Flying Squirrels: A Field Note

By Hannah Harkness, NCRN I&M Science Communications Intern

Trail camera images of this southern flying squirrel were captured in March 2024 in the western 60 miles of C&O Canal National Historical Park. Along with skunks, coyotes and bobcats, it was drawn to check out some alluring bait—a raw chicken leg. But would a flying squirrel really eat a chicken leg? And what makes these rodents so special?

Recent photos taken from a trail camera in C&O Canal in March 2024 show a southern flying squirrel.

NPS

Southern flying squirrels are opportunistic scavengers. Their omnivorous diet includes insects, birds, small rodents, fruit, and seeds and they have an important role as seed dispersers.

Flying squirrels are named after their ability to “fly” from tree to tree. To do this they use loose flaps of skin attached from their wrists to ankles called a patagium to glide from place to place. Because these rodents are nocturnal, people often don’t see them.

Southern vs. Northern Flying Squirrels

Southern flying squirrel (Glaucomys volans)

Todd Belanger/iNaturalist CC BY-NC

Southern flying squirrels (Glaucomys volans) can be found across the National Capital Region (NCR) and are widespread and abundant across eastern forests. Measuring only ten inches from nose to tail, they can be recognized by their white belly fur and tan or brown fur along their backs. They are also quite vocal and make more call types than many other squirrel species, including in the ultrasonic range beyond human hearing.

In the NCR, northern flying squirrels (Glaucomys sabrinus) are rare. They live across a more restricted northern range, usually in coniferous forests and dense canopies. Slightly larger at 12 inches from nose to tail, these squirrels can be recognized by white and gray fur on their bellies and reddish fur along their backs. They are herbivores, and their diet mainly consists of seeds, nuts, and fungi. These squirrels are less adapted to urban environments than their southern relatives, and habitat loss and population decline have caused this squirrel to become a protected species in several states.

Fun Fact: Ultraviolet Fluorescence in Flying Squirrels

Under ultraviolet (UV) light, flying squirrel bellies glow (with what appears to human eyes as) bubblegum pink! Scientists theorize this is because they occupy low-light environments with more UV wavelengths and that the fluorescence could play a role in communication between individuals or camouflage from predators.

When shown under UV light, flying squirrels glow pink and blue.

Kohler et al. 2019

Flying Squirrels in NCR Parks

Southern flying squirrels have been documented in every NCR park, while northern squirrels have not yet been observed in the NCR. Forest fragmentation has significantly reduced the connectivity of wooded areas across the eastern US, and southern flying squirrels are better adapted to these changing environments than the northern variety.

Helping Flying Squirrels

We can support flying squirrel habitats by:

• Leaving snags (dead trees) and large trees with spacious hollow cavities in forests to allow for flying squirrel nests
• Increasing the number of canopy trees in forests to help reduce forest fragmentation
• You can even build your own flying squirrel nest box at home!

Further Reading

• Kohler, A.M., Olson, E.R., Martin, J. G., Anich, P. S. 2019. Ultraviolet fluorescence discovered in New World flying squirrels (Glaucomys). Journal of Mammology.
• Peeples, Gary. 2022. Snapshot: Applying a Gentle Touch to Improving Habitat for an Endangered Flying Squirrel.
• Sharron, Edmund. 2022. Species Spotlight: Flying Squirrels.