Glaucomys oregonensis
Until recently, mammalogists classified two species of flying squirrels in North America. But, in 2017, a third was added with the formal description of the Humboldt’s flying squirrel (Glaucomys oregonensis). Though slightly smaller and darker, this cryptic species was once considered to be part of the northern flying squirrel (G. sabrinus) group but genetic studies and an in depth look at the penis bone changed that. Northern flying squirrels inhabit the boreal coniferous forests of the northeastern U.S., Canada, and Alaska as well as relictual habitat in the higher elevations of the Appalachian and Rocky mountains. The Humboldt’s flying squirrel is a specialist of the Pacific Slope’s coastal forests from southern California’s sky islands, north through the Sierra Nevada, Klamath Mountains, Coast Ranges, and Cascades in conifer and mixed-conifer forests.
