Red-tailed Chipmunks (Tamias Ruficaudus) are common in Idaho and Montana, but numbers in Alberta, appear to be small and recent population trends are largely unknown. Small populations combined with a highly localized distribution has led to the inclusion of Red-tailed Chipmunks on the Blue List of species that may be at risk of declining to non-viable population levels in Alberta.
Red-tailed Chipmunks occupy relatively moist mixedwood and conifer stands, are arboreal in nature and have specific habitat preferences. Conifers are particularly important to Red-tailed Chipmunks because they are a major source of seeds for food, and large standing trees, 20-24 metres in height (living and dead), are often used as nesting sites. These particular chipmunks are most abundant where the forest understory is well-developed because vegetation, fruit, and seeds of shrubs and herbs are also important food sources.
Red-tailed Chipmunks are one of the larger species in the genus Tarnias. Their coat ranges in colour from light to dark gray on the back, belly, and rump; the shoulders and sides are reddish in colour, and the underside of the tail is bright orange or rust. They have alternating dark (black) and light (tawny to greyish or creamy white) stripes that run down their head and sides. The body and tail colour of these chipmunks are generally darker than other species but accurate visual identification is difficult. Compared to Least Chipmunks, Red-tailed Chipmunks are larger with a tail that is dark orange or red rather the light orange.
These chipmunks may occupy alpine habitats, but this is probably not a preferred habitat as Red-tailed Chipmunks are physically less suited to these higher elevations. In winter, Red-tailed Chipmunks spend the majority of their time in solitary burrows where they alternate between bouts of activity and torpor. During active periods, they eat seeds cached in the burrow during the previous summer. Large conifers are important seed sources, but Red-tailed Chipmunks also use seeds from shrubs such as Saskatoon, wild rose, and snowbrush, which may be particularly important when conifer seed production is low. During the plant-growing season, chipmunks will eat the leaves, flowers, and fruits of these plants as well as many other shrubs, forbs and grasses whereas autumn foraging may be restricted almost exclusively to conifers.
Little information is available regarding the influence of predation on Red-tailed Chipmunk populations or life history. The practice of transferring their young from burrows to tree nests before weaning may be a strategy to reduce losses to terrestrial predators during their early explorations from the nest. Some predators occurring in the mountains of southwestern Alberta include weasels, Martens, Coyotes, Red Foxes, and Bobcats. Woodland hawks are also possible predators.