Watching The Bats Of Wisconsin

University Place: Joel Knutson Explains How Citizen Science Can Build Consensus
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Richard Hurd (CC BY 2.0)

Wisconsin is home to seven species of bats.

From loon-watchers to fighters of invasive species, Wisconsin is home to many groups engaged in citizen science. It's a practice in which people volunteer to monitor plant and animal species in the wild and collect local data about their status, and usually share this information with professional scientists to help inform their research.

These grassroots enterprises enhance people's connections with nature and with each other — and they can help improve overall habitat for all species, including humans. One example of a citizen science effort of this type in the state is the Wisconsin Bat Monitoring Project, which tracks the presence of and identifies trends with these animals. It's one of several citizen-based monitoring networks administered by the Aquatic and Terrestrial Resources Inventory, a program of the Wisconsin Department of Natural Resources.

Joel Knutson, an educator with University of Wisconsin-Extension Oneida County, works with the Bat Monitoring Project. In a July 29, 2015 talk in Rhinelander, part of the Northern Lights Tour put on by the Wednesday Nite @ the Lab lecture series, he described his experiences monitoring bats and other species. Titled "Beyond Counting: Wisconsin Bat Project and the 'Positive Multiplier Effects' of Citizen Science Monitoring Programs," his talk was recorded for Wisconsin Public Television's University Place.

In and around Oneida County, different groups have tried to advance property and shoreline management regulations intended to benefit lakes and people's use of them, but directing landowners what to do with their properties can be problematic, Knutson said. Therefore, another approach is to seek to expand interest in nature through citizen science and find commonalities among, for example, people who volunteer to monitor boat landings to keep aquatic invasive species from spreading and others who monitor bats, loons or other wildlife.

"So the key is that tying these activities in into our broader goals of healthier lakes and shorelines to a point where, without the force of law, without the force of zoning and conflict, that you start to create a sense of a new normal," Knutson said.

When monitoring bats, Knutson and other volunteers have an echo locator device they can use, ideally, he said, while motoring on a lake at sunset, cocktail or beer in hand. The best time of day to monitor bats is about 30 minutes after sunset, he said. Typically, bat program monitors are usually responsible for monitoring at least one route a month selected by wildlife biologists who are looking for specific data. Alternatively, Knutson explained, volunteers can monitor their own neighborhoods and lakes.

The echo locator device records high frequency noises the bats emit when they are flying around. The different sounds have different meanings, including whether bats are hunting, roosting or warning off a competitor, Knutson said.

Key facts

  • Wisconsin is home to seven species of bats, all of which migrate to seek warmer conditions over the winter. The state's three species of tree bats (Silver-haired, Eastern red and Hoary) tend to migrate south for winter. Wisconsin's cave dwelling bats (Little brown, Big brown, Eastern pipistrelle and Northern long-eared) tend to hibernate in caves and mine shafts, which means some may actually migrate north for winter.

  • Bats tend to emerge from their hibernacula in late April and early May. They establish their summer roosts in breeding grounds through June and July. As summer ends, bats begin their swarms back to hibernacula in late August through September, and then start resting  for the winter in October.

  • Bats are one of the few species native to Wisconsin that prey on the emerald ash borer, an invasive beetle that is killing ash trees in Wisconsin.

  • White-nose syndrome is a serious threat to bats. The disease is a fungus that overheats hibernating bats' bodies, compelling them to consume their fat stores and awaken too early. They bats are subsequently hungry, and so leave their caves (or other hibernacula), but because there is no ready insect food supply in winter, they starve or freeze to death. (The May 20, 2016 edition of Wisconsin Public Television's Here And Now features an interview with Wisconsin Department of Natural Resources biologist J. Paul White about the disease and its effect on bats around the state.)

  • Bats (and wildlife in general) require appropriate habitat. Drinking water sources need to be clean. Native plants attract insects. Forest edges and dead trees and snags help many species, and wood piles and rock walls make good roost sites.

  • Bat houses can help provide habitat. A DNR guide provides directions for building and maintaining these structures.

  • University of Michigan researchers sequencing the hearing genes of echo-locating bats have discovered a common protein gene sequence between dolphins and echo-locating bats that suggests convergent evolution.

Key quotes

  • On a goal of citizen science: "[O]ne of the big benefits of what we're doing in citizen science is giving people the sort of connections and confidence that do kind of make sense of the complexity, the amazing complexity of the natural world."

  • On the value of citizen science: "[T]here's more and more research that's coming out that really unifies a lot of different aspects of citizen-based monitoring that's focused on improving our shoreline habitats."

  • On why concentrations of fish, birds and mosquitoes vary among immediate neighbors: "[W]e know with songbird recruitment that [with] micro-level decisions, an individual property owner can have a big payoff. You can have a huge nesting bird population on your property and your neighbor might not have any. ...[I[f songbirds are important to you, what are ... some of the decisions you can make as a landowner? Why is the fishing better over by my neighbor? Oftentimes it's a function of the fact that whether you bought into the property or not, the aquatic vegetation around or coarse woody habitat around your property's been removed, where it still has a more natural environment somewhere else. Fish tend to gravitate towards those environments. ... [T]he big one in the last couple of years is why are the mosquitoes so much worse over on my property than they were somewhere else."

  • On the importance of bats as a species: "We know that bats are critical linchpins in the ecosystem. … But in terms of their impact on the food chain, it's very, very difficult from both their significance in pest control and down south in pollination to even imagine an ecosystem without bats. And it's very, very difficult to think of northern Wisconsin environment that would be bearable during the summer without them."

  • On bats' use of echolocation: "They're bouncing signals off of prey. They're bouncing signals off of trees. They're bouncing signals off of water and if they're in the house, they're also bouncing signals off of you. … They're both navigating and simultaneously hunting for prey when they're sending out those signals."

  • On people's perceptions of bats: "Half the world seems to think that bats are terrifying and are going to kill us all, the other half, myself included, once you get up close and personal, thinks they're one of the most adorable mammals on the face of the earth."

  • On rabies and handling bats: "[I]t's certainly well under 1 percent. It's not to say however that you don't take certain caution. And whether or not a bat is rabid or not, a direct bite would still sting a little bit. ... I'm very very comfortable in telling people that if they encounter bats in a problematic area — if they net them, if they put them in a box — they're not unsafe to handle. But you do need to exercise caution and one would certainly want to have gloves. This is after all just a cute little, little brown bat."
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