Zacatecan Deer Mouse
Encyclopedia
The Zacatecan deer mouse, or southern rock deermouse, (Peromyscus difficilis) is a species of rodent
in the family Cricetidae
. It is found only in Mexico
, and is not considered endangered.
-like animals, weighing from 28 to 43 g (0.987670938943135 to 1.5 oz), with long tails, large ears, and a slightly elongated snout. They have a combined head and body length of 9 to 12.5 cm (3.5 to 4.9 in), but the tail is always always somewhat longer than the body, being from 9 to 14.5 cm (3.5 to 5.7 in) long. The female has six teats.
The upper part and flanks of the animal are typically ochraceous or buff, but in some subspecies may be brownish-red or have a heavy overlay of darker hairs that render the animal almost blackish in color. A clearly visible line runs along the flanks, while the underparts are generally paler, being whitish or pale grey. The area around the shoulders often bears a patch of fur with a slightly ochre or salmon color. There is also a narrow ring of darker fur around the eyes, emphasising their appearance. The tail has a similar color to the body, being buff or ochre above, and paler on the underside.
Zacetecan deer mice breed during the wetter parts of the year, from June to December. The female can produce up to three litters in a season with an average of three pups each. Females can reach sexual maturity within six months, so that some born in the early part of the breeding season may produce youg of their own before the end of the year.
and Sierra Madre Oriental
. In the north it reaches as far as southern Chihuahua and Coahuila
, and in the south, it can be found as far as northern Oaxaca
.
It inhabits hilly terrain from 2100 to 3100 m (6,889.8 to 10,170.6 ft) altitude. It generally prefers a semi-arid environment, such as chaparral
or dry brush. As it alternative name of "southern rock deermouse" implies, is often often found in rocky or broken terrain, where the common vegetation tends to be grasses, acacia
, and shrubs such as acuhual
. However, Zacatecan deer mice are also fairly common in montane forest dominated by juniper
, oak
, or pine
, and, at the other extreme, have been found in rocky deserts with plentiful cacti
.
, feeding on small invertebrates and the seeds of grasses and other local vegetation. Their principle predators include skunk
s, snake
s, owl
s, and ring-tailed cat
s.
. Genetic analysis has shown that its closest relative is the northern rock mouse
, which is sufficiently similar to the Zacatecan deer mouse to have been considered the same species until 1978.
Five subspecies of Zacatecan deer mouse are currently recognised:
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
in the family Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
. It is found only in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and is not considered endangered.
Description
Zacetecan deer mice are medium-sized mouseMouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
-like animals, weighing from 28 to 43 g (0.987670938943135 to 1.5 oz), with long tails, large ears, and a slightly elongated snout. They have a combined head and body length of 9 to 12.5 cm (3.5 to 4.9 in), but the tail is always always somewhat longer than the body, being from 9 to 14.5 cm (3.5 to 5.7 in) long. The female has six teats.
The upper part and flanks of the animal are typically ochraceous or buff, but in some subspecies may be brownish-red or have a heavy overlay of darker hairs that render the animal almost blackish in color. A clearly visible line runs along the flanks, while the underparts are generally paler, being whitish or pale grey. The area around the shoulders often bears a patch of fur with a slightly ochre or salmon color. There is also a narrow ring of darker fur around the eyes, emphasising their appearance. The tail has a similar color to the body, being buff or ochre above, and paler on the underside.
Zacetecan deer mice breed during the wetter parts of the year, from June to December. The female can produce up to three litters in a season with an average of three pups each. Females can reach sexual maturity within six months, so that some born in the early part of the breeding season may produce youg of their own before the end of the year.
Distribution and habitat
The Zacetecan deer mouse is found only in Mexico, where it inhabits the mountainous interior in and around the Sierra Madre OccidentalSierra Madre Occidental
The Sierra Madre Occidental is a mountain range in western Mexico.-Setting:The range runs north to south, from just south of the Sonora–Arizona border southeast through eastern Sonora, western Chihuahua, Sinaloa, Durango, Zacatecas, Nayarit, Jalisco, Aguascalientes to Guanajuato, where it joins...
and Sierra Madre Oriental
Sierra Madre Oriental
The Sierra Madre Oriental is a mountain range in northeastern Mexico.-Setting:Spanning the Sierra Madre Oriental runs from Coahuila south through Nuevo León, southwest Tamaulipas, San Luis Potosí, Querétaro, and Hidalgo to northern Puebla, where it joins with the east-west running Eje Volcánico...
