Updated: October 28, 2013 at 2:13 pm
The sun sets over a rural road south of La Junta. It is a balmy night in mid-October.
Enter the entomologist, behind the wheel of a red Ford Ranger, driving slow so he can scan the highway before him.
At times like these, Whitney Cranshaw is an especially vigilant driver.
He doesn't want to squash a tarantula by accident.
"You develop a search image for them. You just look and don't drive that fast. That's the way I drive, so I see them all the time," says Cranshaw, a professor of entomology and extension specialist at Colorado State University in Fort Collins. "If there's enough light, you can see them on the road. They're not small."
On a "good night," says Cranshaw, he might spot 20 of the creatures in a mile-long stretch of isolated highway. When he sees one, he pulls over and nabs it - for his collection or a gift.
That's right, folks, tarantulas. And if the night's warm enough and you live in southern El Paso County, they could be heading your way.
The spiders are male Oklahoma browns, the most common species of the burrow-dwelling arachnids living in the southwest U.S. and the largest spider in Colorado. Not including legs, females average a body size of about 2 inches; males are slightly smaller. During the fall breeding season, mass migrations of males set out in search of females, providing ideal sighting opportunities when they emerge from prairie camouflage to beat many feet across pavement.
"If you go out at the right time, on a warm night, you could get 20 in an area," says Cranshaw. "Pueblo West is a great spot to see tarantulas."
While El Paso County is considered too elevated and cold to be tarantula territory, the shaggy arachnids have been spotted in the southern parts of the county, which could indicate their habitat is pushing north, says Paula Cushing, curator of invertebrate zoology at the Denver Museum of Nature and Science.
"We do have tarantulas in the southeast part of the state. Used to be, they didn't come north of Pueblo. Cheyenne Mountain (State Park), they have tarantulas there," says Cushing. "As we see climate change and overall warming, you're seeing the northern movement of tarantulas to Colorado Springs. People certainly could be seeing tarantulas."
Tarantulas are solitary creatures that live in underground burrows during the day and stalk and ambush their insect prey at night. While most males die by the first frost, female tarantulas can live 20 years or more.
Tarantula migrations in the southwest may last a single day or weeks.
"This is when you might see an increased movement of tarantulas in the state parks around Colorado Springs," Cushing says. "Most spiders are nocturnal, so you won't see them unless you're driving around at night, though."
Popular as pets, tarantulas are generally shy and docile and will remain so unless provoked, when they may rear back to display fangs and, rarely, bite. They don't enter homes and their mild venom only poses a threat to insects and humans who are allergic to arthropod venom, says Cushing.
"Those fangs could certainly pierce your skin, but it would feel like a bee sting," Cushing said.
In case of an unexpected, unwanted tarantula encounter, your best response is to keep walking. Tarantulas dispatch insects and pose no inherent threat to humans, so shouldn't be killed, Cushing said.
About 20 years ago, Elizabeth Erickson found a tarantula wandering in her neighbor's yard in southeast Colorado Springs.
"It was about this time of year. A big, cinnamon-colored one," says her husband, Don Erickson, a Colorado wildlife buff who later set out to photograph every type of living creature and plant in the state. "We kept it for a week or so, but it looked like he was losing weight so we let him go."
Erickson didn't take a photo of that tarantula, and he hasn't seen one of the creatures in his neighborhood since, which is likely due to development of the nearby open space.
He's got his fingers crossed, though.
"I'd love to get a photograph of one for my collection," he says.
Contact Stephanie Earls: 636-0364