April 17 is International Bat Appreciation Day!
There are more than 1,200 species of bats around the world, seven of which can be found in Minnesota. Which bat do you relate to?
Bats have a reputation for being scary, disease-ridden creatures of the night—an undeserved label for such an ecologically important group of animals. Understandably, encountering a colony of hairy, flying animals with large ears that scream endlessly into the dark can be a bit jarring, but bats mean well. They just aren’t great at first impressions.
Bats are hugely important for ecosystem health. One bat can eat more than 1,000 mosquitoes in a night—multiplied by the thousands, sometimes millions of individuals in a single colony. Keeping insect populations under control is helpful not only for your late-night gatherings, but for the survival of other organisms, too.
Agricultural crops also benefit from bat activity. In some parts of the world, nitrogen-rich guano, or bat droppings, is harvested from large bat roosts and used as fertilizer. Bats are also an important source of pest control. The presence of bats near agriculture fields significantly reduces crop loss due to insect pests, increasing yield and reducing the need for harmful pesticides.
Not all bats eat insects, though. Larger bats, such as fruit bats found in the tropics and subtropics of Asia, Africa, and Oceania lack the ability to echolocate, using their sense of smell to select ripe fruits instead of insects. Some bat species are carnivorous and specialized to hunt specific prey, including fish, frogs, other bats, and blood! Other bats feed on nectar, acting as important pollinators for many species of plants, some of which bloom only at night, specifically for the bats.
Unfortunately, many species of bats are in danger. White-nose syndrome (WNS) is a new disease that has been spreading across North America in recent decades. It is caused by a cold-loving fungus that attaches to and ingests the skin of bats, mostly on exposed areas such as the wings and nose. Infected bats are unable to hibernate effectively, and wake up more frequently during the winter months, which burns fat reserves that were meant to last through the winter. Many infected bats starve to death because they are unable to produce enough energy to survive through the winter. WNS is spread primarily through bat-to-bat contact, which makes it easily transmittable in large colonies.
In Minnesota, four of our seven species have been exposed to WNS. Some populations have dropped by over 90 percent since WNS was first detected in Minnesota in 2013. A cure has yet to be discovered, but extensive measures have been taken to help minimize the spread of WNS while ongoing research looks for a solution.
Help us celebrate International Bat Appreciation Day by recognizing the important ecological roles these little, fuzzy aviators play.