The Mexican spiny pocket mouse (''Heteromys irroratus'') is a species of

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 ...

in the family

Heteromyidae Heteromyidae is a family of rodents consisting of kangaroo rats, kangaroo mice, pocket mice and spiny pocket mice. Most heteromyids live in complex burrows within the deserts and grasslands of western North America, though species within the ...

. It is native to Mexico and

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

in the United States where it is found in dry, scrubby habitats. The

IUCN 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 status ...

has assessed it 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 ...

". It was formerly placed in the genus ''Liomys'', which is now recognized to be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

and has been subsumed into ''

Heteromys ''Heteromys'' is a genus of rodents in the family Heteromyidae, commonly known as spiny pocket mice. It is the only extant genus in the subfamily Heteromyinae which also includes the extinct genera '' Diprionomys'' and '' Metaliomys''. ''Heter ...

''.

Description

There are seven

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of Mexican spiny pocket mouse and there is considerable differences in color and size between different populations. In general it is a medium-sized member of its genus ''

'', growing to a head and body length of about with a tail of about the same length. The

pelage A fur is a soft, thick growth of hair that covers the skin of almost all mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an ...

is composed of a mixture of stiff spines with soft hairs, but because the hairs lie flat, the spines are the more noticeable part of the coat. The upper parts of the head and body are greyish-brown and the underparts whitish. There is a pinkish or buff lateral line separating the two colors. Juveniles are grey and initially lack spines which grow through the coat later. The soles of the feet are haired and the Mexican spiny pocket mouse is unique in its genus in possessing five rather than six tubercles on the hind foot.

Distribution and habitat

The Mexican spiny pocket mouse is

endemic Endemism is the state of a species being found only 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 foun ...

to parts of Texas and Mexico. Its range extends from just north of the

Rio Grande The Rio Grande ( or ) in the United States or the Río Bravo (del Norte) in Mexico (), also known as Tó Ba'áadi in Navajo language, Navajo, is one of the principal rivers (along with the Colorado River) in the Southwestern United States a ...

southwards to the

Mexican Plateau The Central Mexican Plateau, also known as the Mexican Altiplano (), is a large arid-to-semiarid plateau that occupies much of northern and central Mexico. Averaging above sea level, it extends from the United States border in the north to the T ...

, its southernmost limit being Zapotitlán in the state of

Oaxaca Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 32 states that compose the political divisions of Mexico, Federative Entities of the Mexico, United Mexican States. It is divided into municipalities of Oaxaca, 570 munici ...

. It is found in dry shrubland at altitudes of up to . In regions where their ranges overlap, it occurs in drier, upland habitats than the

painted spiny pocket mouse The painted spiny pocket mouse (''Heteromys pictus'') is a species of rodent in the family Heteromyidae. It is found in Mexico and the northern tip of Guatemala. It was formerly placed in the genus ''Liomys'', which is now recognized to be parap ...

(''Liomys pictus''). It is not normally present in areas with less than of annual rainfall.

Parasites

The Mexican spiny pocket mouse is parasitized by the mouse botfly, ''

Cuterebra fontinella ''Cuterebra'', or rodent bots, is a genus of Botfly, bot flies that attack rodents and similar animals. Etymology The genus name ''Cuterebra'' is a blend of the Latin words ''cutis'' 'skin' and ''terebra'' 'borer' with apparent shortening of exp ...

''.

Behavior

Four different methods of locomotion are used by the Mexican spiny pocket mouse. The fastest is a kangaroo-like leaping gait, during which the mouse can cover 1.5 metres (5 feet) in a second. This pocket mouse is

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

and spends the day in a burrow, the entrance of which may be covered with leaves or an earth mound. The diet consists largely of seeds, particularly of hackberry (''Celtis'' sp.),

mesquite Mesquite is a common name for some plants in the genera ''Neltuma'' and '' Strombocarpa'', which contain over 50 species of spiny, deep-rooted leguminous shrubs and small trees. They are native to dry areas in the Americas. Until 2022, these ge ...

and other trees and shrubs. These are stored in

cheek pouch Cheek pouches are pockets on both sides of the head of some mammals between the jaw and the cheek. They can be found on mammals including the platypus, some rodents, and most monkeys, as well as the marsupial koala. The cheek pouches of chipmunk ...

es and carried back to the burrow. In laboratory studies it was found that this pocket mouse was unable to maintain its body weight unless it had access to water. Reproduction takes place during much of the year but seems to peak between August and November. Litter sizes range from two to eight with four young being typical.

Status

The Mexican spiny pocket mouse has a wide range and is common in suitable habitats within that range. The population size seems to be stable and no particular threats have been identified so 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 ...

lists its conservation status as being of "

References

{{Taxonbar, from=Q115792 Mexican Spiny Pocket Mouse Fauna of the Rio Grande valleys Rodents of Mexico Rodents of the United States Least concern biota of Mexico Least concern biota of the United States Mammals described in 1868 Taxa named by John Edward Gray Taxonomy articles created by Polbot