holocene; and 2) anthropogenic changes like overgrazing and agriculture (Smith 1994).
Population densities of Ochotona pusilla vary spatially and temporally and may vary according to habitat quality (Smith et al. 1990). Populations were described as "common" to "very numerous" for several regions within its distribution (Ognev 1966). The Red Book of the Bashkir Autonomous Republic, Soviet Union characterized some of the European populations of O. p. pusilla as "rare" (Smith et al. 1990).
Ochotona pusilla is a burrow-dwelling species of pika that occupies steppe habitat, "found primarily in moist soil which is verdant with thick grass and bushes" (Smith et al. 1990). As a steppe dwelling species, O. pusilla is an excellent indicator for the general health of steppe ecosystems (Smith 1994). This species of pika constructs haypiles (Ognev 1966). It is unusual "in that it is frequently nocturnal" and "vocalizations are usually heard at late dusk and through the night" (Smith et al. 1990). The total length of this species is 15.3-21.0 cm (Sokolov et al. 1994). O. pusilla has one to thirteen young per litter (Smith et al. 1990). The number of litters per year varies according to the age of the female (Shubin 1965). Adult pikas can yield three to five litters per year, whereas yearlings only produce one to three litters (Shubin 1965; Smirnov 1982). Females will mature in four to five weeks, whereas males become mature after a year (Shubin 1965). The reproductive periodicity will vary yearly according the weather conditions (Sokolov et al. 1994). Gestation is approximately 22-24 days (Shubin 1965).