A hairy leg reaches over the edge of the rock, following the vibrating silk to the unwary beetle basking in the moonlight. The rest of the tarantula follows, grasping its prey and injecting the paralyzing venom. While there are more than 850 tarantula species worldwide, only 18 species are known to inhabit California's grassy hillsides, foothills and deserts.
All of California's tarantulas are members of Aphonopelma, which are ground-dwelling hunting spiders. The California tarantula is nocturnal for most of its life, leaving its hole at night to hunt for beetles, grasshoppers, lizards, mice, scorpions, spiders and other insects. Male tarantulas require 7 to 10 years to mature before emerging to roam the area, looking for females. While the male tarantula only lives a few months after it reaches maturity, females may live up to 25 years.
The California ebony tarantula (Aphonopelma eutylenum) and the Bay Area blond tarantula (Aphonopelma smithi) live in the grassy, rolling hills of the East Bay, including Alameda County. The California ebony tarantula's range extends south to San Diego. Solitary spiders, tarantulas live in holes in the ground, or occasionally amid rocks, on dry, well-drained grass-covered hillsides or oak-filled woodlands. Tarantulas have poor vision, so they depend on the silk that covers the ground in and around their burrows to send a vibration, signaling that prey is within their reach.
The Sierra Nevada Foothills
The steep, rocky hillsides of the Sierra Nevada foothills, covered with trees, brush and poison oak, harbor thousands of hairy California ebony tarantulas. In fact, there are so many tarantulas crawling out of their burrows in mid-October that the tiny town of Coarsegold, the gateway to Yosemite, celebrates tarantulas with a festival. Feeding on baby rattlesnakes, insects, lizards and scorpions, the tarantulas thrive in the mountainous foothills, despite the winter snows and hot summer days.
Living in the deserts of southern California, Arizona and New Mexico, the desert blond tarantula (Aphonopelma chalcodes) hides in burrows during the day. While the desert climate is one of extremes, up to 120 degrees Fahrenheit in the summer and below zero in the winter, desert tarantulas require little water, obtaining moisture from their prey. Desert tarantulas hunt at night, preying on insects, lizards, mice and other spiders. In the fall, after heavy rains, mature males emerge from their burrows seeking females. While some males are eaten after mating, those who survive have a short lifespan, living only two or three months after reaching maturity.
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