What’s killing all the bats? A terrifying Halloween tale

Mexican Free-tailed bat. Courtesy NPS, Big Bend National Park.

America’s bat populations are facing an epidemic. A disease called White Nose Syndrome (WNS) associated with the fungus geomyces destructans (G.d) has already claimed the lives of millions of bats on the East Coast and is spreading south and west.

The potential loss of our flying mammalian friends could have undetermined consequences for human health, ecosystem resilience, and pesticide use through the loss of the pest control services they provide.

Many bats species roost and hunt on our public lands— which is why providing federal agencies with robust tools and consistent funding to manage wildlife crises like White Nose Syndrome is critical.

White Nose Syndrome affected bat. Photo by Alan Hicks, New York Department of Environmental Conservation.White Nose Syndrome appears to cause mortality during winter hibernation. During hibernation some species huddle together, with many thousands of bats in a single cave. They slow down their metabolic functions in order to conserve energy for the winter. With their immune systems compromised from hibernation, the fungus begins to grow on the bat, first appearing as a white growth on the wings and muzzle. Agitated, the bats prematurely exit hibernation therefore burning critical fat reserves essential for winter survival.

Bats then leave the roost in order to search for food, but their prey are absent in the cold months. The bats perish through fatigue, cold, and starvation; ultimately, resulting in mortality rates between 90-100 percent, according to the USGS and USFWS. It is important to note that WNS is the syndrome causing bat mortalities and G.d.is the name of the spore that grows on the bats. Scientists are unclear of the exact connection between WNS and G.d.

There is strong evidence that the fungus is spread from bat to bat. Researchers suspect that humans may be spreading the spores through their clothes and equipment; although, there is no evidence proving human transmission. The origin of the fungus is unknown although it has also been identified in Europe.

The Fish and Wildlife Service has implemented management plans for WNS issuing cave closures, working with state officials, and recreational cavers in an attempt to slow down transmission. G.d. has been identified in 14 states (map) and White Nose Syndrome in 10 states as far south as Tennessee and as far west as Oklahoma. The Indiana bat and Gray bat are two endangered species highly vulnerable to the fungus and are being closely monitored by federal and state agencies, cave conservancies, and bat conservation groups.

On Oct. 6 the Fish and Wildlife Service announced $1.6 million in funding for WNS and G.d. research. Although this number is an improvement for bat conservation, research and programs, more research is necessary in order to determine the economic, ecosystem, and health effects resulting from a precipitous decline in a species that provides a critical role in the food chain.

Many of our National Parks and public lands have interpretive programs that allow visitors to view bats as they leave their caves en-masse to feed at dusk. A few, such as Carlsbad Caverns in New Mexico and Pinnacles National Monument in California, the latter which The Wilderness Society is working to expand protections for, feature bats as one of the main attractions.

Mexican Free-tailed bat. Courtesy NPS, Big Bend National Park.
White Nose Syndrome affected bat. Photo by Alan Hicks, New York Department of Environmental Conservation.