In 2016, a project began to retro fit a busy Rio Grande Valley highway with wildlife crossings.
The purpose was to make the roads safer for animals and motorists. But how do these tunnels function and what have researchers discovered?
CBS 4’s Dan Joseph went beneath the surface to find out.
Texas State Highway 100 is the route many take to and from South Padre Island. Traffic speeds by at 65 miles per hour and more. Below, life moves at a slower pace as migrating animals search for a safe passage.
We reached out to Octavio Saenz, Public Information Officer for the Texas Department of Transportation for more on this.
“We noticed that there were a lot of deaths–wildlife, particularly the ocelot even though there have been previous attempts to make the crossings for the ocelots we had to work very closely with the US Fish and Wildlife and Texas Parks and Wildlife to understand the innate behavior of this animal because a wildlife corridor is not just an opening in a concrete barrier,” says Saenz.
The project cost $5 million and it was completed in 2017.
Fences were also installed to keep wildlife off the road and funnel them towards the tunnels. There are an additional 10 exits in the fence line for creatures that can’t find the passageways.
Doctor Richard Kline, a professor at the University of Texas Rio Grande Valley says, “There’s actually several different sizes of these road crossings up SH 100 and the animal will just approach and if it feels comfortable it will walk through and clear a passageway to the other side.”
There are five wildlife crossings being studied by UTRGV and TxDOT for five years, and the findings are being documented by using cameras which can take pictures or record video.
According to Kevin Ryer, a research associate in the School of Earth, Environmental and Marine Sciences at UTRGV, they keep a close eye on the cameras.
“We check them every two weeks to make sure that batteries are okay and that vegetation doesn’t block the camera’s view, they record anywhere from 2,000 to 200 pictures every month of wildlife.”
The solar powered devices are mounted on both sides and some are activated when an animal crosses an invisible beam while others are triggered by infrared sensors that detect differences in temperature in movement. UTRGV researchers are currently studying a 7.1 mile portion of the highway.
“In our period of about one and a half years we’ve had 6,000 animals recorded using these five crossings— so didn’t use the road actually used the crossings and more every day and also with our cattle and wildlife guards we’ve had 3,000 animals refusing to use the road because they didn’t want to go across those cattle and wildlife guards so in total about 9,000 animals have been prevented from getting on the roads during this period of time so far”, says Kline.
“Most we see are Virginia possums, coyotes, raccoons, Eastern cottontails, white tail deer, nilgai and bobcats,” says Ryer.
Things are generally quiet during the day, but the magic happens at night.
According to Ryer, “During the summer months, when it’s really hot out, the bobcats will bring their kittens and daybed under here during the hot days, and they’ll sit in here with the kittens and just hang out and rest for the day. And then they’ll go back out at night.”
The channels beneath the highway serve several purposes– primarily they guide animals to safety but are also drainage ditches and irrigation canals–some feature catwalks where creatures like bobcats and coyotes can avoid the water, but some species are seen using them to find food.
“We’ve seen one ocelot and that ocelot it’s unclear exactly what it did. Many of the other animals we see going through these crossings have a period of learning where they have to become familiar with the crossing and most of the ocelots we have around here are transient, this isn’t the ideal habitat for ocelots that’s more up north towards Laguna Atascosa,” says Kline.
The study will continue until 2023, when the researchers will compile documents of their findings which will then be submitted to TxDOT and reported to the U.S. Fish and Wildlife Service.
But are there any conclusions that can be made at this point?
“I think these crossings have been very successful and the cooperation we have with other entities like the University of Texas Rio Grande Valley, it helps to determine at least hey–this is working and it’s helping not only the animals be safe but also the driving public,” said Saenz.
There are about 80 cameras being used to record activity at the crossings. So far, two UTRGV masters students have completed their thesis projects and graduated through this research.
According to Kline, four additional students are also working on their thesis projects, and he expects two more students will be able to work and complete their degrees on this project before it ends. All of them were fully funded through this project.
An additional five undergraduate students have been funded from this project, where they learned valuable field skills that they couldn’t get in the classroom.
Numerous other students both graduate and undergraduate have also volunteered for this project and have gained valuable experience.
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