Colorado tarantulas on parade

By Gary Raham
Nature Writer and Illustrator

Perhaps you've missed Colorado's annual parade of tarantulas. Perhaps you didn't even know, or care to know, that Colorado can claim parading tarantulas on its list of attractions.

It helps if you live in southeastern Colorado somewhere near Pueblo, Cañon City or La Junta--or if you choose to lurk on southeastern Colorado's grasslands in the fall looking for dinosaur tracks, shark's teeth, ammonites and other fossils.

For several years I've had to plead guilty to the latter obsession. Last September, while assembled with other paleontologists in a parking area in the Comanche National Grasslands south of La Junta, a male tarantula stepped into our circle of attention looking for a mate. Alas, all he found were admirers of his stately grace and ancient Paleozoic lineage.

We took pictures and annoyed him enough that he reared back on his hind legs to display his fangs. Although tarantula fangs can pierce the skin effectively and inject venom, that venom has never been known to kill or even cause serious symptoms in humans.

Such is not the case for a tarantula's normal prey, such as other wandering arthropods and even young rodents huddled in their burrows. Most tarantulas dig tunnels to hide and rest in, or they appropriate abandoned tunnels of other wildlife. Eating current residents before taking possession may certainly be an option.

We allowed the wandering male to pursue his amorous quest in peace, knowing that he only had a matter of weeks to hook up with a female before he died. As fearsome as he might look, he had enemies of his own--most notably a wasp dubbed the tarantula hawk that would like to paralyze and lay eggs on him so that her young will have fresh food when they hatch. (You may recognize a plot line quite similar to that of "Alien.") He also had to mate with discretion, as even a female of his own species might consider him as a nutritious, post-nuptial meal.

Few people, it seems, have taken the time to get to know Colorado tarantulas well. Ralph Vary Chamberlain (1879-1967), a Utah zoologist who taught at Brigham Young University and the University of Utah, discovered our resident tarantula, which now goes by the scientific name Aphonopelma coloradanum. He named 77 genera and 1,001 species during his long career, and he formally described Colorado's tarantula in 1940.

Walker Van Riper, a professor at University of Colorado for many years, wrote a book on common Colorado spiders in 1950 and included some notes on tarantulas. "This species does not dig its own burrow, as some do, but lives in abandoned rodent holes and hollows under logs and stones." He also said that both sexes might be found wandering during mating season. They become conspicuous on highways as large, furry, creeping travelers, far too slow to avoid primates in speeding Toyotas.

During two years of hunting fossils in late September, I came across perhaps a dozen wandering tarantulas. Their dark brown legs looked sleek and their bodies resembled tan suede. Taking slow deliberate steps, they seemed to be creatures from another time, traveling--and somehow surviving--among much quicker and newer model animals. Barry Noreen, a reporter for The Colorado Springs Gazette, said in a 2001 article that some male tarantulas were fitted with miniature radio transmitters. They moved about a mile in 18 days or .0023 miles per hour.

Some people make pets of tarantulas, as I described in a September 2006 article in the North Forty News. In captivity, they are more ornamental than good companion material. Female tarantulas, the choice for pets because they can live for 20 years or more rather than a male's handful of months, tend to be nest potatoes most of the time.

For me, tarantulas are best seen on parade, during the low angled light of dawn or late afternoon. Then they cast twisted, eight-legged shadows on rocky landscapes and, for a moment at least, the contemplative observer gets a brief glimpse of a venerable era on Earth and one of the amazing creatures that made it so.