Flying squirrels, encompassing over 50 species globally, are small to medium-sized rodents distributed across the forested regions of North America, Eurasia, and Asia. They do not fly like birds or bats but glide using a specialized furred membrane called a patagium, which stretches from their wrists to their ankles. This gliding ability allows them to move efficiently through their arboreal habitat, but as a small, soft-bodied mammal, the flying squirrel remains a vulnerable target in the forest food web.
Apex Predators of the Night Sky
The most significant threat to the flying squirrel comes from specialized nocturnal hunters, primarily various species of owls. Since flying squirrels are active almost exclusively at night, they are exposed to the stealth of night-hunting raptors. The Great Horned Owl, a formidable predator across North America, is particularly adept at preying on these squirrels, often intercepting them while they forage or glide.
Owls possess feathers with soft, fringed edges, allowing them to achieve virtually silent flight. This acoustic advantage means a gliding squirrel is unlikely to hear an owl approaching until it is too late. The Northern Spotted Owl and the Barred Owl also consume flying squirrels regularly, relying on keen night vision and directional hearing to pinpoint prey in the dark.
These aerial predators often wait on a perch before launching a silent strike, capturing the squirrel with powerful talons. Gliding makes the squirrel an exposed target in open air for a few seconds. Other raptors, such as certain forest hawks that occasionally hunt at dusk or dawn, may also take advantage of the squirrel’s activity periods.
Threats from the Trees and Ground
Predators that patrol the trees and the forest floor pose a risk to flying squirrels, often targeting them when they are not airborne. Tree-climbing mammals like raccoons, martens, and fishers are significant threats because they can access the squirrels’ den sites. Fishers, which are large members of the weasel family, are particularly agile in the canopy and actively raid tree hollows and cavities where squirrels nest.
These predators focus on raiding the nest cavity, where the squirrels are sleeping or raising young, rather than catching them mid-glide. Bobcats and foxes also hunt flying squirrels, usually catching them when they descend to the ground to forage or bury nuts. In the southern range, arboreal snakes, such as various species of rat snake, climb into tree cavities to consume both adult and young squirrels.
How Flying Squirrels Avoid Capture
The primary defense strategy for the flying squirrel is its strictly nocturnal lifestyle, which allows it to avoid the many diurnal birds of prey that hunt during the day. Their large, dark eyes are an adaptation for maximum light collection, aiding their navigation and predator detection in near-total darkness.
When a squirrel does encounter an aerial threat, its gliding ability is used to cover distance quickly and unpredictably. By adjusting the tension in the patagium and using its flattened tail as a rudder, the squirrel can execute sharp, ninety-degree turns in mid-air to evade an attacker. Upon landing, the squirrel immediately sprints to the opposite side of the tree trunk, placing the wood between itself and any pursuing predator.
Furthermore, many species exhibit communal nesting behavior, huddling in groups of up to twenty or more individuals, especially during colder months. This social structure provides a measure of collective vigilance and warmth, increasing the chance that at least one member will detect a threat. Flying squirrels also communicate using high-frequency ultrasonic calls that can warn other group members of danger without alerting predators.