Thursday, September 6, 2012

Gliders in the Night

It's a bird? It's a bat? It's a... flying squirrel! Have you ever seen one of these elusive creatures? Being that they are nocturnal, small, and very agile, flying squirrel sightings are relatively rare. If you are fortunate enough to spot one, you are treated to the sight of a very cute and clever little rodent, with giant eyes and cinnamon-colored fur. So where can you find these little guys?

Flying squirrel at a bird feeder
Image courtesy of
In Wisconsin, we are lucky to live amongst two different species of flying squirrels: the northern flying squirrel (Glaucomy sabrinus) and the southern flying squirrel (Glaucomy volans) - click here for a range map. They are difficult to distinguish (adult northerns are larger and browner, while southerns are slightly smaller and grayer), and because they only emerge at night, it is especially difficult to get a good look at their characteristics and coloring. They may den in houses or barns, but are most commonly found in coniferous and mixed forests. This time of year, the little ones born in mid-summer are just being weaned and leaving their nests.

Image courtesy
How can you tell a flying squirrel from one of Wisconsin's more commonly-sighted species? First of all, they are only active at night (unless disturbed). They spend their days holed up in a nest in a nook or cranny of a tree, usually guarding their young, grooming and playing. They have slightly smaller tails, which they use as a stabilizer and brake while "flying." They also have large eyes and ears, which help them to navigate in the dark. Finally, look for extra skin folds between their front and back legs. This furry membrane, called a "patagium," is what they use to glide from tree to tree. This amazing acrobat can glide up to 150 feet in one swoop! Unlike bats, which have actual wings, "flying" squirrels are merely gliding - also called "volplaning." They climb high into a tree and leap with their legs extended and patagium outstretched, descending in a gentle curve towards another tree, where they swing upward and land. Watch a glide in action and a really cool slo-mo landing! You may also see northern flying squirrels hopping around on the ground. Even if you have trouble spotting these little leapers, they are quite social, and you can often hear them chatting and scurrying around in the dark.

Although they are nestled up napping most of the day, flying squirrels keep very busy at night - one squirrel can store up to 15,000 nuts in a season! They mainly feast on nuts and seeds, along with fruits, mushrooms, buds, and even eggs, small birds, or carrion. Their predators include cats, foxes, weasels, martens, owls, snakes, and hawks.

For more on these fascinating flyers, visit, to find some awesome videosimages, an art gallery, fun facts, and more! You can also find them on this Wisconsin Forest Wildlife poster and click for more info. Learn how to build a nestbox to see if you can attract these gregarious gliders to your own yard!