Liomys salvini
Salvin's spiny pocket mouse

Liomys salvini is found along the Pacific slope in the southern Mexican states of Oaxaca and Chiapas south through Central Costa Rica. From the Pacific Slope, the range extends significantly inland in Southern Guatemala, Southern Honduras, and Nicaragua. It is usually found from the lowlands to elevations of 1500 meters.

(Reid, 1997)

Typically Liomys salvini are found in drier habitats than other tropical pocket mice (especially Heteromys desmarestianus, which live in wet tropical forests). They are found in dry tropical forests and in brushy, weedy fields. L. salvini are most often trapped along walls or rocks.

(Flemming, 1975, Reid, 1997)

Head and body length: 103-140 mm

Tail length: 97-144 mm

Hind foot length: 26-30 mm

Ear length: 12-16 mm

Liomys salvini is sexually dimorphic, with females averaging 39g and males averaging 51g. When males are sexually active their scrotal testes are greatly enlarged.

Liomys salvini is a small to medium sized rodent. Like other pocket mice, L. salvini 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, L. salvini is always grey or grey-brown dorsally with cream-colored underparts, forelegs, and feet. The darker dorsal fur is interspersed with dark spiny hairs and lighter, cream-colored hairs. The tail is approximately equal to the body length, bicolor, and nearly hairless (although it may have a short terminal hair tuft). In regions of overlap, L. salvini can be distinguished from other species by the lack of orange side stripes (/Liomys pictus/) and a lack of dark forelimbs (/Heteromys desmarestianus/). Body and tail proportions are also different between species.

(Reid, 1997, Flemming, 1983)

Liomys salvini are nocturnal, quadrupedal, and poor tree climbers. They are most often observed at night on forest floors or in weedy fields.

Liomys salvini is less social than other species of 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.

Liomys salvini individuals are intense seed hoarders and burrowers. Within each home range, an individual may construct several large burrow systems with several entrances. The seeds they collect are cached within their burrows and in shallowly-constructed pits around their home range.

Liomys salvini have been shown to enhance their diet through modification of cached seeds. Very hard and dry seeds do not make up a healthful diet but L. salvini individuals often collect and store these seeds through the dry season. Before storing, an L. salvini individual notches the seed coat with its incisors. Seeds with notches soften during the wet season and germinate into higher-quality food.

Experiments (Flemming 1977) have been conducted to test L. salvini's ability to withstand food and water deprivation. Perhaps as a result of adaptation to its normal habitat (dry forests), L. salvini was more able to withstand water deprivation than other tropical pocket mice. Water deprivation resulted in 3.4% daily body mass loss, and individuals survived at least one week without water. Food deprivation is also tolerated; individuals were able to lose 20% of their total body weight without any significant signs of weakness.

(Flemming, 1974, Flemming, 1977, Flemming, 1983, Reid, 1997)

Although Liomys salvini eat some insects, they are mainly a seed-eaters. In Costa Rica, L. salvini favors the seeds of the buttercup tree (/Cochlospermum vitifolium/) during the dry season. During other seasons they eat the seeds of many other species, including the poisonous seeds of guanacaste (/Enterolobium cyclocarpum/). Seeds are located by odor and they can reportedly locate seeds that are buried in dung.

(Flemming, 1983, Flemming, 1975, Reid, 1997)

No negative impacts have been reported.

Liomys salvini may be important in supporting diverse faunas, dispersing tropical forest seeds, and in insect control.

(Flemming, 1983)

Liomys salvini has no special conservation status, but is presumably negatively impacted by deforestation and habitat destruction. In dry forested areas it is still locally common.

Reid (1997)

T. H. Flemming calls Liomys salvini a "key industry" animal of the tropical forests. Because it is so abundant, the pocket mouse is an important food source for diverse groups of carnivorous animals including birds, snakes, and small cats. Because it is an avid seed hoarder, L. salvini is also an important disperser of seeds. L. salvini may also make a contribution to the control of insect larvae, although no study has suggested that this benefits human farming or forestry systems.

(Flemming, 1983)