Batty about bats

Photo credit Wisconsin Department of Natural Resources

It seems like it’s always “National Something Day,” with most everything getting its turn in the lime light. For me, some of those days are more fun than others, and some I like to point out more than others.

April 17, 2020 was Bat Appreciation Day. In Wisconsin, we think more about bats as they are darting above our heads when we are sitting around the campfire than at most other times of the year. However, with White Nose Syndrome being found in New York in 2007, and moving steadily west, we started to think about them in the winter time as well. Since the detection of the disease, it has been found in 33 states and 7 Canadian provinces.

White Nose Syndrome, WNS as it is knows, is a fungus that affects cave-dwelling bats while they hibernate. It is characterized by a white fuzzy appearance of a bats’ nose and wings. Bats affected by WNS are often seen flying around outside their hibernacula in the winter long before they should emerge. They often come out, looking for water. They usually seem disoriented and can be unable to fly. They quickly succumb to the extreme temperatures, or starve to death, as no food sources are available and the cold temperatures cause them to use up food store much more quickly.

The Wisconsin Bat Program recently reported that approximately 6.7 million bats have died due to this disease since it has been found in the United States. Thirteen species in all have been confirmed to have the disease nationwide with eight more carrying the fungus without exhibiting signs of the disease.

The program’s recent report stated there were over 200 hibernacula in Wisconsin including natural caves, mines, abandoned rail tunnels and old beer cellars. The 2019-2020 winter survey done on these hibernacula showed the disease was still widespread and, even worse, was still decimating bat populations. Every site surveyed this past year showed signs of the fungus, which grows well in these damp, cool conditions, as one would expect. While some sites had decreased to no bats at all, in others a 72-79 percent decline was seen.

According to Bat program lead and DNR ecologist Paul White, there were some bats, however, that were surviving with the disease. He felt the bats had learned to adapt somehow, possibly choosing hibernating sites that were colder and less hospitable to the WNS fungus. It was found that, in some places, year-over-year survival was increasing, even though WNS was still present in the bat community. This was good news!

So, why should we care? That is a common question some ask. Those of us who study the outdoors understand that everything from opossums to penguins are related. For others, those connections are not as obvious. So, what is the deal with bats anyway?

Bats eat insects. Most of us know that. They dive bomb around us, swooping through and snatching insects out of midair as we finish our late picnics or sit around the campfire in the summer. But the impact they have on agriculture is much, much bigger.

Bats, is has been estimated, save billions of dollars per year in pesticides and other control measures for those in the field of ag. One recent estimate I saw was as high as $53 billion per year. Even the most conservative estimates are in the billions of dollars. This total, wherever it falls, takes into account only the direct impact of bats, and does not take into account the downstream effects, if you will, of harm done to other wildlife, native plants, and even humans, when increased pesticides are needed to control a variety of insects on crops.

In the big scheme of things, then, these little bats are big business. This makes their plight important. Of the eight bat species in Wisconsin, all four of the cave-dwelling species, little brown bats, big brown bats, long-eared bats, and the Eastern Pipistrelle, are all listed as as threatened.

The good news is, there are many ways people can help. As many have heard multiple times, I am a citizen science geek. I love learning about anything outdoors. The Wisconsin Bat Program, and, at least in Wisconsin, your local county Land and Water Conservation Department, are great resources to help people learn more about how they can help bats.

Bat houses are fairly simple to make and erect. There are directions on how to accomplish this on the Wisconsin Bat Program website. This is actually a section of a larger citizen science website, so feel free to look around if you happen to visit there. There are many opportunities to monitor bats, too. Summer surveys are done around the state, in an attempt to see which bats are where and how populations are surviving and adapting.

I agree, it seems creepy at first – little mice with wings, as some people say. But if you can get out on a lake with an eco-locator that can capture the sounds of bats that we cannot hear with our “naked ear”, and later get to hear those sounds – it really can change your mind about them.

I remember Joel Knutson, a young man with a passion for bats, coming to talk to a Master Gardeners group a few years back. He brought audio of bats he had been out monitoring. It was really a cool experience to hear them darting through the trees, using their sonar to not run into anything at a dizzying pace. There was one recording where the sound went quickly dead for not even a second, and then picked up again. It did not take much for the group to interpret the fact the bat had been chasing an insect, and had caught it in midair, causing the brief pause in the action as it swallowed it’s prey. It was a really interesting discussion overall, but I think the audio really made it stick for all of us.

Bat Appreciation Day. On the surface, it might sound about as important as National Pickle Day (although at one point in history, I am very sure those were more important than as a burger side or a stir stick for a Bloody Mary). But, in reality, bats provide a much-needed service in the food web. I encourage everyone to hit the link for the Wisconsin Bat Program above and check it out with the whole family. Bats really are an interesting and important species.

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