. In the north it reaches as far as southern Chihuahua and Coahuila
Coahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...
, and in the south, it can be found as far as northern Oaxaca
Oaxaca
Oaxaca , , officially Estado Libre y Soberano de Oaxaca is one of the 31 states which, along with the Federal District, comprise the 32 federative entities of Mexico. It is divided into 571 municipalities; of which 418 are governed by the system of customs and traditions...
.
It inhabits hilly terrain from 2100 to 3100 m (6,889.8 to 10,170.6 ft) altitude. It generally prefers a semi-arid environment, such as chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
or dry brush. As it alternative name of "southern rock deermouse" implies, is often often found in rocky or broken terrain, where the common vegetation tends to be grasses, acacia
Acacia
Acacia is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, first described in Africa by the Swedish botanist Carl Linnaeus in 1773. Many non-Australian species tend to be thorny, whereas the majority of Australian acacias are not...
, and shrubs such as acuhual
Tithonia
Tithonia is a genus of flowering plants in the family Asteraceae. It includes 11 species, with a center of distribution in Mexico but with one species extending into the Southwestern United States and several extending into Central America. Two species, T. diversifolia and T...
. However, Zacatecan deer mice are also fairly common in montane forest dominated by juniper
Juniper
Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the...
, oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
, or pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
, and, at the other extreme, have been found in rocky deserts with plentiful cacti
Cactus
A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...
.
Ecology
Zacatecan deermice are well adapted for climbing, although not truly arboreal, and maintain separate home ranges, especially during the breeding season. Population densities peak at around 13 individuals per hectare, but may be much lower at drier times of the year. They are omnivorousOmnivore
Omnivores are species that eat both plants and animals as their primary food source...
, feeding on small invertebrates and the seeds of grasses and other local vegetation. Their principle predators include skunk
Skunk
Skunks are mammals best known for their ability to secrete a liquid with a strong, foul odor. General appearance varies from species to species, from black-and-white to brown or cream colored. Skunks belong to the family Mephitidae and to the order Carnivora...
s, snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s, owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s, and ring-tailed cat
Ring-tailed Cat
The ringtail is a mammal of the raccoon family , native to arid regions of North America. It is also known as the ringtail cat, ring-tailed cat or miner's cat, and is also sometimes mistakenly called a "civet cat"...
s.
Classification
The Mexican deer mouse belongs to the truei species group within the genus PeromyscusPeromyscus
The genus Peromyscus contains the animal species commonly referred to as deer mice. This is a genus of New World mouse only distantly related to the common house mouse and laboratory mouse, Mus musculus...
. Genetic analysis has shown that its closest relative is the northern rock mouse
Northern Rock Mouse
The Northern Rock Mouse is a species of rodent in the family Cricetidae.It is found in Mexico and the United States.-References:...
, which is sufficiently similar to the Zacatecan deer mouse to have been considered the same species until 1978.
Five subspecies of Zacatecan deer mouse are currently recognised:
- P. d. difficilis - Chihuahua, Sierra Madre Occidental, GuanajuatoGuanajuatoGuanajuato officially Estado Libre y Soberano de Guanajuato is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 46 municipalities and its capital city is Guanajuato....
- P. d. amplus - southern Hidalgo to northern Oaxaca
- P. d. felipensis - Valley of MexicoValley of MexicoThe Valley of Mexico is a highlands plateau in central Mexico roughly coterminous with the present-day Distrito Federal and the eastern half of the State of Mexico. Surrounded by mountains and volcanoes, the Valley of Mexico was a centre for several pre-Columbian civilizations, including...
and Cerro San Felipe - P. d. petricola - Sierra Madre Orientale
- P. d. saxicola - QuerétaroQuerétaroQuerétaro officially Estado Libre y Soberano de Querétaro de Arteaga is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 18 municipalities and its capital city is Santiago de Querétaro....
and northern Hidalgo