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 relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

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 ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 almost 608 species, it is the second-largest family of mammals, and has m ...

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

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

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 ...

at elevations from on the eastern side of 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 ...

. The species is at least partly arboreal. It is distinguished from the

Brazilian arboreal mouse The Brazilian arboreal mouse (''Rhagomys rufescens'') is a South American rodent species of the family Cricetidae. It is found in the Atlantic Forest of southeast Brazil, often close to bamboo thickets. It can be distinguished from '' Rhagomys lo ...

(''R. rufescens''), the only other known member of ''

Rhagomys ''Rhagomys'' is a genus of South American rodents in the tribe Thomasomyini of the family Cricetidae. Two species separated by about 3100 km are known, from southeast Peru and Bolivia east of the Andes, and in the Atlantic Forest of southea ...

'', 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, an ...

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 (fingers) 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 '' pl ...

(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 in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primat ...

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 A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores wer ...

. 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 esca ...

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; 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 ...

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 ...

". 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