Warm Autumn Weather Brings Out Troops of Amorous Tarantulas

CC BY 2.0. A tarantula seen at California's Mt. Diablo State Park. (Ken-ichi Ueda/Flickr)

An extended mating season is bringing California's tarantulas out in droves; here's a reminder to go easy on the gentle giants.

Not long ago I was running on a perfectly picturesque California trail when I practically tripped on a tarantula. They are huge! Especially for a city slicker like me who rarely encounters insects, let alone arachnids, larger than a housefly.

Surely my scream was heard throughout hills.

I love spiders, but my opinion of tarantulas at the time was a mix of "aww, cute puppy" and abject terror. Somewhere in the hard drive that is my brain is a file of the scene below – a sleeping (and naked, ahem) Sean Connery discovering an "eight-legged assassin" in the form of a tarantula slipped beneath his sheets, courtesy of Dr. No.

But here's the thing: The venom of a tarantula is devastating ... if you are a cricket. But for humans, it's nothing. An attacker may end up with some mild irritation from the spider's tiny barbed hairs, but that's it. No dramatic spider bites, no falling in death throes from spider venom.

And this is the message that naturalists in California are trying to get out right now. Why?


This doesn't sit well with everyone. Our Katherine, upon hearing the news, said, "I am never going to SF." For people who get the willies from one little spider, legions of tarantulas isn't going to go over very well.

Jim Carlton explains in The Wall Street Journal what's behind the spiderpalooza:

"Warm weather in the San Francisco Bay Area has extended tarantula mating season – a surprisingly public affair that has led to advisories from officials to be on the lookout for thousands of giant male spiders. The spiders aren’t dangerous to people, in fact it’s the other way around."

Indeed. Unlike that scaredy-cat James Bond, we should not be smashing spiders with shoes. We need them, and they are under threat from habitat loss and fragmentation, among other perils. Spiders do many favors for us humans; for example, one spider eats 2,000 other insects a year, insects that might otherwise be eating our food crops. “If spiders disappeared, we would face famine,” says Norman Platnick, who studies arachnids at New York’s American Museum of Natural History. “Spiders are primary controllers of insects. Without spiders, all of our crops would be consumed by those pests.”

(See more here: What if all the spiders disappeared.)

Back in the Bay Area at Mount Diablo State Park, a stone's throw from my mom's house and near where I run when visiting, the setting is a veritable hotspot for the randy male tarantulas. Carlton notes that a sign at the entrance to a trail there tells visitors: “Tarantula venom is very mild and won’t harm you – unless you’re the size of a small lizard or cricket.”

As the park's website, notes: "Hollywood and the media have made tarantulas seem monstrous, so to many people these slow-moving spiders appear ominous and threatening."

"Nothing is farther from the truth," the site adds. "They are truly one of the gentle giants of the animal world."

So if you happen to come across a tarantula on the trail – or under your sheets – fear not, don't kill them; and know that while they may look terrifying, they're doing the good work.