Bats are the good guys and need our help

With bat populations in decline worldwide, and a new disease devastating bat populations in the Eastern United States, Wisconsin wildlife officials are turning to sophisticated electronic equipment and a cadre of citizen volunteers to monitor the status of the state’s eight bat species.

“Bats get too little respect,” said Dave Redell, a bat researcher with the Department of Natural Resources Bureau of Endangered Resources.

Redell said bats have been long misunderstood – with people often associating these winged mammals with horror movies, Halloween and vampires.

“In reality, bats play an important role in the overall health of our ecosystem. They are really amazing creatures and as the primary predator of night-flying insects they do much to help keep mosquito and other insect populations in check,” he said.

Bats are important predators of many insects, including some that carry diseases such as West Nile and malaria, and others that can devastate farm crops. For instance, Redell notes that a single colony of 150 big brown bats can protect local farmers from up to 33 million or more rootworms each summer.

“They are hard workers. They show up about the same time each evening and labor tirelessly until dawn. With access to clean water, shelter, and areas to forage for insects, bats of Wisconsin will consume tons of insects each summer. In the process they help balance local ecosystems without chemicals and without leaving a carbon footprint.”

Redell said scientists believe nearly 40 percent of American bats are in severe decline or already listed as threatened or endangered, and that “worldwide, losses are occurring at alarming rates.” Decreasing bat populations worldwide, he adds, could result in increased human dependence on insecticides.

And now scientists are monitoring a new disease – called white-nose syndrome – that is devastating populations of bats in their winter hibernation caves across parts of the eastern United States and is currently moving toward the Midwest. White-nose Syndrome is the most alarming threat to North American bats in recorded history.

In an effort to find out more about these mammals and their ecology in Wisconsin, the Endangered Resources Program monitors the eight bat species found in the Badger State through a federally funded State Wildlife Action Plan grant. Four of the species – hoary bat, eastern red bat, silver-haired bat, and northern long-eared myotis – are identified as “Species of Greatest Conservation Need.”

The remaining four species – eastern pipistrelle, Indiana bat, little brown myotis, and big brown bat – are listed as species with additional information needs. The Indiana bat, once found in Wisconsin, has not been verified in the state since the 1950s and is federally listed as endangered. Relatively few people have searched for this species in the state.

“Bats are difficult to study because they are nocturnal, fast-flying mammals whose calls are above the range of human hearing,” Redell said.

All Wisconsin bats use the technique known as echolocation to locate and intercept insect prey in flight.

Using electronic tools for ultrasound detection, citizen volunteers and DNR staff can listen for bats and record their calls using a hand-held bat detector. Each species of bat has it own distinct call. A global positioning system (GPS) coupled with the detector automatically records the position of each bat passing by along with the route traveled during the survey.

Armed with this sophisticated acoustic bat monitoring equipment provided by the DNR, citizens from across the state hike or boat along specific routes recording bat echolocation calls to detect and monitor bat movements and determine the species distribution throughout the state. More than 160 surveys have been completed in 29 counties during the first two of three survey seasons in 2009. Results are analyzed and presented on the WI Bat Monitoring Program Web site (wiatri.net/ inventory/bats) for volunteers to view their own surveys as well as every other citizen bat surveyor.

After a short training session new members of the volunteer bat crew may begin monitoring bats in their region using the acoustic detectors.

“To date there have been numerous people coming out across the state for bats,” Redell said.

For example, Juley and Gary Kennedy of the Racine County Conservation League purchased an acoustic monitor for their organization with money raised, in part, from proceeds from a bingo raffle. They have since surveyed many areas in the southeastern part of the state.

Redell said citizens who care about the future of Wisconsin’s bats and want to get involved can be part of a new white-nose syndrome surveillance project. In addition to the acoustic monitoring project, folks can help with the newly organized bat roost monitoring project. People who know of existing roost sites such as attics, chimneys, bat houses, barns or natural rock outcrops, tree snags or caves and who are willing to monitor the sites a couple times each summer, can contact Redell at David.Redell @Wisconsin.gov or White at (608) 267-0813 for more information.

Anyone finding dead, sick, or dying bats near their home are encouraged to fill out an online report available on the WI Bat Monitoring Program Web site.

Bats become more noticeable as young begin exploring areas around their roosting spots.

This is the time of year that young bats are becoming mobile and sometimes find their way into homes and buildings. Bats flying around in a house are looking for a way out of the building or to their roost. Redell says the best way to deal with these bats is to open doors and let them find their own way out.

If they are on a wall or ceiling people can take a container such as a coffee can or butter tub and place it over the bat. Take a piece of cardboard or rigid paper and slip it along the rim of the container, trapping them in. The bat can then be released safely outside.

“This a good time of year to start thinking about ‘bat proofing’ for next year,” Redell said.

To keep bats from coming back inside right now, bat exclusion funnels can be built if the homeowner knows where bats are coming in. Look around the house for bat droppings, which indicate bat entrances. Once the entrance is located, place the bat exclusion funnel over the hole so bats can get out but not get back in. This should only be used once the young bats are mobile so they are not stuck inside. In late fall or winter, entrances can be sealed.

“Although most people do not want bats in their homes, these animals are very beneficial and will eat many insects. Bat houses are a good way of providing bats an alternative place to stay and take care of some back yard insects including mosquitoes without having the extra company in the house.”

More information on bats of Wisconsin is available on the Wisconsin Aquatic and Terrestrial Resources Inventory bat monitoring Web pages and on the Wisconsin bats page on EEK! Environmental Education for Kids. For more information on bat proofing, attracting bats to bat boxes, construction plans for bat boxes, and exclusion funnels and much more see the Bat Conservation International Web site. For more information, contact David.Redell @Wisconsin.gov or Paul (John) White at (608) 261-0813.