Siberian Flying Squirrel

Fascinating facts about the Siberian Flying Squirrel

• A squirrel the size of a teacup can glide 50 metres through a dark forest without flapping once. The Siberian flying squirrel weighs just 170 grams but stretches a furry membrane called a patagium between its limbs, turning its body into a living parachute. It steers by twisting its flat, paddle-like tail and can bank hard enough to dodge trees at full speed. Most glides end in a controlled stall—the squirrel flips vertical and grabs bark with its claws just before landing, bleeding off momentum in the final metre. This is how it hunts: silent, invisible to owls, and impossible to trap.
• Its eyes are so enormous they're nearly spherical—each one bigger than its brain. Those 25-millimetre orbs are packed with photoreceptor cells that amplify starlight roughly 15 times better than human night vision, letting it spot a seed dropped on snow from 40 metres away in near-total darkness. In daylight the pupils shrink to slits. This radical eye design comes with a trade-off: flying squirrels can see motion beautifully but struggle to see colour—the cost of being a master of the dark.
• In winter it doesn't hibernate; instead it enters torpor every other night, dropping its body temperature by 30°C to save energy while the north spins into darkness. On cold nights it curls into a ball in a tree hollow lined with feathers stolen from nests, its heart rate plummeting from 200 beats per minute to just 10. By dawn it shivers back to warmth and hunts again. This on-off strategy means it stays tethered to stored food—cones and seeds cached in hundreds of hiding spots it somehow remembers.
• The Siberian flying squirrel is so cryptic that for decades scientists barely knew it was there. It was rediscovered in Finland in 1961 after being thought extinct for 50 years. Today it lives only in fragmented patches of old-growth spruce forest across the north—from Scandinavia to Hokkaido—each population isolated and shrinking as logging carves up the continuous canopy. The total population is unknown because the animal is nocturnal, silent, and smaller than a water bottle; some forests may be empty and we'd never see it.
• Its name is a lie—it cannot actually fly. What it does is glide, and it does it with a physics trick most mammals can't pull off. The patagium is anchored not just between limbs but extends to its ankles and even its claws, creating a wing-like sail that's proportionally larger than a hang-glider relative to body weight. This ratio lets it achieve one of nature's flattest glide angles: it can descend just 2 metres vertically for every 10 metres forward. For a creature hunted by nothing but owls in a frozen forest, silence and distance are the only survival strategy that works.

At a glance

About the Siberian Flying Squirrel

In the mystical veil of the boreal forest, the Siberian Flying Squirrel dances through the night, its silken membrane unfolding like a ghostly sail as it glides effortlessly between the towering tree trunks. With an ethereal gentleness, it navigates the shadowy realm, its large, round eyes shining like lanterns in the dark, as it pursues a solitary and nocturnal existence. As it alights upon a branch, its soft fur fluffed against the chill of the northern air, this enigmatic creature embodies the very essence of the forest's hidden magic.

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