Red Tree Vole

Description

Red tree voles are small rodents with reddish-brown to cinnamon fur on their backs and white coloration on their bellies. They have long black or brown tails and rounded ears. Young red tree voles generally have dull brown coats and gain more red coloration with age. Females are larger than males, but both tend to fall between six to eight inches in length. The tail makes up about a third of their body length. Adults weigh only one to two ounces.

Range

Red tree voles are found solely in Oregon. They live in coastal forests and along the western slope of the Cascade Mountains. Red tree voles, unlike most other voles, live in trees. Individual voles have very small ranges and tend to keep to the cover of one or a few trees. They prefer old, tall Douglas fir trees, but are occasionally found in forests of grand fir, Sitka spruce, and western hemlock. Red tree voles usually occupy the lower third of the tree crown, but nests have been discovered from 2 to 65 meters above the forest floor. They typically build their intricate nests on branches near to the trunks of trees, but some nests have been found in tree cavities as well. Nests have separate areas for feeding and using the bathroom, and there is also an escape route to the ground. They can only occupy forests with high levels of humidity and rainfall because they require the extra moisture to coat fir needles as their water source. Red tree voles avoid many ground-dwelling predators by taking to the trees. However, they still become dinner for raccoons, martens, fishers, raptors, and more commonly, the northern spotted owl.

Diet

Red tree voles feed almost exclusively on Douglas fir needles, but they have been seen nibbling on needles, twigs, and bark from other evergreen trees. They gather the needles at night and bring them back to the nest for a daytime snack. Unlike most animals, red tree voles don’t drink from ponds, puddles, streams, or other obvious sources of water. Instead they lick up moisture clinging to the surfaces of fir needles.

Life History

Breeding season for red tree voles lasts from February to September, but some still mate in the winter. One to three offspring are born per litter, and each will stay with their mother for about a month before venturing out on their own. Adults are generally solitary, although multiple nests are sometimes found in close proximity. Red tree voles are not well studied and their lifespan remains unknown. However, they rarely exceed one to two years of age.

Conservation

Red tree voles are threatened by habitat fragmentation from logging, fire, and development. Because the voles prefer old-growth trees in which to build their nests, young trees replanted to compensate for logging are not immediately suitable as habitat. Red tree voles are on the decline, and as such, they are a candidate for federal listing as endangered.

Fun Fact

Female red tree voles can become pregnant shortly after giving birth, which occasionally results in two separate litters living together in a nest.

Sources

Animal Diversity Web, University of Michigan Museum of Zoology

Klamath-Siskiyou Wildlands Center

NatureServe Explorer

The IUCN Red List of Threatened Species

U.S. Fish & Wildlife Office