Despite Alaska’s frigid climate, a diverse array of spider species thrives across the state’s varied landscapes. These arachnids often go unnoticed, yet they play important roles within their ecosystems. From wilderness to urban environments, spiders in Alaska exhibit fascinating behaviors and survival mechanisms.
Common Spiders Found in Alaska
Several spider families are commonly encountered in Alaska, each with distinct features. Wolf spiders (Lycosidae) are large, robust, and fast-moving hunters often seen in various habitats, including indoors. They are typically brown and furry, with long, hairy legs, and actively pursue insects on the ground instead of spinning webs. These spiders have excellent eyesight and can range up to a few inches in length.
Orb-weavers (Araneidae) are another common group, known for constructing intricate, circular webs. These spiders vary widely in size and coloration, often displaying bright patterns. They are frequently found in gardens, forests, and around homes. Orb-weavers rely on web vibrations to detect captured prey.
Jumping spiders (Salticidae) are compact, often fuzzy, and possess exceptional vision for hunting. They are known for their curious behavior and characteristic pouncing on prey. Cellar spiders, also called “daddy longlegs” (Pholcidae), are thin-legged and commonly found in basements and crawl spaces, where they spin messy webs. Other species, such as common house spiders and funnel weavers, also live in Alaska.
How Spiders Survive Alaska’s Climate
Spiders employ various biological and behavioral adaptations to endure Alaska’s harsh, cold conditions. Many species enter a state of dormancy called diapause during winter, similar to hibernation. This slows their metabolism, conserving energy and enabling survival for extended periods without food. Diapause is triggered by dropping temperatures and decreasing daylight.
A remarkable adaptation involves producing antifreeze-like compounds, such as glycol or cryoprotectants, in their bodily fluids. These compounds prevent ice crystals from forming within their cells. Spiders can remain active down to approximately -5 degrees Celsius (23°F).
Spiders also seek out sheltered microhabitats to overwinter. They might hide in leaf litter, under rocks, within tree bark, or in building crevices, including homes. Some species lay eggs in silken sacs, which provide insulation and protection. Spiderlings may hatch and overwinter within these sacs, emerging when warmer temperatures return.
Venomous Spiders and Common Misconceptions
While nearly all spiders possess venom, few species pose a significant threat to humans. Many spider bites are often perceived as dangerous, but most cause only mild irritation like redness, itching, or swelling. Often, suspected spider bites are actually caused by other insects or skin conditions.
Highly dangerous species like black widow spiders and brown recluse spiders are not native to or established in Alaska. Black widows are found in warmer climates, and Alaska’s cold winters prevent their year-round outdoor survival. Brown recluse spiders, preferring warm, dry environments, are not established in the state.
Although these non-native species can occasionally hitchhike to Alaska via transported goods, they rarely survive. Spiders bite only when threatened, such as when accidentally trapped or provoked. Native Alaskan spiders pose minimal risk; encounters are rarely medically significant, and most bites can be treated with basic first aid.