AUSTIN (KXAN) — Hundreds of thousands of bats may have frozen to death during the historic winter storms that hit Central Texas in February.

That’s the estimate from the Austin Bat Refuge, who described the mental toll of discovering hundreds of dead or dying bats night after night during the bad weather.

“It was tough,” said Lee Mackenzie, who runs the refuge with his wife Dianne Odegard. “It was more loss than we’ve seen in over a decade of doing this work all in one week.”

Despite the significant losses, the long-term impact on Austin’s famous bat population may be limited, Odegard and Mackenzie explained.

Austin Bat Refuge shows off a rescue bat Feb. 29, 2020 (KXAN Photo/Kate Winkle)

That’s because many of the Mexican free-tailed bats that roost around the city, most notably under the Congress Avenue Bridge downtown, may not have returned from their winter migration to Mexico before the freeze.

Instead, bats that migrate south to Central Texas from states such as Oklahoma and Kansas likely make up most of the winter storm deaths, the refuge owners explained.

“We suspect that perhaps it was that population that suffered the most from the freeze, that they may notice a decline in bat numbers up to the northern part of the range,” Mackenzie said.

“We didn’t see evidence of big migrations coming back in before the freeze,” he added. “So we think that our local bat population may not have been affected as much as we had feared.”

The mental toll of the winter storm

The couple admitted that the days and weeks after the storm were “pretty intense and pretty sad” as they came to terms with the loss of life and attempted to help the remaining bats.

“We’d go to four or five different bridges every night and collect 100 dead and dying bats,” Mackenzie said.

Overall, they recovered about 4,000 bats. While most of them were dead by the time they arrived at the refuge, the couple released about 600 back into the wild, and still have a few remaining from February that are trying to recover.

Austin Bat Refuge shows off a rescue bat Feb. 29, 2020 (KXAN Photo/Kate Winkle)

“These bats were basically frozen solid in the roost so it’s remarkable that any survived at all,” Mackenzie added.

Odegard said that at first, they were too busy feeding and rehydrating the bats trying to survive to think about what they were dealing with, as well as what was happening to people in the community.

“By the time most of the work was winding down, we got a chance to think about it and do a little bit of grieving for the ones that we lost,” she said.

“Every one of them is hard to take,” Mackenzie added. “Many thousands in a week is totally devastating.”

With the historic bad weather in the rearview mirror, there is a glimmer of hope for the refuge – baby season starts in about a month.

Look after your palm trees, people

A couple of years ago, the refuge recorded its first ever report of southern yellow bats in Austin.

During the storm and thaw, they received multiple calls about the species, which they said may indicate an expansion in the local area.

However, that expansion could be affected by another problem caused by the winter storm – the impact on palm trees in and around Austin.

Southern yellow bats only roost in palm trees – so Austin Bat Refuge is urging people to “give their palm trees a break” until the fall to help the species, particularly as their mating season is coming up.

“A lot of them (palm trees) are just now showing new growth and we’re hoping that people won’t cut them down or cut all the dead fronds off,” Mackenzie said. “We would hope people would give them a chance – that brown skirt is a very important habitat for yellow bats.

“Yellow bats will be having babies in about two weeks, so if they trim that skirt this time of year we’ll have way more orphans to raise,” he added.