Western Harvest Mouse - Reithrodontomys megalotis
Global Rank:
G5
State Rank:
S4
Agency Status
USFWS:
none
USFS:
none
BLM:
none
CFWCS Tier:
3
General Description
The relatively small western harvest mouse averages 5 1/2 inches long and less than 1/2 ounce in weight. Its scaly tail comprises more than half of its length. The upper fur and tail color appears grayish brown, with a darker midline and buffy sides. Below, tail and body are white or grayish. Along with the nearly hairless bicolored tail, large ears and a groove running down the front of each incisor help differentiate the western harvest mouse from similar mammals.
Diagnostic Characteristics
See hoofer et al. (1999) for information on discrimination between r. megalotis and r. montanus using cranial characters.
Distribution
Montana Range
Observations in Montana: 158
Montana CountiesBig Horn, Carbon, Carter, Chouteau, Custer, Dawson, Fallon, Fergus, Garfield, McCone, Petroleum, Phillips, Powder River, Prairie, Richland, Roosevelt, Rosebud, Stillwater, Sweet Grass, Treasure, Wheatland, Yellowstone
Migration
Non-migratory.
Habitat
Dense grassy areas, sage-grassland.
Food Habits
Granivorous, also consumes some herbaceous materials and in- sects.
Ecology
Tolerant of conspecifics.
Reproductive Characteristics
Ave. 4.0 young/litter (n=2). In warmer parts of range breeds year round. Probably Mar-Oct in MT. Females are sexually mature in 4 months, polyestrous, several litters year.
Citations & Sources
- Burt, W. H. and R. P. Grossenheider. 1964. A field guide to the mammals. 2nd edition. The Peterson Field Guide Series. Houghton Mifflin Co., Boston, MA.
- Foresman, K.R. 2001. The wild mammals of Montana. Special Publication No. 12. American Society of Mammalogists
- Kritzman, Ellen B. 1977. Little mammals of the Pacific Northwest. Pacific Search Press, Seattle, WA.
- Zeveloff, S. I. 1988. Mammals of the Intermountain West. Univ. of Utah Press, Salt Lake City, Utah.