For Texas wildlife lovers, it’s been one of this century’s most electrifying developments. Black bears had been hunted out of Texas by 1960. But in recent decades, from remote redoubts in Mexico, these powerful creatures have been returning to the state.
How will the Trump administration’s new border-infrastructure projects impact these bears? Scientists at Alpine’s Borderlands Research Institute, or BRI, are seeking answers to this timely question.
Bears first returned to Big Bend National Park in the late 80s. They’ve since expanded across the Trans-Pecos, into the Hill Country and south as far as the Eagle Pass area.
BRI researchers have used GPS collars to track dozens of Texas bears. But in 2023, a bear collared on the Devils River undertook a particularly remarkable odyssey.
Caitlin Camp Pappas is a PhD researcher with the BRI and Texas A&M University Kingsville.
“We saw his movements,” Pappas said, “and he was from like Devils River State Natural Area to 60 miles south to the Burro Mountains in Mexico. And then he made this trip back. They're making these incredible movements.”
The bear’s repeated journeys, Pappas said, were a reminder: For wildlife, this isn’t a binational setting, but a single landscape. Bears aren’t simply dispersing from Mexico into Texas; they’re using resources on both sides of the Rio Grande.
The BRI launched the Transboundary Black Bear Project to better understand these movements, and how border barriers might impact them.
“I think that's what's really interesting is, initially, before all this research started, we had an idea that they're coming from Mexico,” Pappas said, “but we didn’t know how much they use the landscape in Texas as well as going back and forth.”
Initially, Pappas’s research focused on Val Verde, Kinney and Maverick counties – where 30-foot-high border walls are already in place, and where gaps in those walls are currently being closed. But she detected few bears there, and she’s expanded her work to include the Trans-Pecos.
BRI researchers use traps – often baited with donuts – to capture bears. When a trap springs, they arrive quickly to anesthetize the bear, take blood and other samples and attach a tracking collar. Pappas and her colleagues will be trapping bears across the region in the coming weeks.
Pappas said that the traffic and activity associated with border-project construction is likely to impact bear movements. Bears obviously can’t scale a 30-foot wall. A continuous vehicle barrier – like the one planned for 165 miles of Val Verde, Terrell and Brewster counties – might turn a bear back or stress the animal.
The Rio Grande itself is an important resource for bears; barriers could limit the animals’ access to food and water. And destruction of riverside vegetation will remove habitat that researchers know bears use for winter dens.
Pappas and Mexican collaborators are collecting DNA samples from bears on both sides of the river, to understand genetic relationships. Hindering the movement of bears would also hinder the flow of genes, Pappas said.
“But then long-term, having those isolated populations and less genetic diversity – that’s potential inbreeding,” she said. “So I think if they're not allowed to move back and forth, it could impact them.”
In her research, Pappas may identify corridors that are particularly important for bears. Perhaps modifications could be made to border barriers to allow bears to continuing using these corridors.
Bears can make trouble, but many Texans have celebrated their return. The raw, undeveloped character of the West Texas borderlands is at the center of that story. Changing the region’s wilderness character could throw the future of bears in Texas into question.
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