By John Saari
Geographic Range
The Texas mouse populates rocky portions of central Texas, northward into Oklahoma and extends into southern Kansas, Missouri and western Arkansas. These regions are the only natural habitats for Peromyscus attwateri (Sugg, et al 1990).
Habitat
Peromyscus attwateri inhabits rocky areas including cliffs and limestone outcrops with woody vegetation, such as the Edwards plateau of Texas (Davis & Schmidly 1994). Due to the threat of predators the Texas mouse can often be found in crevices along cliffs, under logs, fallen grass, weeds, and in heaps of driftwood. Junipers are the dominant vegetation in the rocky areas that they inhabit (Engstrom et al. 1989). (Davis and Schmidly, 1994; Engstrom, Etheredge, and Stone, 1989)
These animals are found in the following types of habitat:
temperate 
; terrestrial .
Terrestrial Biomes:
forest ; scrub forest .
Physical Description
(0.88 to 1.23 oz)
(7.36 to 8.58 in)
The Texas mouse is a medium sized Peromyscus. It is not distinctly bicolored, but does have a lighter shade on its underside; its ankles are usually darker or dusky, the dorsal color is brown with darker and mixed with blackish marks along the midline. The mouse's side is a pinkish cinnamon and it has a pure white underbelly. Peromyscus attwateri is about 198 mm in total length with the tail usually about 103 mm. Hind feet are 24 to 27 mm and adults usually weigh from 25 to 35 grams (Davis & Schmidly, 1994). (Davis and Schmidly, 1994)
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: sexes alike.
Reproduction
Attwater's mice can breed multiple times during a breeding season.
Breeding occurs from September to late winter.
Reproduction occurs during September through late winter in north Texas (Davis & Schmidly, 1994). The average number of young per litter is four, but can range from one to six. (Davis and Schmidly, 1994)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
At birth, the mouse has a mass of about 1.5 g. The young are born hairless with wrinkled, pink skin, closed eyes, and a pinnae that is folded over their ear. Juvenile hair begins to develop on the second day after birth. On the third day, the pinnae unfold with the ear canal opening after a week and a half. Eyes open after two weeks, and the young are weaned anywhere from day 25 to 35. At this time, the young usually leave the nest to live on their own, however, sometimes the mother will allow some young to live there for longer periods. Once weaned, the young usually leave the nest and become independent of their mother, although sometimes the mother will tolerate their presence for longer periods (Margulis 1998). (Margulis, 1998)
Parental investment:
altricial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female).
Lifespan/Longevity
The average lifespan of the P. attwateri is 6.8 months, but can live as long as 18 months. (Davis and Schmidly, 1994)
Behavior
When P. attwateri shares habitats with other species of mice, such as Peromyscus pectoralis, it has been found to be a generalist using the full range of its available microhabitats. While P. pectoralis was a specialist, only exploiting certain microhabitats (Engstrom et al. 1989).
The Texas mouse has several morphological adaptations for climbing and movement in trees; it has a long, tufted tail to use as a prop when climbing and for balancing. It also has relatively long hind feet. According to a study done by Engstrom et al. (1989), the P. attwateri that were followed travelled in the trees approximately 70% of the time. Evidence was also found that the species frequently took refuge in nests in trees. (Engstrom, Etheredge, and Stone, 1989)
Key behaviors:
scansorial; nocturnal ; crepuscular ; motile ; sedentary ; solitary .
Food Habits
The Texas mouse is omnivorous. It will eat a wide variety of plant and animal matter depending on what is available; seeds, fruits, flowers, nuts, and other plant products are the primary source of nutrition. It will also feed on grasshoppers, camel crickets, and beetles (Davis & Schmidly, 1994). (Davis and Schmidly, 1994)
Primary Diet:
omnivore .
Animal Foods:
insects.
Plant Foods:
leaves; seeds, grains, and nuts; fruit; flowers.
Predation
Texas mice, like other Peromyscus species, are common prey for a wide variety of predators including raptors, snakes, and foxes.
Anti-predator adaptations::
cryptic .
Ecosystem Roles
Texas mice are important and abundant small prey for predators in the ecosystems in which they live. Their predation on seeds impacts plant communities.
Economic Importance for Humans: Negative
Like other Peromyscus species, P. attwateri can carry and spread hantaviruses and other diseases, but these are rarely transmitted to humans.
Ways that these animals might be a problem for humans:
injures humans (carries human disease).
Economic Importance for Humans: Positive
Texas mice are important members of the ecosystems in which they live.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
The Texas mouse is presently abundant in its natural habitat and is a healthy species.
Other Comments
Peromyscus attwateri was classified as a subspecies of Peromyscus boylii until 1974. It was then classified by Schmidly to be a full species due to chromosomal differences and a difference in molar structure (Davis & Schmidly 1994).
Contributors
John Saari (author), Southwestern University.
Stephanie Fabritius (editor), Southwestern University.
