COLUMBIA (AP) - The population of the northern long-eared bat, a species once common in Missouri caves, dropped from 2,684 in 2015 to only seven last winter, which could lead to a "domino effect" on the food chain and cave ecosystems, conservation officials said.
The Missouri Department of Conservation surveyed more than 300 caves and mines in the winter and found the alarming results when compared with surveys of 375 caves and mines in 2015, the Columbia Missourian reported.
Shauna Marquardt, a biologist with the U.S. Fish & Wildlife Service in Columbia, said the bats' disappearance from numerous caves where they were seen in the past was caused by white-nose syndrome, which has decimated bat populations across the U.S. The northern long-eared bat is especially vulnerable to the disease and has been the hardest-hit species in North America, she said.
Searchers found few bats or found bats that were emaciated and had visible fungus caused by the disease, she said.
The sharp decline of the species could interrupt the natural food chain and other aspects of cave ecosystems, Marquardt said, and might increase nighttime pest populations, some of which prey on crops.
White-nose syndrome causes bats to wake up during hibernation, depleting their energy and causing them to die from starvation. Research to control the disease in caves continues, Marquardt said, but no effective solution has been found.
Kirsten Alvey-Mudd, executive director of the nonprofit Missouri Bat Census, said she saw two northern long-eared bats when she surveyed 200 caves for her organization and odds of finding more of the bats were "very slim."
It's possible populations of the bat are living in caves that haven't been surveyed, Alvey-Mudd said, but it's more likely the disease has killed them.
Northern long-eared bats were added to the state's endangered species list by the Missouri Department of Conservation in March.
They have been listed as threatened by the U.S. Fish and Wildlife Service since 2015.