Mud, moss, bark, leaves, and other forest materials cover the towers made by California turret spiders, camouflaging these unusual lairs. Inside, the towers are lined with white silk and can extend six inches down into the ground. The ambush hunters, who stay hidden in their burrows, have poor eyesight and use vibrations to identify potential meals. See how they jump out of their tiny towers to catch (or miss) prey in this episode of Deep Look.
Turret spiders are found only in California, and only in moist woodlands, and nearly always on north-facing slopes. Look for them on hillsides along trails, on stream banks, or along road cuts, where their burrows (turrets) can be so dense that 15 might be found in an area the size of this page.
Leonard Vincent, a professor at Fullerton College who studied a population of turret spiders for two years, notes that an insect falling on the ground amid these burrows would find itself “in a minefield” because the spiders lurk just inside the entrances of their burrows, rushing out with incredible speed and venomous fangs when they feel the vibrations of approaching prey. But competition for food probably means that many spiders go months without a meal.
Vincent discovered that turret spiders end up in such dense congregations because they are highly susceptible to dehydration, so young spiderlings build burrows immediately around their mother’s burrow. The alternative is roaming in search of new homes and likely dying if they’re forced to cross an opening in the forest. Once settled in their new burrows, females are thought to live 16 years, and they never wander nor even leave their burrows. Males only leave their burrows once, in August or September of their eight or ninth year, when each one makes a heroic effort to find a female and mate before he dies.
Watch more spider survival tactics: Sicarius spiders self-bury in the sand, a “snail shell spider” who uses its web to hoist objects, Darwin’s bark spiders construct giant nets, and a species of cartwheeling spider.