BY THE MASKED BIOLOGIST
Something is very different this year. I knew it was only a matter of time, and its arrival was inevitable, but I was not prepared for it to happen so abruptly. I am talking about the notable reduction in the number of bats. Normally when I am out on the lake at dusk or later, I am surrounded by bats, swooping and twittering as they catch mosquitoes and lake flies, or skim along the surface of the water taking a drink. But not this year. I would estimate that the numbers of bats seen this year compared to years prior is reduced by as much as 80-90 percent. Calls from homeowners or cabin owners asking for help with bats are dramatically reduced as well. Wild Instincts also reports that the numbers of bat calls, bat rehabilitations and observations is a mere fraction of what normally come in.
The cause of this reduction has to be white nose syndrome (WNS). This is a harmful disease that affects all species of hibernating bat, caused by inhalation of fungal spores. While the spread to Wisconsin’s hibernacula (bat hibernation sites) was slowed by protective measures, it’s arrival was unpreventable and inevitable. It causes bats to wake from hibernation frequently, burning valuable fat reserves. It also causes them to move closer to the mouth of the hibernation structure where they are more vulnerable to hypothermia. The impacts are immediately apparent; the bats die where they hibernate and only a small number of bats emerge alive the following spring. The affected locations are reporting bat number reductions of 80-90 percent, much like my own observations.
While recent scientific observations indicate there may be a small number of bats that are resistant to WNS, I don’t hold out much hope that this will turn around the devastating effects of this disease on bat populations on any impactful scale. Bats have what we call low fecundity, which means they do not reproduce very rapidly. Bats are mammals, the only mammals capable of true flight.
Because of their size and appearance, people often refer to them as flying mice or flying rats. They are very different, though. Mice might have a litter of young every two months, with 6-12 young per litter. Most of our bats only have one, possibly two pups per year, and they all only reproduce one time a year. Furthermore, bats gather in groups to raise their young, keeping their pups in a nursery of sorts, which is another way for diseases to spread. All of this bodes ill for the future of the bat.
Rachel Carson wrote her renowned book Silent Spring to warn the public about the devastating impacts of pesticides and chemicals on wildlife. Aldo Leopold famously eulogized the loss of the passenger pigeon, and wrote of his concern that his children might never hear the “goose music” of the Canada goose flocks that were continually diminishing in his time. Will anyone eulogize the bat? Will I be sitting on a dock at sunset someday with my grandchildren, telling them tales of a mysterious hairy animal with bony, leathery wings that used to twitter and chirp as it swooped and darted at the tip of my fishing pole? The future of the bat is unclear, but not bright. Take time now to burn bats into your memory, so that we all can educate future generations about how easily and quickly an abundant wildlife species can be lost—and how, despite our knowledge and technological advances, we humans were helpless to stop it.
The Masked Biologist earned a bachelor of science degree from a university with a highly regarded Wildlife Biology program. He has worked for natural resource agencies from the Rocky Mountains, across the Great Plains and into the Midwest, which provided opportunities to work with a variety of common and rare fish, plant and wildlife species. Follow The Masked Biologist on Facebook.