The long-tongued arboreal mouse (''Rhagomys longilingua'') is a

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

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

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of the 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 over 870 species, it is either the largest or second-largest family ...

. It is found in a variety of habitats, including dense forest, in

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

and

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

at elevations from on the eastern side of the

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

. The species is at least partly arboreal. It is distinguished from the Brazilian arboreal mouse (''R. rufescens''), the only other known member of '' Rhagomys'', by spiny fur and certain skull features such as the presence of beading in the

interorbital region The interorbital region of the skull is located between the eyes, anterior to the braincase. The form of the interorbital region may exhibit significant variation between taxonomic groups. In oryzomyine rodents, for example, the width, form, and ...

Description

The adult long-tongued arboreal mouse weighs in the range and has a tail that is nearly as long as the head-and-body length. The fur is short and dense, and consists of a mixture of long slender hairs and spines, giving the mouse a bristly appearance. The upper parts are olive-brown and the underparts are buffish ochre with fewer spines. The tail is dark above and slightly paler below, with rings of scales, and hairs increasing in length towards the tip and ending with a tuft of hairs. The fore feet have five long digits with broad, blunt tips and short, narrow claws that hardly project beyond the tips of the digits. The hind feet are short and broad and have five digits with blunt, calloused tips, the

hallux Toes are the digits of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being ''digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being ''plantigrade''; ...

(big toe) being shorter than the others and having a nail rather than a claw. The female has three pairs of

mammary gland A mammary gland is an exocrine gland that produces milk in humans and other mammals. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primates (for example, human ...

Distribution

The known range consists of four sites on the eastern slopes of the

in South America. The sites are in Peru and Bolivia, and the maximum distance between them is , and their altitudinal range .

Ecology

This mouse is probably an

insectivore file:Common brown robberfly with prey.jpg, A Asilidae, robber fly eating a hoverfly An insectivore is a carnivore, carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the Entomophagy ...

. Examination of the stomach contents showed that the diet includes flies, ants and moths, and the short gut and crested teeth reinforce this hypothesis. The morphology of the feet, the forward-pointing eyes and the short snout make it likely that it is an arboreal species. Three of the specimens examined were caught in

pitfall trap A pitfall trap is a trapping pit for small animals, such as insects, amphibians and reptiles. Pitfall traps are a sampling technique, mainly used for ecology studies and ecologic pest control. Animals that enter a pitfall trap are unable to es ...

s and the fourth one was a metre above the ground, in a clump of bamboo. The noticeably long tongue may be used to extract insects from crevices, but very little is known of this animal and its natural history.

Status

Although only known from a few isolated records, ''R. longilingua'' is listed by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

as being of "

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

". This is because of its tolerance of several types of habitats, and because in the absence of any particular threats, it seems unlikely that it is declining at a sufficient rate to qualify for being included in a more threatened category.

References

{{Taxonbar, from=Q1766049 Rhagomys Mammals of Peru Mammals described in 2003