Heather vole

The genus Phenacomys is a group of North American voles. The genus name comes from the Greek for "imposter mouse."

These animals live in forested, alpine and tundra areas, which often include plants of the heath family. They are small rodents with long fur and short ears, legs and tails. They eat green plants, seeds and berries in summer and bark and buds of shrubs at other times. Predators include mustelids, owls and hawks.

Some sources include the tree voles, genus Arborimus, in this genus. At one time, the two species of heather vole were considered to be a single species.

The complete list of living species is:

Phenacomys intermedius, known as the western heather vole is a small rodent with a short tail that very closely resembles the montane vole and was even called the "deceiver mouse " for this reason. The hair of the heather vole is mostly gray to brown but the underside hair color is white to gray. In addition, these voles have whiskers extending to about their shoulders. This mammal burrows and is most active during the evening and night. Western heather voles are mainly found in open coniferous forests that contain small shrubs or vegetation on the outskirts as well as meadows in British Columbia, Canada. This species of voles are relatively uncommon as only 52 were captured out of 659 total voles during a 3-year period in British Columbia while 366 Red-backed voles and 241 long-tailed voles were captured.

The summer and winter diet of heather voles is predominantly kinnikinnick, a small shrub with evergreen leaves that produces red berries. These herbivores also feed on soapberry leaves and fruits during the summer months. The winter diet of Phenacomys intermedius is bark of bush willow, dwarf birch,sheep laurel, and blueberry. Additionally, they do store food in piles at the entrances of burrows at night during the summer and winter then feed on the food during the day when it is safer.

The western heather vole breeding season is from May to August and may be potentially shortened in populations living in high-elevations. A maximum of three litters has been reported with a pregnancy period of about 19 to 24 days and an average of 3 to 4 offspring per litter. Although these reports are of captive western heather voles and larger litter sizes of up to 7 are possible in wild voles.

The range of western heather voles is restricted to the Pacific Northwest of North America, specifically Canada and they are the most common rodent in this area of the subfamily Microtinae. The range of western heather voles is not well known but their range is from west central British Columbia then south to California/New Mexico. There is an uncertainty of distribution such that they have even been found in parts of Alaska and this uncertainty is due to limited sample size of captured heather voles because they do not enter traps often.