International Bat Week comes to a close

International Bat Week has come to a close, but that does not mean people should forget about bats. They are not only an important part of the ecosystems in which they live, but the are important to humans as well.

It makes sense for International Bat Week to be the week leading up to Halloween. For decades movies, TV and even books have portrayed bats as harbingers of doom, flying around during the night looking to turn into a vampire and suck the blood of their unsuspecting victims, turning them into creatures of the night as well. But, in reality, only three species of bats feed on animal blood, and two of these species specialize on the blood of birds. 

Bats save agriculture tens of billions each year by decreasing the amount of pesticides producers need to use. In one study done recently, bats increased crop yields over 1.4 percent by taking care of the insects that were harming a corn crop. Not only did corn where bats were not excluded produce more, but it was also found to be less susceptible to fungal infections and had lower concentrations of fumonisin, which is a fungi-produced toxin that is a health hazard to livestock. The presence of this toxin greatly reduces a crop’s market value. Seventy percent of the world’s bats are insectivores, feeding on insects at night. Many can eat thousands of insects each night.

Worldwide, there are over 1,450 species of bats. There are eight species of bats in Wisconsin. The big brown, little brown, northern long-eared and tricolored bats are all listed as threatened species.

Bats face a number of stressors. Habitat degradation and destruction is one of those. Human habitation and changing land use has meant less and less wild habitat left for bats. As with habitat for other species, humans have a chance to help bats, as well, with their landscape practices. Studies have shown that even small habitat improvements, such as a bat house, or simply allowing a lake shore to remain full of native plants, rather than creating a lawn all the way to the water, can do much to help the plight of these nocturnal dive bombers.

Another common plights with many other species is climate change. Climate change could prove problematic to bats. Bat Conservation International said that, in the next 15 years, climate change is expected to impact 82 percent of bat species in North America. This could mean sharp declines in some species and potentially others disappearing altogether. Because bats are so integral in the ecosystems where they are found, researchers have said it is crucial to find out more about how climate change will affect those species in order to find ways to help mitigate those effects. 

“Extreme weather events continue to increase in severity and frequency,” the Bat Conservation International website states. “Widespread wildfires, prolonged drought, higher temperatures and stronger storms all affect bat populations around the world.” Habitat can be destroyed by extreme weather events. Even migratory bats can be affected as weather patterns change the timing of migration. There may be a phenological mismatch in the timing as bats reach some areas expecting certain food sources that are not available. While extreme storm events can knock out roosting locations in breeding areas, droughts, too, can be especially problematic for bats. This is especially true for pregnant and lactating female bats who have a high dependence on water.

One of the big threats to cave-dwelling bats in Wisconsin is white-nose syndrome. Since white-nose syndrome was found in 2006, it has killed millions of bats. In some species, it has been responsible for declines of some populations of over 90 percent. The disease was first found in Wisconsin in 2014.

When it comes to cave-dwelling bats, the good news is that humans can play a part in not moving white-nose syndrome from one place to another. Spelunking, or exploring caves and caverns, is a great pastime. But those going into caves where bats are, or potentially could, be hibernating, should take care to ensure they do not move that fungus from one hibernacula to another. 

There are over 200 known hibernacula in Wisconsin. When spelunkers and others enter a cave or other possible hibernating place of bats, they can easily move any fungus that may be present to the next location they plan to hike. The spores that cause white-nose syndrome can stay viable for weeks, months or even years. For that reason, it is important to completely sanitize any gear or clothing that has been in a cave or other bat hibernacula before heading to another location that could potentially be a hibernating spot for bats. 

All dirt and debris should be removed from items before cleaning. Many commercial and home washing machines, the protocol stated, with sanitize cycles, will help to decontaminate clothing after removing dirt and debris. For clothing and equipment that can be submerged, submerging in water of at least 131 degrees Fahrenheit for at least five minutes will decontaminate it. For items that cannot be submersed, the protocol includes using cleaners such as Isopropyl alcohol wipes, bleach, or ethanol. Brand names are also listed in the protocol such as Clorox products, Formula 409 Antibacterial Kitchen All-Purpose Cleaner, Lysol All Purpose Cleaner or Wipes and Sani Cloth Germicidal Disposable Wipes.

All equipment and clothing, including hiking boots and shoes, should be thoroughly cleaned and decontaminated, and left to dry completely, before entering another cave or area where bats may be present.

Hikers should also pay special attention to their vehicle in which they arrive at, and depart from, their hiking location. Floors, seats and carpeting should be cleaned as well as other surfaces that may have come in contact with clothing or gear.

The goal of International Bat Week is to bring awareness of bats to people and to help people understand the importance of these nocturnal mammals on the landscape. 

For those interested in learning more about bats, The Wisconsin Bat Program provides guidance on creating habitat, bat houses, and even asks volunteers to monitor for bats through different programs. 

The Wisconsin Aquatic and Terrestrial Inventory Resources is a repository for many different citizen science programs in the state, including The Wisconsin Bat Program. Those looking for more information on creating habitat, how to build a bat house, or how to get involved as a volunteer monitor, can visit the website at wiatri.net.

Beckie Gaskill may be reached via email at [email protected].