Related Biomes
Heather vole
Heather vole, Phenacomys intermedius
Phenacomys intermedius is an extant species of vole that probably evolved in North America. Currently it is widely distributed in Canada and the mountainous regions of the western U.S., but enjoyed a more easterly and southerly distribution during the last ice age. Because it is a boreal species, it is considered to be a good indicator of past climates; its recovery from late Pleistocene deposits in the Midwestern U.S. indicate that this region was cooler and wetter than it is today.
Heather vole, Phenacomys intermedius, study skins in the zoological collections of the Illinois State Museum, Springfield.
Length: 12.2-15.5 cm (4.8-6.1 inches)
Weight: 30-40 g (1-1.4 ounces)
Physical Description:
The heather vole is a small, mouse-like rodent with short tail, large hindfeet, and small ears and eyes. They have long, soft brown to grayish fur, with white to pale gray face and feet, and a silvery belly.
Heather voles are a boreal species that are found primarily in dry, open coniferous forests and grassy meadows of montane or subalpine forests, with shrubby understory to provide cover, although they also occur in more mesic habitats, such as moist, alpine meadows. They are called heather voles because they are often associated with the heather shrub, which grows in rocky, mountain habitats.
These animals are herbivores who eat a variety of plant materials, including foliage, bark, fruits, berries, seeds and lichens. Favored foods include willow, bearberry, blueberry, soapberry, dwarf birch and mountain cranberry (McAllister and Hoffman 1988). Heather voles commonly cache food near the entrances to their burrows, and caching activities occur in both summer and winter.
Heather voles are active year round. They live in underground burrows during the summer, with nests constructed of grass, moss or leaves. In winter, these animals build nests of leaves, grass and twigs on the ground surface near a bush, rock or stump. The winter nests are lined with shredded grasses, and branching lichens are used to seal them against snow (McAllister and Hoffman, 1988).
During the Wisconsinan, this vole had a much more southerly distribution that it currently enjoys, and has been found in sites as far south as Arkansas and Tennessee. They have also been recovered from sites throughout the U.S. Plains and Midwest, areas that are well outside of their current range.
As regional climates began to change towards the end of the Pleistocene, the heather vole followed its preferred boreal habitat northward. In the more mountainous regions of the U.S., boreal habitats reatreated into higher elevations, rather than higher latitudes, resulting in small, isolated populations of heather voles that still persist today.
Heather vole remains have been recovered from numerous paleontological sites througout the Midwest. These sites include, but are not limited to, Moscow Fissure in southern Wisconsin, Eagle Point in northwest Illinois, Prairieburg and Conklin Quarry in eastern Iowa and Craigmile in western Iowa, Peccary Cave in northern Arkansas, Cheek Bend Cave in central Tennessee, King Leo Pit Cave in southern Indiana and Sheridan Pit in northern Ohio. Given the short distances that these animals travel from their nests, the recovery of their remains from localities so far removed from their current range indicates that conditions in this region were much more favorable for these animals during the late Pleistocene than they are today.
- These tiny rodents are notoriously difficult to trap and rarely survive captivity, making it difficult to study them.
McAllister, J. and R. Hoffmann. 1988. Phenacomys intermedius. Mammalian Species 305: 1-8.
Related Animals:
