Did you know that Alaska is home to squirrels that hibernate for up to eight months of the year, surviving temperatures that would freeze most other mammals solid? While you might associate squirrels with backyard bird feeders in the Lower 48, Alaska’s squirrel species have evolved remarkable adaptations to thrive in one of Earth’s most challenging environments.
Whether you’re exploring the boreal forests of the Interior, hiking the alpine tundra, or simply curious about the wildlife sharing Alaska’s vast landscapes, understanding these resilient rodents adds depth to your wilderness experience.
You’ll discover five distinct squirrel species across Alaska’s diverse ecosystems, each with unique behaviors, habitats, and survival strategies. From the chattering red squirrels defending their spruce cone middens to the ground-dwelling arctic squirrels that supercool their blood below freezing, these animals represent nature’s ingenuity at its finest.
This guide walks you through identifying each species, locating their preferred habitats, and recognizing the signs they leave across Alaska’s wilderness.
Arctic Ground Squirrel
The Arctic ground squirrel (Urocitellus parryii) stands as Alaska’s most widespread ground-dwelling squirrel and holds the distinction of being the only ground squirrel found throughout most of the state.
You’ll recognize these stocky rodents by their reddish-brown backs speckled with white spots, creating a distinctive mottled appearance that provides excellent camouflage against tundra vegetation.
These remarkable survivors inhabit open tundra, alpine meadows, and river valleys from the Brooks Range to the Alaska Peninsula. Arctic ground squirrels are highly social animals that live in colonies, and you’ll often spot them standing upright on their hind legs near burrow entrances, scanning for predators like golden eagles, foxes, and grizzly bears.
Their hibernation strategy represents one of nature’s most extreme adaptations, with body temperatures dropping below freezing for up to eight months—the longest hibernation period of any mammal.
Key Insight: Arctic ground squirrels can lower their body temperature to as low as -2.9°C (26.8°F) during hibernation, relying on brief periodic arousals to rewarm and prevent tissue damage.
During Alaska’s brief summer months, these squirrels work frantically to build fat reserves, often doubling their body weight before entering their winter dens.
You’ll find their burrow systems in well-drained soil, typically on south-facing slopes that receive maximum sun exposure. The entrance mounds are often surrounded by clipped vegetation, creating distinctive “haystacks” of dried plants they’ve harvested but not consumed.
If you’re hiking in Alaska’s Interior or arctic regions between May and September, watch for their characteristic alarm calls—a sharp, bird-like chirp that warns colony members of approaching danger. These vocalizations have earned them the colloquial name “sik-sik” among some Alaska Native communities, an onomatopoeia of their alarm call.
Northern Flying Squirrel
The Northern flying squirrel (Glaucomys sabrinus) brings an element of nocturnal mystery to Alaska’s forests, gliding silently through the darkness on skin membranes stretched between their limbs.
Unlike their ground-dwelling cousins, you won’t easily spot these secretive rodents during daylight hours—they’re strictly nocturnal and spend their days nestled in tree cavities or abandoned woodpecker holes.
These medium-sized squirrels possess soft, dense fur that’s cinnamon-brown on top and creamy white below, with large, dark eyes adapted for night vision.
The patagium—the furry membrane extending from wrist to ankle—allows them to glide distances up to 150 feet between trees, though they can’t truly fly.
You’ll find Northern flying squirrels in mature spruce, birch, and mixed coniferous forests throughout Southeast Alaska, the Interior, and Southcentral regions where old-growth forests provide essential habitat features.
Common Mistake: Many people assume flying squirrels are rare in Alaska because they’re seldom seen, but they’re actually quite common in suitable forest habitat—their nocturnal lifestyle simply keeps them hidden from casual observation.
These squirrels feed primarily on fungi, lichens, tree sap, insects, and bird eggs, playing a crucial role in dispersing fungal spores throughout the forest ecosystem.
During winter months, they don’t hibernate but instead remain active, sometimes forming communal nests where multiple individuals huddle together for warmth in especially cold weather.
