Wild Thing Wednesday shares a fond goodbye for now to our summer bats.  Eight species of bat have been found in Wisconsin; the hoary bat, silver-haired bat, eastern red bat, evening bat, eastern pipistrelle, little brown bat, and big brown bat.  Several of these species are found in Horicon, with the little brown and big brown being most common.  Since getting a good view of a flying bat at night can be almost impossible, scientists studying bats often identify them by sound, using special recording equipment to “listen” to bat echolocation calls too high pitched for humans to hear.  All of Wisconsin’s bats are insect eaters, with larger bats targeting moths and beetles while smaller ones are most interested in mosquitos and other small flies.  Many of the insects eaten by bats can be major problems for our crops and gardens, making them a natural pest control.  Since insects are not available in winter, Wisconsin’s bats must either migrate to where food is more readily available or hibernate in place.  The hoary, silver haired, and eastern red bats will migrate, while the other five species are believed to hibernate, usually in a natural cave or an abandoned mine.  Hibernating bats build up a small fat reserve in late summer, and use it to sustain them through a long winter of dormancy.  Unfortunately, many of Wisconsin’s hibernating bats have been negatively affected by a non-native fungus that causes a disease known as white-nose syndrome.  Bats affected by this fungus are woken up during hibernation, and burn through their energy reserves too quickly, which results in starvation.  Many areas in Wisconsin have seen bat populations decline by over 90% in recent years.  Fortunately, there are ways to help struggling bat populations.  Many hibernating bats will form nesting colonies in artificial bat houses like the ones at our facility, and forestry practices that leave some hollow trees standing can give bats extra space to successfully raise their pups.  We hope to see our own bat houses in use, and hope that they can give a leg up to some struggling but vital wildlife.
Photo: Big brown bat by Jack Bartholmai