Tarantulas are found in California, a natural and often misunderstood part of the state’s diverse ecosystem. These large, hairy spiders inhabit various regions, contributing to local wildlife. While their appearance can be imposing, they generally pose little threat to humans.
California’s Native Tarantulas
California is home to several native tarantula species, primarily belonging to the Aphonopelma genus. The California Ebony Tarantula (Aphonopelma eutylenum) and the Mojave Blonde Tarantula (Aphonopelma iodius) are among the most commonly encountered. These spiders are characterized by their brown, furry appearance.
Adult tarantulas measure between 2.5 to 2.75 inches in body length, with a leg span extending up to 4.5 to 5.5 inches. Their bodies consist of two main sections: the cephalothorax, which combines the head and thorax, and the abdomen. Female tarantulas are stouter than males and can live for 20 to 25 years, while males have a shorter lifespan of 5 to 8 years.
Where Tarantulas Live and Their Habits
California tarantulas inhabit a variety of environments, including grasslands, dry forests, deserts, chaparral, and oak woodlands. They are terrestrial, spending most of their lives on the ground, often residing in burrows they dig or take over from other animals. These burrows are lined with silk webbing, which helps keep dirt out and acts as a tripwire system for detecting prey.
Tarantulas are nocturnal hunters, most active during the night. They wait near their burrows’ entrance, ambushing insects, small lizards, frogs, and mice that pass by. Their poor vision means they rely on vibrations and the silk strands around their burrows to sense potential prey or predators.
Male tarantulas search for mates from late summer through early fall, specifically from August to December. During this “mating season,” males leave their burrows and can travel significant distances in search of females. This is when they are most likely to be seen by humans, contrasting with their usual reclusive, burrow-dwelling lifestyle.
Encountering Tarantulas and Safety
Despite their intimidating size and hairy appearance, California tarantulas are docile and non-aggressive towards humans. They are more inclined to retreat or defend themselves if provoked rather than to bite. Their venom is considered mild, comparable to a bee sting, and is not medically significant for most people. Bites are rare and occur only if the spider feels threatened or is mishandled.
Tarantulas possess a defense mechanism: urticating hairs. These barbed hairs, located on their abdomen, can be flicked off towards a perceived threat. Contact can cause skin irritation, itching, and rashes, and can be particularly dangerous if they get into the eyes. If exposed, these hairs can be removed from the skin using sticky tape, and symptoms managed with topical creams.
If you encounter a tarantula, observe it from a distance. Do not provoke or attempt to handle the spider, allowing it to continue on its way undisturbed. These spiders are a natural part of California’s wildlife and are best left alone.