'They move en masse at this time of the year': Colorado researchers look for ways to manage tarantula migration and traffic

Highway overpasses have been successful tools to help mitigate animal-vehicle collisions, now researchers are exploring how underpasses can do the same for Colorado's smaller creatures.

"We've got a really cool project that we are looking into which is working with CDOT on exploring whether or not we can provide underpasses under the freeways down there so that the tarantulas can go under the highways instead of getting squished when they're out looking for mates," said Richard Reading, the VP of Science and Conservation, at Butterfly Pavilion.

Reading, who has a Ph.D. in wildlife ecology, has been with Butterfly Pavilion for the last 6 years and has recently been looking into why populations of Colorado's tarantulas are substantial in some areas, and not in others.

"They move en masse at this time of the year so from late August to early October primarily, the males are out looking for females so we call it the mate-gration, because it's not a true migration."

In some areas, Reading says there have been as many as 70 tarantulas per acre documented but for those populations burrowing along the side of the highway, they have to make it through traffic before they find a mate. Every year during the great mate-gration, hundreds of males are squished before they can complete the journey.

"So what we wanna do, is avoid tarantulas from getting squished and other little things, so if we produce a lot of culverts or underpasses, things like tarantulas, box turtles, other reptiles and amphibians can use those culverts as well as other insects and not get squished," said Reading.

Reading has suggested building drift fences leading into the culverts or underpasses- but that's still a long way out. Colorado Department of Transportation (CDOT) has yet to commit to the projects but says it's open to continuing discussions on the feasibility. That's what Reading is currently working on; figuring out if this idea will be a worthwhile endeavor is the next step.

"We're ready to get going with a pilot study, so we're working with CDOT on an initial pilot study to see if we can track the best places to put these culverts by putting in remote cameras, sensory cameras that will turn on when there is movement and then get pictures on the road where the tarantulas cross; so, we'll put a bunch of cameras along the road and we'll also look at burrow densities of tarantulas along the side of the road and then we'll also look at where they mostly have been squished, he continued, "

Reading hopes to have the study up and running before the end of the year.

The peak time to view the mate-gration is mid-September near Comanche National Grassland south of La Junta off U.S. Highway 109.

If you aren't able to catch the tarantulas in their natural habitat, you can see them up close at "Spiders Around the World", an event running Oct. 7 through Oct. 31 at the Butterfly Pavilion.