Little Brown Bats & White-Nose Syndrome

Halloween is upon us and there are many different species of animals that come to mind when we think of this spooky holiday. While some think of critters such as spiders or owls, a personal favorite of mine are the bats. Of the 10 species of bats commonly found in Ohio, the little brown bat (Myotis lucifugus) – once thought to be the most common – can be found in many of your Great Parks!

A little brown bat hangs from a crack on the outside of a building.
Little brown bats certainly live up to their name! (Photo courtesy Donald Althof/Ohio Department of Natural Resources)

Typically, when hearing someone in our area describe a bat, the two most common words are usually ‘little’ and ‘brown.’ Due to the majority of Ohio’s bats being described as such, most are easily misidentified. Some ways to tell the little brown bat apart from the others is by its sleek and glossy brown fur. Their wing membranes (the extension of skin on the wing that lets the bats fly) are dark brown. Their muzzle is furred, and ears are short. These bats grow to around 3 to 4 inches long with a weight of 0.3 to 0.5 ounces. Even though they’re little, they are not the smallest. That title goes to the tri-colored bat (Perimyotis subflavus), the smallest bat in the entire Midwest. Tri-colored bats weigh in at only an average of 0.16 to 0.29 ounces!

A group of little brown bats hang from the top of a cave.
Healthy little brown bats roost in a cave. (Photo courtesy Ann Froschauer/U.S. Fish and Wildlife Service)

The nocturnal nature of bats leads most individuals to feel uneasy about these amazing creatures. The fear of bats often stems from a lack of understanding of them. For instance, did you know that bats play an essential role in pollination and pest control? Recent studies show that bats eat enough pests to save at least $1 billion per year in crop damage and pesticide costs in the United States corn industry alone, according to the U.S. Fish and Wildlife Service. The little brown bats specifically have an estimated capture rate of 1 insect every 7 seconds! As these bats are insectivores, they prey primarily on mayflies, moths, leaf hoppers and plant hoppers. Eating as they fly, little brown bats use their wingtips to knock prey into their wing membrane, then grabbing it with their mouth.

With little brown bats spending their nights assisting us with pest control, they’re in need of our help with the challenges they’re facing. Sadly, this species is now endangered as their population size has declined dramatically over the past decade due to habitat loss and White-nose Syndrome (WNS). White-nose Syndrome is a fungus-caused illness that thrives in the cold. WNS is caused by the fungus Pseudogymnoascus destructans. Once infected, the fungus causes an irritation on the skin of a bat’s wings during hibernation, which causes the bat to wake up more frequently in the winter season, depleting the bat’s stored fat reserves. Ultimately, this infection leads to the death of the bat.

A bat box hangs from a wooden pole.
A bat box (or bat house) provides a place for bats to roost during the day. (Photo: Courtney Celley/U.S. Fish and Wildlife Service – Midwest Region)

Due to continued habitat loss and the unprecedented mortality associated with WNS, these cute animals need our help. Listed below are just a couple ways to help the little brown bat, as well as other bats:

  • Spread the word about WNS and why and how bats are so important to our environment.
  • Turn off unnecessary lights to provide a dark environment for bats. This is the simplest way to improve conditions for our nocturnal friends.
  • Leave dead and dying trees in areas where possible. These can be used as bat roosting sites! Or install a bat box! Bat boxes should be 10–20 feet high in open areas. Work around areas near artificial lights.

Next time you take a hike in one of your Great Parks, be sure to keep an eye out for any bat boxes in the area. Interested in learning more about the little brown bat, other bats native to Ohio, or White-nose Syndrome? I invite you to follow the links to learn more information provided by the Ohio Department of Natural Resources.

Connor Holt
Central Region Nature Interpreter, Glenwood Gardens