Melanistic red tree vole. Photo: J. Swingle

Red tree vole at experimental nest structure

Fitting a radio-collar on a red tree vole. Photo: Scott Graham

X-ray of a radio-collared red tree vole that was predated by a gopher snake.

Jim Swingle with red tree vole study specimens at the Museum of Vertebrate Zoological, University of California, Berkeley

Red Tree Vole Research
Our research projects primarily concern management implications and conservation of red tree voles. A distinct population segment of red tree voles in the north Coast Range of Oregon is currently a candidate species for listing under the Endangered Species Act. Red tree voles are most associated with old forest (>80 years old) and conservation status is primarily caused by loss of older forests throughout the Oregon Coast Range. We have been conducting research to better understand historical and current distribution, habitat modeling, landscape connectivity, and underlying drivers for more limited occurrence in younger forests compared to older forests. See publications page for recently published papers from our lab. Mark Linnell is the lead author on a paper that highlighted the potential importance of young forest (20–80 years old) as low-contrast matrix that may contribute to tree vole persistence at the landscape scale in providing connections with the more stable populations in old fores. We are evaluating this hypothesis by conducting multi-year surveys in young forest stands to better understand factors facilitating occupancy of young forests. Mark is also the lead author on a paper that provides evidence that the relative lack of complex structures (e.g., broken tops, large limbs, mistletoe brooms) used by tree voles as nest-building foundations limit occupancy of younger forests. We will continue to assess the forest structure component underlying tree vole distribution and are moving now toward analyses to understand how the spatiotemporal dynamics of predation may influence red tree vole populations and their distribution within a variety of forest types. 

Red tree vole at experimental nest structure

Stellar's jay predation of a tree vole

Short-tailed weasel predation of tree vole at experimental nest structure