The red tree vole (Arborimus longicaudus ) is a rodent of the Pacific Northwest, found in the US states of Oregon and California. They were formerly known as Phenacomys longicaudus and have also been called the red tree mouse.
The red tree vole is a rodent in the family Cricetidae. It is found only in coastal forests of Oregon and northern California. They exclusively eat the needles of conifers, primarily Douglas-fir (Pseudotsuga menziesii ), though they have occasionally been reported to eat the needles of Sitka spruce (Picea sitchensis ).
Red tree voles are about 6-8 in long, including the tail. When they are young they exhibit a dull brown coat and develop a more reddish color with age. They are nocturnal and very difficult to see, but they can be detected by finding piles or wads of these resin ducts on the ground.
Both sexes of red tree vole build nests, though the maternal nests are considerably larger.
Red tree voles have small litters consisting of 1 to 4 offspring and a long gestation period of 28 days compared to other Microtines. Juveniles depend on their mothers for 47 to 60 days before complete independence. Females exhibit post-partum mating where they can breed within a few days of giving birth and it is common to find two separate litters living in the same nest. During peak breeding periods (winter and spring), males disperse and travel longer distances from home in search for females that are sexually receptive. Females tend to stay closer to their nests, therefore having smaller home ranges.
Their habitats in old forests have become a concern for the species. Logging and habitat fragmentation has determined their status as vulnerable on the list of sensitive species on the Oregon coast. They are vulnerable to timber harvest due to their arboreal lifestyle and their low reproductive rates contribute to the concern of the species becoming further threatened. They are an important food source for the threatened Northern Spotted Owl and have been listed as a "survey and manage species" under the Northwest Forest Plan (NWFP) in order to help manage the area's ecosystem.
