California Tarantulas Caught in Web of Lies
October 26, 2011
Nathan Graveline, DFG Biologist, (209) 588-1780
Carol Singleton, DFG Communications, 916-322-8962
With Halloween just around the corner, it’s time to crush the myths surrounding one of the season’s most misunderstood critters – the tarantula. These hefty, hairy spiders have been unjustly maligned for decades and Department of Fish and Game (DFG) wildlife biologist Nathan Graveline wants to set the record straight.
Graveline has been fascinated with tarantulas since he was a young boy growing up in the Central Valley, where these spiders enjoy the dry, well-drained soil.
“I handled quite a few tarantulas and was never bitten, but I did get a rash from the small irritating hairs on their backs,” said Graveline.
Despite never being bitten, Graveline does not recommend handling these shy arachnids. Although a tarantula’s venom is not lethal, the bite may be painful, similar to a bee sting, due to the size of the spider’s fangs.
“It may be tempting for some to try and handle tarantulas given their docile nature, but while the chance of receiving a bite is small, there is a good possibility of injuring the spider,” he warned.
Graveline has passed his love of tarantulas on to his three-year-old daughter. Living in the Sierra foothills of Sonora, they occasionally see the creatures emerge from their dens and creep across the landscape. This summer he and his daughter discovered a burrow near their mailbox. At night they would deposit crickets at the spider’s doorstop then watch it come out to feed. In addition to crickets, the tarantula enjoys beetles, sow bugs and other small insects. The spider’s venom reduces the prey to a soft mush, which can be easily slurped up and digested.
The tarantula, unlike the stereotype depicted in Halloween decorations, is a ground dweller. It is too heavy to hang from a web in the rafters, and it does not sit in a web waiting for prey or unsuspecting human victims. Instead, it uses silk to line its burrow and cover the opening, and to aid in the mating process.
During mating season, between September and October, the mature male tarantula at approximately 7 years of age will leave his burrow in search of a female. In preparation for this quest, he will spin a sperm web, deposit his sperm into it and collect some on his pedipalps – the small leg-like appendages near the mouth – to carry with him. When he finds an ideal mate, the male deposits his sperm into the female using his pedipalps.
“If the male doesn’t leave quickly, he may become the female’s next meal,” Graveline explained.
After mating is complete, the female returns to her den and spins a bed of silk, on which she deposits the fertilized eggs. Then she lays down another layer to create a billowy cocoon for her offspring, who will emerge in six to seven weeks. The baby tarantulas stay in their mother’s den for about a week before they venture out into the world and seek burrows of their own.
These young spiders are particularly vulnerable to predators such as lizards, snakes, birds and the fearsome tarantula hawk. If she’s careful, the female tarantula can live as long as 20-25 years. The male is not so fortunate, for he will die a few months after mating, if he is not consumed in the process.
So, as you hang your Halloween decorations this fall, remember that, like the docile, much-maligned tarantula, not everything is what is seems.