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Chihuahuan Deermouse

Peromyscus polius
NT · Near threatened Rodentia Cricetidae
Size
9-11 cm + tail 9-11 cm
Weight
25-35 g
Activity
Nocturnal
Sociability
Solitary

Description

One of the least frequently seen Mexican mice, the Chihuahuan Deermouse is known from only a handful of high-altitude grassland localities in the state of Chihuahua, northern Mexico, with very few confirmed records since it was described over a century ago. Its scientific name, meaning grey in Latin, refers to the uniform greyish tone of its fur, distinct from the warmer brown of most of its relatives. It inhabits high-plateau grassland that is increasingly transformed by extensive livestock farming, which has considerably reduced the area of potentially suitable habitat available for the species. It is a prime example of how a rodent naturally restricted to northern Mexico's arid region can go decades almost unstudied despite its interest as an endemic species.

How to identify it

Small rodent with uniform greyish fur, distinct from the warmer brown tone of related species, alongside large eyes and well-developed ears. It differs from other Peromyscus species in northern Mexico by this highly characteristic greyish pelage tone and its restricted distribution in high-altitude grassland in Chihuahua.

Signs and tracks

Small track, 1.3-1.8 cm long, with 4 front toes and 5 hind toes. Small, elongated droppings 3-5 mm long, left scattered along surface runways through high-plateau grassland vegetation. Excavates shallow burrows beneath stones or roots, with the entrance partially concealed among dense vegetation.

Habitat and range

High-altitude grassland, generally above 2000 m altitude. Distributed across a small area of the state of Chihuahua, in northern Mexico.

Diet

Omnivorous, feeding on seeds, grasses and invertebrates in the high-altitude grassland it inhabits.

Behaviour

Solitary and probably nocturnal, with a home range centred on the high-plateau grassland it inhabits.

Conservation

Populations are generally considered stable within its known area, although declining locally due to the transformation of high-plateau grassland in parts of Chihuahua by extensive livestock farming.

Threats

Overgrazing and high-altitude grassland degradation caused by extensive livestock farming in northern Mexico.

Other accounts in Cricetidae

See all species accounts for rodents · Full species index

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