''Microryzomys altissimus'', also known as the Páramo colilargo or highland small rice rat, 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 genus ''

Microryzomys ''Microryzomys'' is a genus of rodent in the tribe Oryzomyini of family Cricetidae. It is closely related to '' Oreoryzomys'', '' Oligoryzomys'', and ''Neacomys''.Weksler, 2006 It contains two species, both restricted to the Andes: '' M. altissim ...

'' of family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has m ...

. It is found in

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

, and

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, but the Colombian segment may be a separate species.

Description

The Páramo colilargo has a greyish head, buffish upper parts and greyish-buff underparts and there is a clear demarcation between the dorsal and ventral colouring. The tail is dark above and pale below and is usually shorter than . The feet have whitish hairs on the upper surface, and the metatarsal pads on the soles are narrow. Compared to the closely related ''

Microryzomys minutus ''Microryzomys minutus'', also known as the montane colilargo or the forest small rice rat, is a species of rodent in the genus ''Microryzomys'' of family Cricetidae. It is found in Bolivia, Colombia, Ecuador, Peru, and Venezuela, but these popul ...

'', the skull is wider and more robust, with longer

incisive foramina In the human mouth, the incisive foramen (also known as: "''anterior palatine foramen''", or "''nasopalatine foramen''") is the opening of the incisive canals on the hard palate immediately behind the incisor teeth. It gives passage to blood vesse ...

and with longer rows of teeth. The diploid chromosomal count is 2n=57 and FN=58.

Distribution and habitat

This rodent is native to South America where it occurs in the high Andes of Ecuador, Peru and Bolivia. Its altitudinal range is between . Its range includes the Cordillera Central in Colombia where there is a separate population, and extends through the Cordillera Occidental and Cordillera Oriental of Ecuador, to the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

of northern Peru, as far south as Junin. Its typical habitat is moist subalpine forest and

páramo Páramo () can refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrower ...

, a high altitude grassland.

Status

The disjunct population in Colombia may be a separate species, and its conservation status would then need to be assessed separately, but the main population in Ecuador and Peru is large. ''M. altissimus'' may be threatened in places by deforestation and conversion of the páramo for agricultural use, but it is locally common, it has a wide range and occurs in several protected areas, so 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 rated its conservation status as "

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=Q1765818 Microryzomys Fauna of the Andes Rodents of South America Mammals of Colombia Mammals of Ecuador Mammals of Peru Páramo fauna Mammals described in 1933 Taxa named by Wilfred Hudson Osgood Taxonomy articles created by Polbot