Humboldt’s Flying Squirrel

Humboldt's flying squirrel (Glaucomys oregonensis) is one of three species of the genus Glaucomys, the only flying squirrels found in North America. The squirrel was named after the naturalist Alexander von Humboldt == Taxonomy == Using genetic analyses, Arbogast et al. (2017) showed that Humboldt's flying squirrel, previously thought to be conspecific with the northern flying squirrel, was actually a distinct species. The San Bernardino flying squirrel subspecies (G. o. californicus) is considered a Critically Imperiled Subspecies by NatureServe. == Description == They do not actually fly but glide from tree to tree. They are similar in appearance to the northern flying squirrel, however, they are generally smaller and have darker pelage. They are good gliders but clumsy walkers on the ground. === Fluorescence === Under ultraviolet light, females and males of all 3 species of Glaucomys fluoresce in varying intensities of pink on both dorsal and ventral surfaces. The fluorescence is hypothesized to help the flying squirrels find each other in low light and mimic the plumage of owls to evade predation. This hypothesis has been challenged by Toussaint et al. (2022) who instead suggest that the pink luminescence is a byproduct of the body's waste management. Moreover, these…