If you want to observe Northern flying squirrels, your best opportunity comes after dark near mature forests. Look for their distinctive rectangular droppings, listen for soft chirping calls, or watch for their gliding silhouettes against the night sky.
Some Alaska residents attract them to feeding stations with peanut butter, sunflower seeds, or suet, though patience is required since they’re naturally wary of human presence.
Red Squirrel
The red squirrel (Tamiasciurus hudsonicus), also called the American red squirrel, is Alaska’s noisiest and most temperamental squirrel species. You’ll hear these feisty rodents before you see them—their rapid-fire chattering, harsh scolding calls, and foot-stomping displays announce their territorial presence throughout Alaska’s coniferous forests.
They’re smaller than you might expect, measuring just 11-14 inches from nose to tail tip, with rusty-red backs, white bellies, and distinctive white eye rings that give them an alert, wide-eyed appearance.
Red squirrels dominate the boreal forests across Interior Alaska, Southcentral, and Southeast regions, where spruce trees provide their primary food source.
Unlike ground squirrels, red squirrels don’t hibernate and remain active year-round, even during Alaska’s brutal winter months. Their survival strategy centers on creating massive food caches called middens—cone-shaped piles of discarded spruce cone scales that can measure 30 feet across and contain tens of thousands of stored cones.
These middens represent generational wealth in the squirrel world, sometimes accumulated over decades and passed down when territories change ownership.
You’ll easily spot middens in spruce forests as conspicuous mounds of brown scales surrounding the base of large trees. Red squirrels fiercely defend these territories, engaging in aggressive chases and vocal displays when intruders approach.
Pro Tip: The best time to observe red squirrel behavior is during August and September when they’re frantically harvesting and caching spruce cones for winter—you’ll witness their incredible speed as they race between trees, sometimes carrying cones larger than their own heads.
Red squirrels demonstrate remarkable ingenuity in their foraging strategies. Besides spruce cones, they consume mushrooms (which they dry by hanging in trees), bird eggs, young birds, insects, and tree sap. In some areas, you’ll find trees with distinctive bark damage where red squirrels have tapped them like maple syrup producers, returning repeatedly to feed on dried sap.
Their territorial nature means population density is relatively low compared to colonial ground squirrels, with each individual defending approximately 2-5 acres. If you’re camping or cabin-staying in Alaska’s forests, you’ll likely encounter red squirrels investigating your camp, hoping for food scraps—though feeding wildlife is never recommended.
Hoary Marmot
The hoary marmot (Marmota caligata), often grouped with ground squirrels due to their similar lifestyles, represents Alaska’s largest squirrel-family member.
These impressive rodents can weigh 15-30 pounds and stretch up to 32 inches long, making them substantially bigger than any true squirrel species in the state. You’ll recognize hoary marmots by their grizzled gray-and-white fur that appears frosted or “hoary,” black-and-white face markings, and robust, chunky build.
Hoary marmots inhabit rocky alpine and subalpine zones throughout Alaska’s mountain ranges, including the Alaska Range, Coast Mountains, and parts of the Brooks Range.
They’re colonial animals that establish territories in boulder fields, talus slopes, and rocky outcrops where complex burrow systems provide shelter from predators and harsh weather. These burrows extend deep underground, reaching depths of 20 feet with multiple chambers for sleeping, food storage, and hibernation.
Important Note: If you’re hiking in alpine terrain and hear a sharp, piercing whistle echoing off the mountainsides, you’ve likely encountered a hoary marmot sentry warning its colony of your presence—this distinctive alarm call has earned them the nickname “whistle pig.”
Like arctic ground squirrels, hoary marmots are true hibernators, entering their dens in September or October and not emerging until May or June. During their active season, you’ll observe them sunbathing on rocks—a behavior that serves both thermoregulation and social bonding purposes. They feed primarily on alpine vegetation including grasses, sedges, wildflowers, and herbaceous plants, building substantial fat reserves before winter.
If you’re exploring Alaska’s high country during summer months, watch for marmots basking near burrow entrances on sunny days, especially during morning and late afternoon hours.
