Morgan's gerbil mouse (''Eligmodontia morgani''), also known as the western Patagonian laucha, is a South American species of rodent in the family Cricetidae. It is named for J. P. Morgan, one of the sponsors of the expedition that first identified the species.

Description

Morgan's gerbil mouse is a slender, mouse-like rodent with large ears and elongated hind feet. Adults measure from in total length, including a tail about long, and weigh from . Females are slightly larger than males. The fur is long and silky, and is a dull brownish-grey over the upper body, and pure white on the underside; a distinct line of yellowish fur runs along the animal's sides separating the brown from the white fur. The tail is hairy, and darker coloured above than below. Unlike most other species in the genus, the hind feet have a thick coat of fur on the soles.

Distribution and habitat

Morgan's gerbil mouse is found in southern Argentina, from southern Mendoza Province and Neuquén and Río Negro provinces in the north to the

Strait of Magellan The Strait of Magellan (), also called the Straits of Magellan, is a navigable sea route in southern Chile separating mainland South America to the north and Tierra del Fuego to the south. The strait is considered the most important natural pass ...

in the south. They are also found in the

Magallanes Magallanes may refer to: * Ferdinand Magellan (1480–1521), Portuguese explorer who led part of the first expedition around the world * Strait of Magellan, the strait between the Pacific and Atlantic Oceans, located in Chile Places * Magallane ...

and Tierra del Fuego Provinces of Chile. Within this region they are most common in open sandy grasslands and

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, ...

, at elevations between sea level and . There are no recognised subspecies.

Biology and behaviour

Morgan's gerbil mouse is primarily herbivorous, feeding on the seeds of shrubs such as '' Berberis'', '' Acaena'' and ''

Lycium ''Lycium'' is a genus of flowering plants in the nightshade family, Solanaceae. The genus has a disjunct distribution around the globe, with species occurring on most continents in temperate and subtropical regions. South America has the most spec ...

'', although they will also eat a small number of insects. They are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

, and construct nests by cutting holes into the bases of tussocks of grass, but do not use these nests to cache food. They are frequent prey for owls and other local predators, and are said to flee from attack by zigzagging with a gait that is part running and part leaping. The breeding season lasts from October to April in much of the range, but is shorter in more southerly, colder, climes. The litters of three to nine young reach sexual maturity at six to eight weeks of age. Individuals rarely live for more than nine months.

References

{{Taxonbar, from=Q306378 Eligmodontia Mammals of the Andes Mammals of Argentina Mammals of Chile Mammals described in 1901 Taxonomy articles created by Polbot