CLAYTON -- When 8-year-old Kai Welsh spotted a tarantula crawling across a Mount Diablo trail, he didn't freeze, flee or attack the giant hairy spider that frightens many people.
Under the supervision of adult nature hike leaders, the Walnut Creek boy let the male spider crawl over his hand, and continue its autumn journey to find a mate.
"He's not scary," Kai told other youngsters clustered around him last week in Mt. Diablo State Park's Mitchell Canyon. "He's very light. Some people find them scary, but he's not as scary as he looks."
Male tarantulas are leaving their burrows and crawling around in large numbers on Mount Diablo and many other places in the East Bay and South Bay this time of year in an autumn ritual to find mates before dying.
The spider's appearance scares some people. It has been characterized in fearsome images since the first federal surveyors wrote in the 1860s about giant spiders on Mount Diablo that were as big as birds and had fangs as big as those of rattlesnakes.
Naturalists, however, say the slow-moving tarantulas are docile, defensive and fragile.
You might call them wimps.
The big spiders would rather flee than fight. If confronted, they rear up and flick off sneeze-inducing hairs -- a material that once was harvested to make sneezing dust sold in old joke and gag stores.
If a tarantula bites a human harasser, the bite is less painful than a bee sting, spider experts say.
"Many people are scared of all spiders even though there are only one or two around here that are poisonous," said Gary Meneghin, a retired biologist and volunteer with the Mount Diablo Interpretive Society, a natural education group that leads "tarantula treks" on Mount Diablo. "The movie industry has made the tarantula out to be ferocious. Our modern culture has not embraced them, although in some Native American cultures, the tarantula is linked to the early creation stories."
Tarantulas spend most of their lives in underground burrows, and pop out to grab a meal when a beetle, cricket or other insect wanders by.
Unable to see well or move fast, the male tarantulas leave their burrow homes for good when they are seven to 10 years old. Then they mate and die.
These daring autumn crawls make the usually nocturnal creatures visible in places such as Mount Diablo, Sunol Regional Park, Black Diamond Preserve near Antioch, and Henry Coe State Park near Morgan Hill. Coe Park held a tarantula festival Saturday to celebrate the autumn ritual.
"It's not really a migration. It's a ramble," said Ken Lavin, a naturalist who led the interpretive society's hike on Mount Diablo last week. "It's their last mission, and then they're gone."
When the male finds a female's burrow, it taps on the ground -- mimicking the motion of insect prey -- to draw her out.
To avoid being eaten during mating, the male uses leg hooks to neutralize the female's fangs.
After the encounter, the male has a short life of weeks, days or even hours. He may starve, get eaten by birds or coyotes, freeze, or wither away if it's hot.
On the tarantula trek Wednesday during a heat wave, nature hikers discovered one tarantula in the middle of a trail after it apparently had died hours before in temperatures near 100 degrees.
"It's a tough life for a male tarantula," Lavin said.
The hikers came across three tarantulas before 6 p.m., and six more crawling around later during cooler temperatures. Prime tarantula viewing hours are two hours after sunrise and two hours before sunset.
Tarantula hike leaders have seen an average of about 15 tarantulas per trip this season.
"It's a good year for tarantulas," Lavin said. He attributes the abundance in part to favorable environmental conditions seven years ago when the parents of this year's males mated.
"I also think the cool, wet weather this year has helped," he said. "It's produced a lot of insects for the tarantulas to eat."
Staff writer Randy Myers contributed to this story.
Tarantulas are shy creatures with a bite no worse than a bee sting, but their fearsome appearance makes them a convenient Hollywood villain. Some notable movies with tarantulas:
Source: The Internet Movie Database
IF YOU GO
Tarantula treks are planned from 5-7 p.m. Wednesday, Saturday and Sunday starting at the Mitchell Canyon Visitor Center at Mt. Diablo State Park. Go to www.mdia.org and click on "bulletin board" for details.