Fatal bat fungus epidemic claws its way into Texas

Biologists say 6 counties affected; full-blown disease not yet present

Hundreds of bats take flight into a coral dusk, emerging from their colony’s host, the Waugh Bridge, as local joggers stop to gaze at the sky.

“It’s incredible to watch them take flight, especially when the sun is setting,” said Houston native Erica Vaughn. “I bring my kids here on the weekends, and their faces light up when they see the bats. It’s magical.”

To think of a deadly disease ravaging bats makes Vaughn shake her head. Yet, White-Nose Syndrome, a fatal fungal disease, has rapidly killed millions of hibernating bats since 2007 when it was first discovered near Albany, N.Y. The Texas Parks and Wildlife Department confirmed late last week that the fungus has now reached Texas.

“It’s awful to think about them being gone one day.”

Bat Conservation International and Texas A&M University biologists detected the fungus, “Pseudogymnoascus destructans,” on three bat species in six Texas counties early this year.

Katie Gillies, the director of U.S./Canada imperiled species at Bat Conservation International, said it was difficult for the community when news broke of the fungus’ detection.

“This is a really big deal, having it here in Texas,” Gillies said. “We were shocked to see it in Washington, but seeing these results — it was like a gut punch.”

After taking skin swabs from bats, researchers found molecular traces of the fungus, determining the full-blown disease has not yet arrived in Texas. Its eventual arrival is anticipated.

Since its discovery, White-Nose Syndrome

has killed millions of bats in over 30 states and six Canadian provinces. In some places, the fungus has resulted in a 90 percent decline in winter bat numbers, Texas parks officials said.

“The fungus thrives in colder climates, and it remains to be seen if it will have the same serious impacts in Texas as it has in northern states,” said Jonah Evans with Texas Parks and Wildlife.

The fungus infects hibernating bats’ skin on their muzzle, ears and wings, according to the National Wildlife Health Center. It is typically spread bat-to-bat, considering they congregate in large numbers. As the fungus becomes more prolific in the environment, bats become carriers of it to other sites.

Gillies said humans have also played a role in spreading the fungus.

“People can pick it up on their shoes and their clothes and inadvertently carry it to another place,” Gillies said. “That’s how we think it got to the U.S. in the first place.”

In hopes of combatting the disease, BCI is working with state wildlife agencies and the national WNS Disease Surveillance Working Group on strategies to adapt response efforts to the disease. With bat surveys, they are aiming to expand the national surveillance effort for the deadly fungus.

Texas hosts 32 of the 47 bat species found in the U.S. Bracken Cave on the outskirts of San Antonio hosts the world’s larg- est bat colony with more than 15 million Mexican free-tailed bats. In downtown Austin, the Ann W. Richards Congress Avenue Bridge hosts the largest urban bat colony in the world, estimated at 1.5 million.

There are 11 bat species found in the Houston area, the Mexican free-tailed being the most common. Research conducted in 2006 concluded Mexican freetailed save cotton farmers in south-central Texas more than $740,000 annually by reducing crop damage and pesticide use in the U.S., according to Bat Conservation International.

For years, Houston area locals and curious out-oftowners have visited the Waugh Drive Bridge to watch the bats’ emergence from their cave around sunset every night.

May through August is “baby bat season” at the bridge, according to the Houston Parks and Recreation Department. In flight, the younger bats are described as looking like “large butterflies” because of their rapid wing beats.

Gillies urges bat-watchers to keep a safe distance from the caves, not only to preserve bat habitat, but to lessen the chances the fungus will spread.

Vaughn and her family keep a safe distance from the colony when watching their emergence but intend to be even more careful in the future.

“I would hate to think that we had a part in spreading this,” she said.