Look out for tarantulas along Southern Nevada trails

This time of year, while driving or hiking some of our region’s back roads, you might see a few tarantulas out and about. Whether you find them enchanting or are a complete arachnophobe, these eight-legged desert dwellers are fascinating.

While they are bigger and hairier, thus more intimidating, than all other local spiders, they are actually among the least aggressive, and their bite isn’t very dangerous to most humans.

There are about 800 tarantula species worldwide, and about 50 of those live in the American Southwest. Mature tarantulas in our region are usually one-half inch to 4 inches long, pretty small compared with a variety in Venezuela that has an 11-inch leg span.

I have seen dozens of tarantulas, and many times I’ll find them walking around within about a mile of each other. I’ve observed large numbers of them on roads and trails in Death Valley, around Lake Mead, in northwestern Arizona and even as far north as Pioche. Be aware of their presence. If you spot something on the road that looks out of place, it could be a tarantula, so be careful not to run over it.

Females often live about 30 years, but males survive only five to 10 years. One theory is the male’s drive to reproduce causes its short life expectancy. In search of females, they often wander about during the day, on roads where they might get flattened, and in full view of predators.

Once they find a female and mate, male tarantulas need to get on their way quickly, or risk becoming the female’s next meal. Females have a six-to-nine-week incubation period, and once the eggs hatch there will be about 500 to 1,000 young.

Tarantulas native to the Southwest have two methods of defense. They do bite like other spiders, but they also have specialized hairs on their abdomens that they can throw at their enemies.

If you are on the receiving end of these hairs, expect irritation resembling that caused by the stinging nettle plant. If you get the hairs in your eyes or inhale them, though, it could be more serious. A tarantula bite feels like a bee sting, and that’s usually the end of it, but some people could have a more serious allergic reaction.

Many folks realize that tarantulas are gentle souls, and some people try to show off by lifting the scary-looking spiders and letting them crawl on their hands. This can cause stress to the spider, though, and a fall from this height could cause a fatal fracture to its fragile exoskeleton.

Best advice if you come upon a tarantula: Look and admire, but leave it alone.