Salvin's spiny pocket mouse (''Heteromys salvini'') is a small to medium-sized

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

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 gen ...

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

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

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''. ''Heteromys ...

''.

Physical characteristics

Like other pocket mice, it has external, fur-lined pouches in its cheeks for carrying seeds and other materials. Although the darkness of the fur can vary quite a bit geographically, it is always grey or grey-brown dorsally with cream-colored underparts, forelegs, and feet. The darker dorsal fur is meshed with dark spiny hairs and lighter, cream-colored hairs. The tail is approximately equal to the body length, bi-color, and nearly hairless (although it may have a short terminal hair cluster). In regions of overlap, ''H. salvini'' can be distinguished from other species by the lack of orange side stripes and a lack of dark forelimbs.Goldman A., Edward. 1911. Revision of the Spiney Pocket Mice

Average size

*Head and body length: 103–140 mm *Tail length: 97–144 mm *Hind foot length: 26–30 mm *Ear length: 12–16 mm

Distribution

It occupies much of the Pacific coast and adjacent mountains of Central America (from Costa Rica to Guatemala) and southernmost Mexico, usually from the lowlands to elevations of 1500 meters.Reid, F. 1997. A Field Guide to the Mammals of Central America and Southeast Mexico. New York: Oxford University Press.

Habitat

''Heteromys salvini'' reaches its greatest abundance in a geographic range that is mostly

semiarid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

tropical lowland forest. It is a

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

species that lives in a variety of niches, including underground and in bushes, trees, rock clusters, and log shelters, but is most commonly found in brushy, weedy fields that provide shelter to its burrows and protection from

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

Diet

Although ''H. salvini'' eat some insects, they are mainly seed-eaters. In Costa Rica, it favors the seeds of the buttercup tree during the dry season. During other seasons these mice eat the seeds of many other species, including plants, corn, wheat, beans, castor beans, and the poisonous seeds of the guanacaste tree. Because they are not often satisfied with a single meal, they can be found with cheek pouches full of seeds that are stowed away in their burrows and used when food resources are scarce. Because they are nocturnal, they often locate seeds by sense of odor. They have also reportedly been known to locate seeds that are buried in dung.Flemming, T. 1983. Liomys salvini (Raton Semiespinosa, Guardafiesta, Spiny Pocket Mouse). Pp. 475-477 in D Janzen, ed. Costa Rican Natural History. Chicago: University of Chicago Press.

Reproduction

Reproduction occupies 6 months out of the year (January–June) with an average of 2 litters annually and 4 offspring per litter. During this time females undergo a remarkable increase in weight. Because they are a

precocial In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...

species, their life spans are short, resulting in a high turnover rate in the population. Most individuals will survive for only one year; a few individuals will live to be 15 to 18 months old.

Behavior

This species is less social than other pocket mice. In dry forest systems, home ranges of .20 ha overlap, but intolerance and aggression is shown to members of the same sex. This results in the clumping of female home ranges around male home ranges. Larger individuals are dominant over smaller individuals, and adults are dominant over the young of the year. Aggression does not vary according to season.Flemming, T. 1974. The population ecology of two species of Costa Rican heteromyid rodents. Ecology, 55: 493-510.

References

{{DEFAULTSORT:Spiny Pocket Mouse, Salvin's Salvin's Spiny Pocket Mouse Rodents of Central America Mammals of Mexico Salvin's Spiny Pocket Mouse Salvin's Spiny Pocket Mouse Taxonomy articles created by Polbot