The Chilean rock rat (''Aconaemys fuscus'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

in the family

Octodontidae Octodontidae is a family of rodents, restricted to southwestern South America. Fourteen species of octodontid are recognised, arranged in seven genera. The best known species is the common degu, ''Octodon degus''. Octodontids are medium-sized ...

. It is found in the high Andes of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

Description

The Chilean rock rat is a short-tailed rodent. Rock rats in the genus ''

Aconaemys ''Aconaemys'' is a genus of rodent in the family Octodontidae. It contains the following species: * Chilean rock rat (''Aconaemys fuscus'') * Porter's rock rat (''Aconaemys porteri'') * Sage's rock rat Sage's rock rat (''Aconaemys sagei'') is ...

'' are similar to those in the genus '' Ctenomys'' but not so specialised for life underground. The ears are rather larger, the claws on the front feet which are used for digging are smaller, and the edging of hairs on the hind feet, used for shifting loose soil, is reduced in size. The upper parts of the Chilean rock rat are dark brown, with the underparts ranging from reddish brown to white. Sample specimens described in 1966 and 1984, from two different locations, had a head-and-body length ranging from to , with the tail adding another – to the animal's total length. Its

karyotype A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is disce ...

has 2n = 56 and FN = 108.

Distribution and habitat

This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to parts of Argentina and Chile in the high Andes in South America. Its range extends from about 33°S to 41°S. In Argentina, it is restricted to thick forests of bamboo and ''

Nothofagus dombeyi ''Nothofagus dombeyi'', Dombey's beech, coigue, coihue or coigüe (from Mapuche language, Mapudungun ''koywe'') is a tree species native to southern Chile and the Andean parts of Argentine Patagonia. It is a fast-growing species that can live i ...

'', but in Chile it is found in monkey puzzle (''Araucaria'') and

southern beech ''Nothofagus'', also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere in southern South America (Chile, Argentina) and Australasia (east and southeast Australia, New Zealand, New Gui ...

(''Nothofagus'') forests, and above the tree line, usually among tussocky grass. It occurs up to about .

Ecology

The Chilean rock rat is a semi-fossorial species and constructs a network of shallow tunnels and runways with entrances every metre or so. These burrows resemble those of ''

Spalacopus The coruro (''Spalacopus cyanus'') is a species of rodent in the family Octodontidae. It is the only species in the genus ''Spalacopus''. The species is endemic to central Chile, where it has been found in a wide variety of habitats, from coast ...

'' and ''Ctenomys'' and are sometimes also used by '' Akodon longipilis'' and ''

Geoxus valdivianus ''Geoxus valdivianus'', also known as the long-clawed mole mouse or Valdivian long-clawed akodont, is a species of rodent in the tribe Abrotrichini of family Cricetidae found in the Valdivian temperate rain forests and Magellanic subpolar forests ...

''. It seems to be a

colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 au ...

species and feeds on roots and seeds, apparently specialising on the roots and seeds of ''

Araucaria ''Araucaria'' (; original pronunciation: .ɾawˈka. ɾja is a genus of evergreen Conifer, coniferous trees in the family Araucariaceae. There are 20 extant taxon, extant species in New Caledonia (where 14 species are endemism, ende ...

'' in Chile. It is mainly active by night but sometimes also by day. It stores food for use in winter when it is active, moving about under the snow.

Status

''A. fuscus'' has a wide range and seems to be plentiful. No particular threats have been identified and the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed its conservation status as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

References

{{Taxonbar, from=Q302133 Aconaemys Mammals described in 1842 Mammals of Argentina Mammals of Chile Taxonomy articles created by Polbot