Bats are in double trouble: Bat species that migrate long distances are being killed in wind turbines, while White-nose syndrome is devastating bat species that migrate shorter distances. Meanwhile, homeowners routinely kill bats when they find them in their houses. But we need bats (just not in our attics!), so safe and humane removal can be done via a “bat exclusion.” That's the focus of the Halloween installment of WEMU’s “The Green Room".
Barbara Lucas: I'm at the 13th Annual Great Lakes Bat Festival at Washtenaw Community College. Attending is the Kimball family of Chelsea. They recently moved into an old farmhouse which they share with a small colony of Big Brown bats. Here’s Gabe Kimball, on why he likes them:
Gabe: For one, they are so cool to look at! Also we have a lot a lot less mosquitoes than in the city even. We call it farm TV when we watch the bats leave.
Lucas: Also at the festival is Rob Mies, Executive Director of the Organization for Bat Conservation. He offers to teach the Kimballs the key steps to a bat exclusion, evicting bats without killing them. On the way to the Kimball farmhouse, he tells me why we should fear a world without bats.
Mies: Bats consume such large numbers of insects in the United States that US farmers benefit $23 billion annually from insect control. So would we be seeing insect-borne diseases spread more? Absolutely!
Lucas: As we pull in...
Mies: That's an old house!
Kimball child: We’ve actually seen where they go in. Mies: Cool, show me!
Lucas: Mies is here to give advice, Kimballs will do the work later. His first tip is that although it might seem logical to plug their main passageway first, that’s actually the last step. Nate Kimball is anxious to get started.
Nate Kimball: We have seen as many as 50 come out at a time. We like having bats around, it's fun, but just not in the house.
Mies: Those fifty Bats may not sound like a big deal but when 90% of homeowners hate bats and are killing bats, that's when it's a really big deal.
Lucas: Step one: installing a bat house.
Mies: OK, so I brought a couple of bat houses. There’s one…
Kimball kids: Ooh, those are cool!
Mies: If you don't put up a bat house, they are going to move into another spot, they’re going to move into another building or they’re going to leave!
Lucas: Step two is locating and plugging holes in the farmhouse.
Mies: Each spot besides the main exit point should be sealed up before you do anything to the main spot. Because if you do that, they just move to another spot, and you're just working harder.
Nate: Like “Whack-a-mole?” Mies: It’s just a constant… No! Don’t ever say “whack-a-mole”! [laughter]
Lucas: Mies says it’s surprising how small a hole a bat can fit through.
Mies: A dime is pretty small, a nickel? …for sure. Kimball: We have a lot of those! [laughter] Mies: You’ve got a lot of nickels! The thing is, you also want to keep all the wasps and stuff out too.
Kimball: For sure…
Mies: I will want to get up on this roof, right here, this shorter one, if that's okay with you. This is bat guano… Barbara, are you able to hear us at all?
Lucas: Unfortunately, all the action is going on above me. But if the kids aren’t afraid, I shouldn’t be either, so up we go.
Mies: What we are looking at here is a really typical place where bats are getting up inside. This has come apart over time. If you know they are coming out of one main spot, you put this up along the whole rest of the way, and then that way they can’t get out there, they can’t get out there, they can’t get out there. You are basically pushing them towards one spot. All right, then…
Lucas: Finally is step three: creating the one-way exit tube which is key to the system’s success.
Mies: What you want to do is have it about like that.
Kimball daughter: So the end is in midair?
Mies: Yeah! When bats come back, they are going to land here, but they can’t flip back inside, and so we’ve evicted them out, humanely, and they can’t get back in.
Lucas: Back down to terra firma (to my relief!)…
Mies: It's so funny that it's so simple. But places charge a lot because it's so dangerous! They have high liability insurance. But there’s also hours and hours and hours that you are going to have to do...
Lucas: While the Kimballs are do-it-yourselfers, most people pay to have the work done, and Mies says some services do it right, and some don’t. He recommends before calling a company, go to BatConservation.org.
Mies: We have a lot of information on our website. Read through that, and then quiz the people that will be doing it. ‘How are you going to be doing this? When are you going to do it?’ We wouldn’t want to do this eviction in June or July. Because babies aren't flying. Kimball: They would be left behind. Mies: And they are going to die in your house.
Lucas: He says regardless of time of year, never plug all the exit holes until performing an exclusion.
Mies: It happens every winter, someone says, “Oh I'll just wait until the bats leave and then I'll seal up the holes,” and I'm like, “Well how do you know the bats aren’t hibernating in your attic? Don’t do that!”
Lucas: With no exit from the attic they may end up in your living spaces. A common and preventable mistake which after today, the Kimballs will be sure not to make. Next stop is renowned bat expert Dr. Allan Kurta, of Eastern Michigan University, who was on the team to first document the white nose fungus. Dr. Kurta tells me eleven different bats species are infected.
Kurta: I do think that the white nose syndrome has the potential to be one of the worst wildlife calamities on the continent since the Europeans arrived. You can talk about the passenger pigeon but that was a single species. You could talk about the decline of the bison but that's a single species. What we are dealing with here is a whole suite of species so I think the impact is going to be much greater.
Lucas: He says the fungus grows in caves, and fortunately not all bats species live in caves. But unfortunately….
Kurta: It’s not just white nose syndrome, because white nose syndrome is impacting the species of bats that hibernate underground. But wind power is resulting in the deaths of hundreds of thousands of bats across the continent now every year. So we are knocking off large numbers of long-distance migrants with wind power, and we are greatly affecting the bats that migrate shorter distances and hibernate underground with white nose syndrome.
Lucas: Dr. Kurta says there ARE things that can be done to make turbines safer for bats, such as only turning them on at higher wind speeds when bats don’t fly, and shutting them off at night during bat migration season. He says small profit losses are worth it to prevent wholesale collapses of colonies due to freezing and starvation.
Kurta: If all of your friends are gone, who are you going to cuddle with? And who's going to help raise your young, and who's going to tell you where the good bugs are found and stuff like that? So once the populations go down and down and down, if you have a colony of three-hundred little brown bats is that “colony” going to be able to function if there is only five or ten? We don't know that.
Lucas: He fears cascading repercussions, for instance...
Kurta: I can see increased use of pesticides because of this.
Lucas: Kurta says bats eat the two biggest pests of corn and soybeans, so potentially, farmers need apply less insecticide. He says woodlots are crucial habitat.
Kurta: What most people don't realize is that the majority of bats on the continent during the summertime are living in trees.
Lucas: Out in Chelsea, the Kimball farm has a plethora of trees and a minimum of pesticides—a great habitat for bats. It’s encouraging that they’re helping their bat colony, not annihilating it.
Mies: Have you ever heard bats? They just sound like little squeaking [he imitates them]…
Lucas: …which may not be nature’s most popular noise, but if these animals that provide us with free, totally organic insect control are wiped out in our area, it may someday be music to our ears.