Species › Mammals › Mountain Beaver

Mountain Beaver

Aplodontia rufa

UncommonMammal
Illustration of Mountain Beaver (Aplodontia rufa)

The Mountain Beaver is neither a true beaver nor a mountain dweller but is in fact the world's most primitive living rodent—the sole surviving member of a once-diverse family with a fossil record stretching back 40 million years. It burrows in moist forests along the Pacific Coast and must drink water frequently, unable to concentrate its urine effectively. Mountain beavers are important ecosystem engineers in Pacific Coast forests, creating habitat features used by many other species.

Habitat
Moist Pacific Coast conifer forests with dense fern understory
Diet
Ferns, forbs, bark, and needles of conifers
How common
Uncommon

Best time to see a Mountain Beaver

The best time to see a Mountain Beaver is April–August, when about 65% of U.S. sightings happen, based on 375 research-grade iNaturalist observations.

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