Pelicans Are Dying Along A South Texas Highway, But There May Be A Fix

There’s a stretch of state Highway 48 near Brownsville that’s in need of an upgrade – not because of potholes or congestion, but because of the birds.

By Michael MarksOctober 3, 2018 9:27 am| ,

The problem happens near the Gayman Bridge, which is part of state Highway 48. The bridge separates the bay where the pelicans live from the Gulf of Mexico, where they hunt fish. On some winter evenings, north winds topping 30 miles per hour make it hard for the pelicans to fly over the bridge; some are forced down onto the highway.

“So, two things were happening: they were being run over by motorists, and they become a hazard for the drivers,” says Texas Department of Transportation spokesman Octavio Saenz.

The pelicans haven’t caused any automobile accidents so far, but it’s not just the wind that’s at fault here; it’s also the bridge itself. On either side of it, there are solid, waist-high concrete barriers designed to prevent cars from running off the road. But Saenz says that when the wind hits those barriers, it creates a kind of vortex that can trap the pelicans if they’re flying low enough.

“We found that there was a zone of downdrafts, that air that presses the birds down to the ground,” Saenz says. “And the issue is that once that bird is grounded, because there’s a swirling airflow in that area, it kinda prevents the birds from taking off.”

He knows this because TxDOT’s been studying the wind mechanics at the bridge for over a year in order to mitigate a dangerous situation.

In audio recorded during a cold front last year, you can hear the strong wind. In the video from TxDOT, below, you can see that it’s sometimes hazy, the road might be wet, and the speed limit is 75 miles per hour.

Despite that, for the past two winters a team of volunteers has stood along the highway during cold fronts to slow down cars and carry downed pelicans across the road to the bay where they roost. They’ve saved over 270 pelicans that way, and in the process have helped keep the problem on TxDOT’s radar, according to Nicole Ekstrom, board president of the Friends of Laguna Atascosa National Wildlife Refuge, a local environmental group.

“The public has been very in support of this, and that team going out there regularly has not allowed it to come out of the spotlight,” Ekstrom says.

But as successful as they’ve been, the pelican team treats the symptom of the problem, not the cause. That’s why TxDOT has developed a plan to swap out the solid barriers for a design that won’t create as strong of a downdraft. It used data collected from the bridge and the wind- tunnel tests to figure out what kind of barrier would most reduce the vortex; that turned out be a design with large slits to let air pass through it.

“It’s going to look more like a concrete railing,” Saenz says. It still provides safety, but it doesn’t mess with the flow of the air that had caused this downward swirl that sorta traps the pelican in that area.”

There will still be some downdrafts during strong winds, but they shouldn’t be as extreme. The change feels like a win for folks like Ekstrom.

“You know, I mean I think at the beginning nobody thought that it would ever be taken this seriously,” Ekstrom says. “It was just a group of people going out there and grabbing them off the road, you know. And everybody’s really happy that they’re going to do something.”

Saenz say that the next step is finding money for the project in TxDOT’s budget. Right now it’s unclear how much that will cost, but Saenz is confident it will get done.

“Because it’s something that’s important to the community, it’s important to our local leaders,” Saenz says. “This is something that needs to be done because annually, it happens again and again and again.”

And the plan is to get it done fairly soon. Although the pelican team will still be needed for the next few months, the goal is to have the new barriers in place by winter 2019.