It’s Halloween season, a time when bats appear in holiday decorations and spooky stories. But beyond their eerie reputation, bats are year-round neighbors in Kentucky and a vital part of our environment.
Matthew Springer is an associate professor of wildlife management at the University of Kentucky. His work focuses on wildlife ecology, human-wildlife interactions and conservation outreach.
I spoke with Matthew about Kentucky’s bat species, the threats they face, and what people can do to support them.
This conversation has been edited for length and clarity.
Ayisha Jaffer: So let's start with the basics. How many species of bats do we have here in Kentucky, and which ones are the most common for people to actually see?
Matthew Springer: Technically, we have 14 species that are really considered residents of Kentucky that spend a substantial amount of time here. And then we have two oddballs: the Seminole bat that was detected in western Kentucky and southern Kentucky that we're not sure is really a true resident of Kentucky. And then we have the Brazilian free-tailed bat.
AJ: Which species do we see mostly?
MS: The more common bat species that people are going to interact with are going to be the big brown bat, which is really closely tied to human dwellings. It does quite well in things like barns and chimneys and attics. Occasionally, you'll have species like the red bat. And then there's species like the little brown bat, which is also one that will live along human dwellings and do pretty well in urban and suburban environments.
AJ: When we talk about population trends of these species, what are we really seeing? Are bat numbers going up, going down, or just shifting around the state?
MS: I think most people have heard about the fungal disease — the white-nose syndrome — that hit bats pretty hard here in the last almost two decades. And specifically in Kentucky, we've had several of our species that got really hammered because many of them live in caves, where, unfortunately, the fungus can spread through those hibernating bats and really caused major declines in many species. Overall, bats in general could be doing better.
AJ: What is that disease, and how does it attack the bats?
MS: The disease is a fungus that lives in moist, cool environments. It was brought over, we believe, potentially from cavers. And what it does is it slowly changes the physiology of the bat. If you think about that in terms of a species that shuts down its metabolism in the winter to stay alive, if it wakes up in the middle of the winter and it's burning fat, it slowly degrades their overall physical health and causes them to usually pass away in the winter.
AJ: Is this the main challenge in Kentucky, as far as affecting the bat populations?
MS: For bats, in terms of challenges, like many wildlife and insect species, there's a lot going on in our environment. Things are changing constantly. There's human development going on. So you have habitat fragmentation that's occurring.
You potentially have other types of management strategies. Think about the agricultural environment. We use a lot more pesticides than we ever did before. All of our bats are insectivores, so if you think about [people] constantly spraying pesticides, it's probably reducing food availability.
There's been some really interesting work in terms of forestry practices that our department at University of Kentucky has done looking at harvesting trees that are going to benefit bats.
The white-nose syndrome probably is one of our biggest challenges in the state with the species that we have.
AJ: What are some of the ways bats benefit our ecosystem here in Kentucky?
MS: It really gets down to pest management services. They are eating many of the insects that cause us problems in terms of human health.
AJ: What do we know is the best practice for helping bats, whether you're a homeowner or renter or just someone who spends time outdoors?
MS: If you have bats in your yard that you can tolerate, and it’s not a public health concern, don’t do anything. They put themselves there for a reason. They know where the best place to be is.
You can do things like reduce your pesticide use to kill insects. That’s always going to benefit bats, since the intention is usually to reduce public health risks with mosquitoes, but pesticides don’t only kill mosquitoes unfortunately. It also reduces prey availability [for bats].
So if you can tolerate [bats in your yard], plant some more natives, reduce pesticide use — you’re doing pretty good.