Tarantulas are present in Arizona, with over two dozen distinct species making the state their home. These large arachnids are the biggest spiders found in Arizona and can be encountered across various parts of the landscape. Their presence is a natural part of the desert ecosystem, and while their appearance can be striking, they are generally not considered a significant threat to humans.
Common Arizona Tarantula Species
Arizona hosts approximately 30 different species of tarantulas, with several being more commonly observed. The Arizona Blonde Tarantula (Aphonopelma chalcodes) is one of the most recognized. Females typically exhibit a uniform tan coloration, while males feature black legs and a copper-colored cephalothorax with a reddish abdomen. These spiders can reach a body length of 3 to 4 inches, with a leg span extending up to 6 inches.
Another notable species is the Grand Canyon Black Tarantula (Aphonopelma marxi), which is generally dark brown to black and very hairy, sometimes displaying distinctive red or orange hairs on their bellies. Females of this species can have a body length of up to 1.4 inches, with males being smaller. The Texas Brown Tarantula (Aphonopelma hentzi), despite its name, is also common in Arizona and is characterized by its dark brown body with lighter brown patches on its head and abdomen.
Habitats and Distribution Across Arizona
Tarantulas in Arizona thrive in hot, arid conditions, preferring well-drained, dry soil. Their habitats typically include desert scrub, grasslands, and rocky areas. They establish themselves by digging burrows, which can be 1 to 2 inches in diameter, or by occupying burrows previously used by other animals. These burrows serve as protection from extreme temperatures and predators, with silk strands often lining the entrance to detect prey.
While tarantulas are widespread throughout Arizona, their concentration varies by region. The Arizona Blonde Tarantula is common in saguaro-dominated plant communities and other desert areas. The Grand Canyon Black Tarantula is typically found in higher elevations in northern Arizona, including parts of the Grand Canyon, and can inhabit mixed conifer forests and sagebrush steppes. Cooler, more mountainous regions tend to have fewer tarantulas compared to warmer desert and grassland environments.
Seasonal Activity and Behavior
Tarantulas are primarily nocturnal, remaining hidden in their burrows during the day and emerging at night to hunt. Their diet consists mainly of insects like grasshoppers, crickets, and cockroaches, but they may also prey on small lizards and other small animals. The most noticeable period of tarantula activity in Arizona occurs from late summer through early fall, typically from August to October. This increased visibility is largely due to male tarantulas leaving their burrows in search of mates.
During this mating season, male tarantulas, often between 8 to 10 years of age, embark on extensive journeys to find females. After mating, male tarantulas typically have a short lifespan, often dying within a few months. Female tarantulas, however, can live much longer, with some species surviving for 20 to 25 years or even up to 35 years.
Encountering Tarantulas Safely
Tarantulas are generally docile and not aggressive towards humans. They prefer to avoid confrontation and will typically attempt to flee if disturbed. If threatened, a tarantula may rear up or flick urticating hairs from its abdomen, which can cause skin irritation, itching, and redness. These barbed hairs can also cause irritation if they get into the eyes, requiring careful removal.
A tarantula bite is rare and usually occurs only if the spider feels trapped or is provoked. The venom of North American tarantulas is considered mild, often compared to a bee sting, causing localized pain, swelling, and redness. Serious health effects or allergic reactions are uncommon. If a tarantula is found indoors, it can be gently encouraged into a container, such as a dustpan or cardboard box, and safely released outside. Maintaining a respectful distance and observing them from afar is the best approach to coexisting with these fascinating arachnids.