By Heidi Bossingham
Geographic Range
Perognathus fasciatus is found in north central United States and south central Canada. (Manning and Knox, 1988; Riddle, 1999)
Habitat
(8200 ft)
Olive-backed pocket mice reside in arid and semi-arid upland habitats. They are often found in thinly covered grasslands, and prairies that contain loose soil. They prefer forest edges, a habitat which provides the proper amount of cover, and are associated with blue gramma and wheat grass. (Bernhardt, 2002; Manning and Knox, 1988; Pefaur and Hoffman, 1974)
These animals are found in the following types of habitat:
temperate 
.
Terrestrial Biomes:
savanna or grassland ; forest ; scrub forest .
Physical Description
(0.28 to 0.49 oz)
(4.92 to 5.63 in)
Perognathus fasciatus is a small to medium-sized pocket mouse with long hind feet (measuring 16 to 19 mm). Individuals weigh between 8 and 14 g, and measure 125 to 143 mm from head to tail. (Riddle, 1999; Williams and Genoways, 1979)
The species takes its common name from the olive-gray fur on the dorsal part of the body. Thefur of the ventrum is light cream to white in color. Pelage coloration may vary slightly depending on the season and the age of an individual. Juveniles and adults that have freshly molted will be darker. This is because the hairs are tipped with black when they are new, but this tip often breaks off as the hair ages, givign an animals a more "buffy" look. Adults molt once a year, with males molting sooner than the females. (Williams and Genoways, 1979)
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: sexes alike.
Reproduction
Females of this species breed twice annually.
Breeding occurs between April and August.
Olive-backed pocket mice are polygynous. (Turner and Bowles, 1967)
Mating systems:
polygynous .
Breeding begins as the weather becomes warmer in late April or early May, and continues through late July or early August. Females are capable of producing two litters per year, consisting of three to six young. The gestation period is roughly one month long, and newborns are altricial. (Riddle, 1999; Turner and Bowles, 1967)
Information is not available on the duration of lactation for this species, nor the age of independence. However, these mice are very similar to other members of their genus, and so probably do not vary significantly from other members of their genus in regard to these characteristics. (Riddle, 1999)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous .
Information on parental care in this species is lacking in the literature. Because P. fasciatus is a mammal, we know that the female cares for the young, providing them with milk. The young are altricial, and like most rodents, must grow within the safety of the nest until they are able to move around their habitat. While in the nest, the mother undoubtedly grooms and protects the young. Male parental care patterns are not known for this species. (Riddle, 1999)
Parental investment:
no parental involvement; altricial ; pre-fertilization (protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (protecting: female).
Lifespan/Longevity
There is only a small proportion of this species which lives longer than 12 to 14 months. (Williams and Genoways, 1979)
Behavior
Locomotion of P. fasciatus is quadrapedial. These animals mostly relying on using hind limbs in a hopping fashion and touching down front limbs for balance. In the presence of danger, thes mice exhibit ricocheting. This is when all four feet are used in unison to jump away. (Bernhardt, 2002; Manning and Knox, 1988)
Perognathus fasciatus is known to construct tunnel systems with several chambers. A typical tunnel system consists of a main tunnel and summer/winter caches. Constuction of the tunnel seems to be determined by its later use. The summer portion of the burrow averages 30 cm deep whereas the winter portion can be up to 200 cm deep. On average, the area covered by a burrow is 6 m. (Bernhardt, 2002; Manning and Knox, 1988)
Thes mice spend much of the day in the burrow and become active above ground only at night. They do not appear to hibernate but do become less active beginning in mid-fall. (Bernhardt, 2002; Manning and Knox, 1988)
Home Range
The size of the P. fasciatus home range has not been reported.
Communication and Perception
Information is not available on the communication patterns in this species. However, other members of the genus are known to communicate with vocalizations. Tactile communication is undoubtedly important, especially between mates, mothers and their young, and competitors. Scent cues are not uncommon in rodents, and are probably present in this species.
Food Habits
Pocket mice are mainly herbivorous and granivorous, feeding on grasses, forbs, and seeds. However, they do occasionally eat insects. Food is carried in cheek pouches until it can be transferred into the burrow. Food caching is common. (Manning and Knox, 1988; Pefaur and Hoffman, 1974)
Animal Foods:
insects.
Plant Foods:
leaves; seeds, grains, and nuts.
Foraging Behaviors:
stores or caches food .
Predation
- owls (Strigiformes)
- rattlesnakes (Crotalus)
- coyotes (Canis latrans)
Owl pellets found containing P. fasciatus suggest that owls are major predators of this species. Carnivores (such as coyotes) and reptiles (such as rattlesnakes) are also known to feed on them. (Colorado Division of Wildlife, 2002)
Ecosystem Roles
Perognathus fasciatus is a host species for fleas, ticks, and mites. These animals also play a role as a prey species for owls, some carnivores, and some snakes. Through their caching behavior, they act as seed dispersers. (Colorado Division of Wildlife, 2002; Manning and Knox, 1988)
Key ways these animals impact their ecosystem:
disperses seeds.
Economic Importance for Humans: Negative
In general, rodents (collectively) can cause a lot of damage to crops and are also known for carrying diseases, and for harboring parasites which carry diseases. No specific accusations have been made against P. fasciatus, but is probably guilty of some of these infractions against humans.
Ways that these animals might be a problem for humans:
injures humans (carries human disease); crop pest.
Economic Importance for Humans: Positive
These animals are not known to be of economic importance to humans, although humans probably benefit from them because of their status as a prey species. Many animals that humans find interesting, such as owls and coyotes, prey upon these mice.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
Olive-backed pocket mice are not listed by CITES or IUCN.
Other Comments
None
For More Information
Find Perognathus fasciatus information at
Contributors
Heidi Bossingham (author), University of Wisconsin-Stevens Point.
Chris Yahnke (editor), University of Wisconsin Stevens Point.
Nancy Shefferly (editor), Animal Diversity Web Staff.
