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Family Ochotonidae—Pikas

Certain characters in which this family differs from the Leporidae (hares and rabbits) are: hind legs scarcely longer than forelegs; ears short, approximately as wide as high; no postorbital process on frontal; rostrum slender; nasals widest anteriorly; maxilla not conspicuously fenestrated; jugal long and projecting far posteriorly to zygomatic arm of squamosal; no pubic symphysis; one less cheek-tooth above, the dental formula being i. 2/1, c. 0/0, p. 3/2, m. 2/3; second upper maxillary tooth unlike third in form; last lower molar simple (not double) or absent (in the extinct genus Oreolagus); cutting edge of first upper incisor V-shaped; mental foramen situated under last lower molar.

Genus Ochotona Link—Pikas

Revised by A. H. Howell, N. Amer. Fauna, 47:1-57, August 21, 1924.

Characters.—Five teeth (excluding incisor) in lower jaw; first cheek-tooth (p3) with more than one re-entrant angle; columns of lower molars angular internally; transverse width of any one column of a lower molariform tooth more than double the width of the neck connecting it to the other column.

Subgenus PIKA Lacépède

Characters.—Skull flattened; interorbital region wide; maxillary orifice roundly triangular; palatal foramina separate from anterior palatine foramina.

All of the living members of the family Ochotonidae belong to this genus. American pikas all belong to the subgenus Pika, which occurs also in Eurasia.

The distribution is boreal and the animals live in talus. This broken rock at the foot of a cliff provides interstices in which the animals live and store grass and herbs. These plant materials are cut for food and stacked in piles to dry in the sun, often beneath slabs of rock which protect the hay-piles from rain. Pikas are diurnal, active throughout the year, and have a characteristic call, "chickck-chickck." Young number two to five per litter.

Figs. 1-4. Ochotona princeps tutelata, Greenmonster Canyon, 8150 feet, No. 38519 MVZ, ♂, × 1.

Key to Nominal Species of Ochotona

• 1. North of 58° N