After busy mating season, tarantulas in Southern Utah go to ground and prepare burrows for winter

Desert tarantulas are more active in the fall as males move to find female burrows during the mating season, Washington County, Utah, Nov. 2021 | Photo courtesy of Matthew Witham, St. George News

ST. GEORGE — From August to November, Southern Utah’s largest invertebrate predators, the tarantula, can be seen out and about as they look for a mate. 

Tarantula seen on Thunderbird Gardens trail, Cedar City, Utah, Nov. 3, 2020 | Photo by Paul Dail, St. George News

Falling temperatures will close the window on frequent sightings of the large arachnids. Males that successfully mated mostly die out, but the females and their hundreds of eggs will ultimately emerge again when warmer temperatures return in the spring.

Amanda Barth, native insect conservation program leader for Utah State University, told St. George News tarantulas are more misunderstood than malevolent, and they fulfill a vital role in the environment as both predator and prey.

“They kind of represent the health of the ecosystem,” Barth said. “Tarantulas are large enough that they can also eat things like small lizards, mice and other rodents, but they’re primarily eating crickets and other small insects. And you don’t want to eliminate them because you’d be affecting the whole food chain.”

According to Wild Aware Utah, while Utah is on the northern border of the tarantula’s native range, the arachnid has been located as far north as Cache County. In Southern Utah, the most commonly encountered species of tarantula is the Aphonopelma chalcodes, or Western Desert Tarantula. Like most of their kind, the spiders are nocturnal and prefer to avoid humans and other dangers.

For most of the year, the tarantulas’ night-time activity and aversion to disturbance keeps them out of sight and mind for local residents. It’s only in later months when the males are more visible as they move from their burrows to find a female partner.

Increasing development will likely bring more people into contact with tarantulas as homes and other structures are built atop tarantula habitat, Barth said.

“Tarantulas are already here. They’ve always been here, and people are moving in so that’s why people are seeing many of them,” she said. “Tarantulas really don’t pose a threat. They just look big, but they’re generally very very gentle and docile. The only harm you will face is if you’re touching one or messing with it.”

As a first response to threats, the frightened tarantula will likely try to flee or find a dark, enclosed space to hide. If provoked, it can eject urticating hairs from its abdomen, potentially spraying an unsuspecting predator or human with tiny irritating barbs that can become embedded in skin and eyes.

Only as a last resort will a tarantula bite an aggressor, Barth said, and even then their venom is comparable to a mild bee sting.

Native tarantula species come in a variety of colors and appearances, Washington County, Utah, date unspecified | Photo by Mori Kessler, St. George News

If encountered in the wild, the best thing to do is to leave a tarantula alone. If it’s encroaching on a campsite or somehow found its way into a building, they can be captured and released fairly easily with a large cup and a firm piece of paper or plastic. For those that prefer to keep their distance, gently shooing the animal towards an open door with a broom can be effective.

The important thing to remember is that these spiders are natural and practically harmless, primarily serving to balance insect populations and feed larger predators. To some, they even have endearing qualities beyond their ecological utility.

“I love spiders,” Barth said. “I have a pet tarantula, and her little feet are especially very cute – they look like paws. They are the cutest thing you’ve ever seen.”

More information about tarantulas can be found through Zion National Park and the Arizona Sonora Desert Museum.

Copyright St. George News, SaintGeorgeUtah.com LLC, 2021, all rights reserved.

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