Alaska stands as a unique outlier among U.S. states, notably lacking any native snake populations. The state’s environment is largely unsuitable for them. Alaska’s climate and terrain present significant challenges that prevent snakes from establishing and sustaining wild populations.
Why Alaska Lacks Native Snakes
Alaska lacks native snakes primarily due to its harsh climate. Snakes are ectothermic, relying on external heat sources to regulate body temperature. Alaska’s long, frigid winters and short, cool summers do not provide the consistent warmth necessary for snakes to function, hunt, digest food, or reproduce effectively. Below certain temperature thresholds, around 39 degrees Fahrenheit, most snakes are physically unable to move.
Even brumation, a state of dormancy similar to hibernation, is insufficient for snakes to survive Alaska’s extreme cold. While snakes can slow their metabolism during brumation, they still require a certain amount of warmth to maintain vital bodily functions. The ground often freezes solid in Alaska, making it difficult for snakes to find or create suitable hibernation sites, known as hibernacula, for insulation from sub-freezing temperatures.
Beyond temperature, suitable habitat and prey availability also contribute to the absence of snakes. Permafrost, or permanently frozen ground, covers much of Alaska, limiting the deep, unfrozen burrows that snakes might use for shelter. The harsh climate restricts the diversity and abundance of prey animals that form a snake’s diet, making food sources scarce or seasonally unavailable.
Non-Native Snakes in Alaska
Although Alaska has no established native snake populations, non-native snakes have rarely appeared in the state. These occurrences are almost exclusively linked to human activity, primarily through the pet trade. Escaped or intentionally released pet snakes account for most sightings of non-native species.
Such incidents are isolated, and these non-native snakes are unlikely to survive long-term in the Alaskan wilderness. The same environmental factors that preclude native snake populations, such as the extreme cold and lack of suitable habitat, quickly lead to their demise. For example, a 17-foot Burmese python that went missing in 2017 eventually returned to its owner after two weeks, highlighting the difficulty for such animals to thrive independently.
Accidental transport is another rare possibility for non-native snakes reaching Alaska. Snakes can sometimes hitchhike on cargo or vehicles arriving from warmer regions. However, these are sporadic events, and any snakes arriving this way are unable to establish wild breeding populations due to the inhospitable conditions.
Animals Often Mistaken for Snakes in Alaska
Given the absence of native snakes, sightings of snake-like creatures in Alaska often turn out to be other animals. Legless lizards, which exist globally and resemble snakes, are not native to Alaska. These lizards can be distinguished from true snakes by features such as eyelids and external ear openings, which snakes lack.
Certain fish species, particularly lampreys and some eels, are frequently mistaken for snakes due to their elongated, cylindrical bodies. Lampreys, which are native to Alaska, are jawless fish with a snake-like appearance, sometimes colloquially referred to as “eels.” While true eels are present in Alaskan marine waters, they are distinct from snakes and possess fins, unlike snakes.
Some terrestrial invertebrates can also be confused with small snakes. Large earthworms or certain insect larvae, such as those of the fungus gnat species Sciara serpens, have been mistaken for snakes. These larvae form large, collective masses that move in a coordinated, snake-like column, leading to their common designation as “snake worms.”