The gliding membrane, the patagium, runs from wrist to ankle and is tensioned by a rod of cartilage projecting from each wrist. Extending the limbs opens the aerofoil; adjusting one side banks the glide; the flattened tail acts as a stabiliser and airbrake. Glides usually cover a few metres, and descents of tens of metres have been recorded; the animal typically pitches up just before landing to shed speed, then scurries to the far side of the trunk.
Gliding is descent, not powered flight. The squirrel always loses altitude, and its glide ratio is modest compared with a bird or a bat. What it buys is a fast, quiet route between trees that avoids the ground, where predation risk is higher.
In 2019 researchers examining museum specimens reported that Glaucomys fur fluoresces pink under ultraviolet illumination, in all three species and in both sexes. Proposed explanations include communication or camouflage under low ultraviolet-rich twilight, but the function, if any, remains untested.