Let’s talk about how squirrels manage to soar through the air, even though they don’t have wings. A stretchy skin membrane between their limbs and a flattened tail help flying squirrels steer and glide—though, to be clear, they don’t actually fly.
You’ll get a look at the simple anatomy and clever tricks that make gliding possible. From unique wrist cartilage shaping their membrane to the way they aim and land, it’s all pretty fascinating.
We’ll also touch on different species, their habits, and a bit about how gliding evolved. Maybe you’ll start picturing these little acrobats in your own backyard.
How Flying Squirrels Glide
You’ll see how flying squirrels launch, stretch their skin membranes, and steer to land right where they want. They rely on a patagium and special wrist cartilage to tweak lift, drag, and direction during a glide.
The Gliding Process Step by Step
First, a flying squirrel climbs up to a high branch and faces its landing spot. You might spot it leaning forward, then pushing off with both hind legs, twisting its body toward the next tree.
As it jumps, the squirrel stretches out its fore and hind limbs. This exposes the patagium—a stretchy membrane—that catches air like a mini parachute and gives the squirrel its first lift.
Next, the squirrel shifts from a steep dive to a flatter path by angling its body and stretching the membrane even wider. You’ll notice it making tiny adjustments to its limbs, changing the glide angle and how fast it moves forward.
Right before landing, the squirrel tilts its body upright and boosts lift, slowing down for a nice, controlled grab onto the tree trunk.
Gliding Membranes and Anatomy
The patagium runs from the wrist down to the ankle, and sometimes all the way to the tail’s base. Imagine a soft, furry wing that opens up whenever the limbs spread wide.
Right behind the front limbs, you’ll find cartilaginous wrist bones. These bones bend upward, acting almost like wing tips, which helps the membrane keep a curved shape and makes the glide more stable.
Muscles along the sides and near the shoulders tighten or relax, letting the squirrel reshape the membrane as needed. The tail and the rear part of the membrane tweak pitch and yaw.
Small skin folds between the hind legs add some extra surface area—handy when the squirrel needs a little more lift for landing.
This setup lets flying squirrels glide pretty far—sometimes tens of meters—without needing to flap. They just use their body shape and those stretchy skin surfaces.
Aerodynamics and Phases of Gliding
A glide kicks off with a ballistic dive—gravity and the squirrel’s launch speed take the lead here. You’ll see low lift and a burst of forward speed, as the squirrel uses its height to gain momentum.
During the cruise phase, the patagium grabs more air, lift goes up, and the glide angle flattens out. The squirrel trades downward speed for more distance, constantly shifting its limbs to hold its height and speed.
For the landing, the squirrel tilts its body upward, which increases lift again. Drag ramps up, slowing things down for a vertical finish onto the tree trunk.
Researchers have watched these forces rotate from forward to upward and then rearward as the glide goes on. Every phase relies on little posture tweaks that shift lift and drag, keeping the squirrel’s path on track and the landing smooth.
Controlling Lift, Drag, and Steering
The squirrel controls lift by stretching its limbs and arching the patagium. More stretch and a bigger arch mean more lift; relaxing the membrane drops lift and makes the squirrel sink faster.
Drag increases when the squirrel tilts its body up or flares the edges of its skin. You’ll see them use these moves to slow down right before landing.
Steering is all about uneven limb positions, tail angles, and tweaking those wrist cartilages. If one forelimb stretches out more than the other, the squirrel rolls; twisting the tail creates yaw.
The wrist cartilages act like mini wing tips, stabilizing the glide and cutting down on unwanted rolling.
By mixing up membrane shape, limb moves, and tail shifts, flying squirrels pull off surprisingly precise landings—even on skinny trunks or tiny branches.
If you want more detail, check out this field summary on how flying squirrels manage lift and drag (https://asknature.org/strategy/how-flying-squirrels-control-glide/).
Flying Squirrel Species, Habits, and Evolution
Flying squirrels live in all sorts of forests across North America and Asia. You might wonder which species you could spot, where they sleep and eat, and how they got so good at gliding.
Overview of Flying Squirrel Species
Flying squirrels belong to the tribe Pteromyini in the squirrel family Sciuridae. There are about 50 species worldwide.
In North America, you’ll usually find two: the northern flying squirrel (Glaucomys sabrinus) and the southern flying squirrel (Glaucomys volans). Asia has more, including giant flying squirrels (genus Petaurista) and tiny dwarf species like Petaurillus.
Sizes really run the gamut. Some giants reach 30–60 cm and weigh over a kilo, while the dwarfs are only a few centimeters long. Most have big eyes for night vision and a furry patagium stretching between their limbs for gliding.
You can read more about their general traits at Britannica’s flying squirrel entry (https://www.britannica.com/animal/flying-squirrel).
Habitat and Nocturnal Lifestyle
Flying squirrels stick to the forest canopy, where tall trees make gliding between trunks possible. You’ll find them in temperate and tropical forests, especially in mature woods with big trees and lots of cavities.
They sleep in tree holes, rock crevices, or cozy leaf nests where branches meet trunks.
Most flying squirrels are nocturnal, so you probably won’t spot them during the day. At night, they leave their dens and glide quietly through the treetops.
North American Glaucomys sometimes come down to the ground to stash nuts, but most flying squirrels prefer to stay high up, dodging predators and saving energy.
Diet and Foraging Strategies
Flying squirrels eat all sorts of things, so you could call them omnivores. Your local Glaucomys might munch on nuts, fungi (especially underground truffles), seeds, buds, and even insects.
Northern flying squirrels eat a lot of fungi and help spread fungal spores across the forest, which is kind of cool.
Foraging ranges depend on the species and forest layout. Some stick close to home, gliding between a few trees near their den.
Giant species can cover long distances—sometimes hundreds of meters in a single glide. They rely on night vision and silent gliding to sneak up on food and move between feeding spots fast.
Evolution and Relationships to Other Mammals
Flying squirrels actually evolved from tree squirrels, and yep, they’re part of the rodent order Rodentia. Fossil records and anatomical clues suggest their story began in the Oligocene, which is probably when gliding adaptations popped up for the first time.
Their patagium and the special cartilage in their wrists help them steer as they glide. These features evolved within the squirrel family itself, not from some ancient ancestor far away on the tree of life.
Convergent evolution is pretty wild—other gliding mammals developed similar tricks. Take anomalures (Anomaluridae) in Africa, or colugos (order Dermoptera). They look a lot like flying squirrels, but they’re not actually related.
Instead, these groups came up with gliding membranes on their own, just to make the most of life in the forest canopy.
