Missouri Cave and Mine Survey Shows Bat Population Dive

Apr 18, 2017

Credit Dave Thomas / Flickr

Results from a 2017 survey of Missouri caves and mines show that the population of a bat species previously common in the state dropped dramatically from previous years. The survey results reveal that the number of northern long-eared bats in Missouri has taken a dramatic hit due to White-Nose Syndrome.

The syndrome is caused by a fungus, which can disturb bats’ hibernation and cause them to die from starvation. In the 2015 survey of 375 caves and mines, surveyors found 2,684 northern long-eared bats. For 2017, just seven bats of that species were found in 500 caves and mines.


Shauna Marquardt, a biologist with the U.S. Fish and Wildlife Service, said right now it’s hard to determine the long-term effects of the population drop.

“If you lose a keystone species, such as a bat species, from an ecosystem and they are responsible for the primary organic input into something like a cave system,” Marquardt said “There could be some collateral effects of that and there likely would be.”

She said possible effects include increases in the number of night-flying insects like agricultural pests, which bats consume. Marquardt says that this decrease in the northern long-eared bat numbers is the most severe researchers have ever seen in Missouri. According to Missouri State Parks, White Nose Syndrome was first found in Missouri in 2010. There is no cure for the syndrome at this time.

However, it's hard to say anything definite about the northern long-eared bat population because they are difficult to count, and there are so many caves and abandoned mines in the state. Shelly Colatskie is a cave ecologist at the Missouri Department of Conservation.

She said that due to the sample size of caves and mines, researchers cannot definitively say that the bat population has declined throughout the state.

“We just know that we’ve seen major drops in the caves that we’ve done over the past several years,” she said.

Colatskie says the survey is a team effort, completed by a variety of agencies and organizations such as the Departments of Conservation and Natural Resources, the Missouri Bat Census, the U.S. Fisheries and Wildlife Service and other volunteer groups.