Endangered designation raises further alarm about bats in Black Hills

The federal government’s designation of an endangered bat species hit home this week in the Black Hills, where the bats lurk in caves and abandoned mines.

The U.S. Fish and Wildlife Service designated the northern long-eared bat as an endangered species on Tuesday.

That announcement came as part of an effort to save the species from extinction by white-nose syndrome, a fungal disease.

Once a species becomes listed as threatened or endangered, it receives special protections by the federal government under the Endangered Species Act. This includes protection from harassment, hunting and trapping. The law also protects against interfering in breeding or degrading critical habitats.

Under the act, federal agencies must consult with the Fish and Wildlife Service to ensure projects they fund or authorize — such as timber harvests and prescribed fires — will not further jeopardize a listed species. 

Brad Phillips, a Black Hills National Forest wildlife biologist, said the northern long-eared bat is one of 12 bat species in the state. 

“They are a cave-roosting species in the wintertime,” Phillips said. “They’ll hibernate in caves and abandoned mines, and that is when they’re susceptible to this cold-loving fungus referred to as ‘white-nose syndrome.’”

First documented in the U.S. in 2006 and in South Dakota in 2018, the disease has killed millions of bats across North America. At some sites, 90 to 100 percent of bats have died. 

The disease is named for the white spots that appear on infected bats. It attacks the skin of bats while they’re hibernating. As it grows, the disease causes bats to become active and burn up the fat they need to survive the winter. 

Several South Dakota bat species are affected by white-nose syndrome, Phillips said, with the hardest hit being the northern long-eared, little brown, and tricolored bat. 

“We are seeing a lot fewer,” Phillips said. “And while I can’t always put my finger on white-nose as the source all the time, I have no doubt that it is playing a part.”

Phillips said South Dakotans should care about the decline. Bats reportedly contribute about $3.7 billion worth of natural insect control for farmers in the U.S. each year.

“So, just the fact that you don’t have to spray as much insecticide around the country is one reason that we really should all care that we have bats in our ecosystem,” Phillips said.

To avoid the possible spread of the disease by humans, Phillips said cave explorers should decontaminate gear before and after entering caves, and leave bats alone.

“Primarily the fungus is spread from bat to bat, but people can spread it,” Phillips said. “We recommend that people do not go caving in the wintertime just out of respect, trying to not disturb these bats.”

Phillips also said the public can help by not killing bats that nest in homes and not treating them as pests. He said there are a number of non-lethal ways to get rid of bats, including catch-and-release and non-lethal repellants. 

The Fish and Wildlife Service said it will also work with wind energy companies to reduce the likelihood that bats will strike turbines. Operators can limit the danger by curtailing blade rotation during bats’ migration season and when winds are low.