They’re most active when temperatures are moderate, retreating to cool burrows during midday heat. Their rocky habitat provides excellent vantage points for watching hikers pass by, and they’ll often observe you with curiosity before diving into their burrows if you approach too closely.
These marmots play important ecological roles as prey for golden eagles, wolverines, and occasionally bears, while their digging activities influence alpine soil development and plant distribution patterns.
In some popular hiking areas like Hatcher Pass or the Kenai Mountains, you might encounter habituated marmots that tolerate human presence more readily than their wilderness counterparts.
Alaska Marmot
The Alaska marmot (Marmota broweri) holds the distinction of being endemic to northern Alaska—found nowhere else on Earth.
This specialized marmot species inhabits a narrow band of the Brooks Range, making it one of Alaska’s most geographically restricted mammals. You’ll find Alaska marmots in rocky alpine tundra habitat north of the Arctic Circle, where they’ve adapted to some of the planet’s shortest growing seasons and harshest winter conditions.
Alaska marmots closely resemble hoary marmots in appearance but tend to be slightly smaller with darker, less frosted fur and a more brownish overall coloration.
The most reliable way to distinguish them is geographic location—if you’re north of the Brooks Range divide, any marmot you encounter is likely an Alaska marmot rather than a hoary marmot.
These marmots face extreme survival challenges that few mammals can match. Their active season lasts just 3-4 months, from June through August or early September, leaving them only a brief window to reproduce, raise young, and accumulate sufficient fat reserves for an 8-9 month hibernation.
During this compressed timeline, you’ll observe them feeding intensively on tundra vegetation, often visible from a distance as they graze on sedges, grasses, and Arctic wildflowers across boulder-strewn slopes.
Key Insight: Alaska marmots hibernate longer than almost any other mammal—spending up to 75% of their lives in torpor, with body temperatures dropping to near-freezing levels for more than half the year.
Like hoary marmots, Alaska marmots are colonial and highly social, living in family groups within extensive burrow systems excavated beneath boulders and rock piles. Their sharp whistled alarm calls serve as early warning systems for the colony, alerting members to predators like grizzly bears, wolves, and golden eagles.
If you’re fortunate enough to visit their remote habitat during summer, you might observe social behaviors including play wrestling among juveniles, mutual grooming, and communal sunbathing on prominent rocks.
Due to their restricted range and remote habitat, Alaska marmots are rarely encountered except by backpackers, researchers, and adventurers exploring the northern Brooks Range.
If you’re planning expeditions in Gates of the Arctic National Park or similar northern wilderness areas, watch for their characteristic burrow entrances in rocky areas between 2,000-5,000 feet elevation, and listen for their whistles echoing across the tundra valleys.
The Alaska marmot’s limited distribution makes it particularly vulnerable to climate change impacts, as shifting vegetation patterns and snowpack timing could significantly affect their already-compressed active season and hibernation cycles.
Understanding Alaska’s Squirrel Diversity
Alaska’s five squirrel species—three true squirrels and two marmots grouped within the broader squirrel family—demonstrate nature’s remarkable ability to adapt to extreme environments.
From the tree-dwelling, nocturnal flying squirrels to the ground-dwelling hibernators that survive arctic winters, each species has carved out a unique ecological niche across Alaska’s diverse landscapes.
When you’re exploring Alaska’s wilderness, understanding these species enhances your outdoor experience and helps you read the landscape like a naturalist.
The presence of red squirrel middens indicates mature coniferous forest. Ground squirrel colonies suggest open terrain with suitable burrowing substrate. Marmot whistles reveal rocky alpine zones. Each species serves as an indicator of habitat quality and ecosystem health.
As Alaska’s climate continues changing, monitoring these squirrel populations provides valuable insights into broader environmental shifts. Warming temperatures may alter hibernation patterns, shift species ranges northward, or change the timing of critical life events like reproduction and food caching.
By recognizing and appreciating these remarkable rodents, you become part of the ongoing story of Alaska’s dynamic wilderness ecosystems.
