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Waugh Street Bridge

The freeze was hard on the bats

Dammit.

The bat colony under the bridge at Waugh Drive in Buffalo Bayou Park, a beloved staple of the city, was severely impacted by last week’s winter storm.

While the full extent of the damage is still unknown, many of the Mexican free-tailed bats that usually emerge from under the bridge at dusk were killed by unusually frigid temperatures, according to Buffalo Bayou Park officials.

A small number of surviving bats were taken to a rehabilitation facility to be nursed back to good health, said Trudi Smith, director of programming for Buffalo Bayou Partnership. Officials asked park-goers and dog-owners to stay away from the area for safety reasons and to allow time for clean-up on Monday.

Diana Foss, a wildlife biologist with the Texas Parks and Wildlife Department and coordinator of the Houston area bat team, examined the colony Monday and was still making assessments of the loss by evening.

[…]

The Waugh Bridge colony was also killed off in droves during Hurricane Harvey in 2017. The flood waters submerged the Waugh overpass and the bats couldn’t fly out, drowning many. Residents saved some of them, but tens of thousands were displaced or died during the storm. Before Harvey, there were around 300,000 living in the bridge. After the storm Foss reported seeing around 100,000.

Many of the bats took up shelter in nearby structures, like the America Tower, after Harvey and it wasn’t clear if they would return. But the bats migrated back to their home and repopulated the bridge over time.

See here for the background. This is a small thing, obviously, much less important than the human misery that the freeze brought. We can still feel bummed about the bats without losing sight of the bigger picture.

The Harvey effect on the Waugh Street Bridge bat colony

It was bad, but we hope they will recover.

Tens of thousands of bats perished or were displaced from their home at the Waugh Bat Colony when Hurricane Harvey swept through the city this summer, according to bat experts.

“Pre-Harvey, we had at least 300,000 bats in the bridge,” said Diana Foss, a wildlife biologist with the Texas Parks and Wildlife Department, and coordinator of the Houston area bat team.

“But watching the emergence at Waugh right now is kind of depressingly lower than that,” she continued, describing the daily flood of bats from beneath the bridge at Allen Parkway and Waugh Drive, during which bats emerge en masse at twilight to hunt for food. “What I’m seeing is, about half the bats are emerging.”

When the hurricane dropped more than 50 inches of rain on the city, the bayou’s water downtown surged to record levels. For the first time since the bats took up residence in the cracks beneath the Waugh overpass, the elevated highway was submerged. Bats lacked the 15 feet of clearance they need to drop down from their roosts and take to the sky. Their plight didn’t go unnoticed. Residents tried to save the bats, hanging off the bridge and scooping them from the water as they rushed by. But it wasn’t a perfect science.

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In the days and weeks after the storm, residents noticed a new pattern in the sky during the bats’ evening emergence: In addition to a swarm of winged mammals flying out from beneath the bridge, smaller populations exit from nearby buildings. They join up with the bats from the bridge during their hunt, then return to their new homes for the night, before repeating the same cycle the next day.

Whether these displaced bats will return to their former home under the bridge isn’t yet known, said Cullen Geiselman, a member of the local bat team, who earned her doctorate studying bats.

“I guess they could have moved on,” she said. “We’ve played with some ideas and haven’t gotten very far.”

Houstonia wrote about this in the immediate aftermath. As noted, some number of bats managed to move to other dens, and some others have returned to Waugh. The overall population is definitely smaller, and bats don’t have high reproduction rates, but the hope is that over time the colony under the bridge will get back to its previous side. I’m rooting for them.