Cold kills 2,000 bats
Many others from colony under Waugh Bridge struggling to survive, biologist says
Add Houston’s beloved bats to the mounting casualties from last week’s winter storm.
“A lot of them probably died of dehydration or starvation,” said Diana Foss, a wildlife biologist. “A lot of the young ones probably didn’t have enough body fat stored to last the short hibernation period they needed.”
The bat colony under the bridge at Waugh Drive in Buffalo Bayou Park, a beloved staple of the city, was severely impacted by the freeze.
The full extent of the damage is still unknown, as around 2,000 of the Mexican free-tailed bats that usually emerge from under the bridge at dusk were killed by unusually frigid temperatures, estimated Foss, who is with the Texas Parks and Wildlife Department and coordinator of the Houston-area bat team.
A large number of the bats are down, said Foss, barely hanging on to life on the ground. Around 20 surviving bats were taken to a rehabilitation facility to be nursed back to good health, said Trudi Smith, director of programming for Buffalo
Officials asked park-goers and dog owners to stay away from the area for safety reasons and to allow time for cleanup Monday.
The Waugh Bridge bats most likely died in the cold because they typically don’t leave to look for food if temperatures drop below 50 degrees, said Foss.
During the winter months, around 100,000 bats remain at the bridge, said Foss, and in the summer there’s 300,000.
“That’s a good thing,” said Foss. “All those thousands of bats that were gone for the winter will come back.”
Bat colony impacts from the freeze have been reported across Texas, said Foss.
“This is a double whammy for bats in the state,” she said. “We’re having a lot of deaths in Texas associated white nose fungus.”
The Mexican free-tailed bat is susceptible to the fungus but does not die from it, added Foss.
In coming days, people may see stunned bats struggling to survive in their yards, the biologist said.
Foss recommends wearing a mask and gloves before handling the bats, putting them in a sunny spot where they can warm up, such as a tree branch, and then leaving them alone to recover.
Large numbers of the Waugh Bridge colony were also killed off in 2017 during Hurricane Harvey. The damage to the colony during the storm was far worse than that of this year’s freeze, said Foss.
The floodwaters 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 under the bridge. After the storm, Foss reported seeing around 100,000.
Many of the bats took up shelter in nearby structures, such as the America Tower, after Harvey, and it wasn’t clear if they would return. But the bats over time migrated back to their home and repopulated the bridge.
“They bounced back big time,” said Foss. “We had a lot of new babies born in the bridge, and other bats elsewhere came and joined their roost.”
The success of the state’s colonies is essential to its ecological system, as bats play a key role in seed distribution, pest consumption and pollination.
“They’re a huge value to farmers in Texas,” Foss said of the Mexican free-tailed bat. “They specialize in eating moths before they can lay eggs in cotton and corn plants.”
The loss of bats, especially many young ones, was difficult for Foss to see, but she said the death toll so far accounts for a relatively small number of the Waugh Bridge colony. The bats’ ability to return to normal after Harvey gives the biologist hope.
“It hurts my heart to see,” she said. “But they’ll be OK. They are resilient.”
For tips on how to handle injured bats, visit austinbatrefuge.org or batworld.org.