Alaska’s vast wilderness and extreme climate support diverse wildlife adapted to cold conditions.
The Absence of Native Snakes
Alaska definitively has no native snake species. The state’s climate is too harsh for any known snake species to establish a permanent, breeding population. While there have been rare reports of snake sightings, these are typically attributed to escaped pets or transient individuals that may have arrived via cargo. Occasional common garter snakes might be spotted in the extreme southeast due to proximity to British Columbia, but they do not form established groups.
Environmental Factors Limiting Snake Presence
Snakes are ectothermic, or cold-blooded, relying on external sources like sunlight and warm surfaces to regulate body temperature. Alaska’s extreme climate, with long, frigid winters, is too cold for snakes to maintain the necessary body heat for survival.
Permafrost across much of Alaska poses a significant barrier. This ground, frozen year-round, prevents access to sufficiently deep, unfrozen areas for snakes to safely overwinter. Even if shelter were found, prolonged extreme cold would likely lead to their demise.
Short summers further compound the challenge. While some areas of Alaska can reach up to 90 degrees Fahrenheit in summer, these warm periods are often too brief for snakes to adequately warm their bodies, hunt, digest food, reproduce, and grow enough to survive the subsequent long winter. The limited daylight hours during much of the year also restrict opportunities for basking and thermoregulation, which are vital for a snake’s metabolic functions. Consequently, the lack of suitable microhabitats with consistent sun exposure and rocky outcrops necessary for proper thermoregulation and denning severely restricts their potential presence.
Distinguishing from Other Cold-Blooded Animals
Despite the absence of native snakes, Alaska is home to other cold-blooded animals, specifically certain amphibians, that have evolved remarkable adaptations to survive the cold. The wood frog (Lithobates sylvaticus) is a prime example, found across much of Alaska, even north of the Arctic Circle. These frogs can tolerate their bodies freezing solid during winter, surviving for months with no detectable vital signs like heartbeat or breathing. They achieve this by producing cryoprotectants, such as glucose and urea, which act as a natural antifreeze, preventing lethal ice crystal formation within their cells.
Another cold-blooded resident is the rough-skinned newt (Taricha granulosa), primarily found in Southeast Alaska. While not freeze-tolerant to the same extent as wood frogs, these newts also employ strategies to cope with cold, such as seeking shelter in moist terrestrial habitats or aquatic environments during winter. Their presence, along with other salamanders and frogs, demonstrates that some ectotherms can persist in Alaska through specialized adaptations.
People sometimes mistake other elongated creatures for snakes. For instance, eels, which are fish, are often confused with snakes due to their serpentine shape. However, eels possess gills and often fins, and lack the scales characteristic of snakes. Similarly, legless lizards, though not found in Alaska, are another group that can be mistaken for snakes; these lizards, unlike snakes, have eyelids and external ear openings.