Life History

Red tree vole (Arborimus longicaudus)

Activity

Red tree voles spend most of the time hidden in their arboreal nests. Primarily noctornal, feeding is limited to around a half hour of intense foraging spread over three to four forays. Most foraging occurs at night, although brief day-time forays may be may by females tending young (Forsman et al. 2009).

Nest on branch

Nest

Nests are constructed in the canopy of their favorite trees; red tree voles prefer Douglas Fir but have also been found in several other conifer species (Benson and Borrel 1931, Maser 1981). Nests are built 1.8m to 48m above the forest floor, usually in a dense cluster of living branch and foliage. Nests are constructed out of twigs cut from the tree, although they have been known to take over the nests of other species (Maser 1981, Meiselman and Doyle 1996). Nests are comprised of nest (used for sleeping) and fecal (where voles defecate and urinate) chambers as well as connecting tunnels and are lined with discarded resin ducts (Maser 1981).

A pile of discarded resin ducts

Diet

Red tree voles diet consists almost entirely of Douglas Fir needles, although they also eat needles from other conifer species and young twig growth (Maser 1981, Carraway 1998, Forsman et al. 2009). Needles are consumed in a very specific and methodical manner... first the needles are bitten off at the base before the resin duct is removed using the vole's front incisors. The resin duct is disgarded or used as bedding while the remainder of the needle is consumed (Benson and Borrel 1931, Maser 1981).

Northern Spotted Owl (Strix occidentalis)

Predation

Predation is the source of most red tree vole mortality (Maser 1981, Swingle et al. 2010). Northern Spotted Owls are their primary predator, although many other predators have been documented including: Great Horned Owls, Northern Saw-whet Owls, Long-eared Owls, Barred Owls, Common Ravens, Steller's Jays, Northern Pygmy-Owls, Red-tailed Hawks, weasels, american martins, raccoons, and gopher snakes (Swingle, et al. 2010). Red tree voles greatest defense is their arboreal habitat, which limits the number of predators they are exposed too (Carraway 1998). Additionally, their small size and reddish coat make them difficult to spot in low light. To escape predators, voles will flee to a suitable hiding place or freeze and rely on their small size and cryptic color to avoid detection. Some may also launch themselves into free-fall until they either landing on a lower limb or the forest floor, apparently without injury. In addition to predation, sources of adult mortality include forest fires and human habitat destruction (timber logging), as well as disease and old age (Maser 1981).

Meadow Vole (Microtus pennsylvanicus) young; red tree voles are born similiarly hairless and helpless

Reproduction

Red tree voles are almost entirely solitary, each living in an independent nest, coming together only to mate (Maser 1981, Forsman et al. 2009). After a gestation period of around 28 days, females give birth to a litter of one to four, whom she cares for until they are one month of age (Forsman et al. 2009). At one month juveniles begin exploring outside the nest and leave the nest permanently by two months of age (Maser 1981, Forsman et al. 2009).

Conservation

Google Sites

Report abuse