Red Tree Vole – Oregon Conservation Strategy

A male red tree vole (Arborimus longicaudus) eating a Douglas fir needle. Red tree voles are rarely seen. They are nocturnal and live in Douglas fir tree tops and almost never come to the forest floor. They are one of the few animals that can persist on a diet of conifer needles which is their principle food. As a defense mechanism, conifer trees have resin ducts in their needles that contain chemical compounds (terpenoids) that make them unpalatable to animals. Tree voles, however, are able to strip away these resin ducts and eat the remaining portion of the conifer needle. Photo Credit: Michael Durham, https://www.flickr.com/photos/oregonwild/

Overview

Species Common Name Red Tree Vole
Species Scientific Name Arborimus longicaudus
Federal Listing Status Candidate for listing (North Oregon Coast population)
State Listing Status Sensitive

Ecoregions

Coast Range

Oregon’s Coast Range, known for its dramatic scenery, is extremely diverse, with habitats ranging from open sandy dunes to lush forests and from tidepools to headwater streams. It follows the coastline and extends east through coastal forest to the border of the Willamette Valley and Klamath Mountains ecoregions

Klamath Mountains

The Klamath Mountains ecoregion covers much of southwestern Oregon, including the Umpqua Mountains, Siskiyou Mountains, and interior valleys and foothills between these and the Cascade Range. The Rogue watershed has the largest population of any coastal watershed in Oregon (Jackson County, Josephine County, and a portion of Curry County). Several popular and scenic rivers run …

West Cascades

The West Cascades ecoregion extends from east of the Cascade Mountains summit to the foothills of the Willamette, Umpqua, and Rogue Valleys, and spans the entire length of the state of Oregon. It is largely dominated by conifer forests, moving into alpine parklands and dwarf shrubs at higher elevations.

Special needs

Red tree voles are arboreal rodents that inhabit dense, moist conifer forests. They prefer large stands and have a highly-specialized diet, primarily of Douglas fir needles. They require large branches for protection of nests, which are typically at least 50 feet above ground.

Limiting factors

Red tree voles have low reproductive rates, small home ranges, limited mobility, and low dispersal capabilities. They are vulnerable to habitat loss from timber harvest, wildfire, development, recreation, roads, and other human-caused disturbances.

Data gaps

Develop survey methods for this small, canopy-dwelling species. Estimate home range sizes, dispersal distances, and migration patterns. Improve understanding of habitat relationships, including effects of forest management on vole populations, breeding success in young forest stands, and stand requirements for persistence (e.g., minimum number or size of conifer trees, connectivity). Conduct genetic studies.

Conservation actions

Continue to monitor voles in response to forest management activities. Conduct surveys in forested lands prior to timber harvest, and protect high-priority sites. Management goals and protection for the red tree vole are generally thought to be compatible with those for the threatened Northern Spotted Owl and other late-successional forest species.