Government work at the speed of bat

Recently there’s been some hubbub about the city of Burlington purchasing a shy five acres of land from the school district for a retention pond over by the old James Madison school. As I understand it, the pond is a part of the stormwater project the city will be working on this year, but the purchase had to be fast-tracked due to, of all things, bats.

Yes, bats. Those winged creatures of the night that haunt children’s dreams and which are a staple of Halloween decorations the world over.

But aside from the legend, mythology, and overall misunderstanding of these creatures, what is so important about bats as to risk delaying a municipal construction project over them?

Here’s the short answer: The particular situation we have with this stormwater project is due to the Indiana bat, a federally endangered species. Part of the federal protection of the species is to not cut trees during times bats may be roosting in them. 

This retention pond required the clearing of a bunch of trees in advance of construction, therefore those trees needed to be cut before the end of March. In order to do that, the city had to purchase the land. Quickly. By government standards, the city and the school district moved at light speed to make that happen.

Now here’s the longer version.

The Indiana bat is a migratory species and its range covers most of the eastern United States, Iowa included. It is a highly social species that hibernates, roosts, and rears young in groups. Almost half of all Indiana bats (over 200,000) hibernate in caves in southern Indiana with four other states supporting hibernating populations over 40,000. The bat’s scientific name, Myotis sodalis, even acknowledges this social component. Myotis means “mouse ear” and sodalis is Latin for “companion.”

Iowa does not support large numbers of hibernating bats but does get them during the summers, hence the tree cutting restriction.

To be listed as federally endangered, a species must be at real risk of going extinct. Like the dinosaurs, or the passenger pigeon. Every single member of the species gone, never to return.

The Indiana bat was listed due to rapidly declining populations resulting from human disturbance of caves, habitat loss, and other factors. Now the species is also being impacted by white nose syndrome, a fungal disease that has killed millions of bats of several species since it was first discovered in 2006. The US Fish and Wildlife Service estimates there are about 537,000 Indiana bats left, down from 664,000 at the onset of white nose syndrome and just more than half of what the population was when they were listed in 1967.

As I mentioned above, these bats are very social. When they migrate to places like Iowa in the summer, pregnant females will form “maternity colonies” where 100 or more of them will roost in trees with peeling bark. Each female gives birth to only one offspring, or pup. In those roost trees, the mothers will nurse their young, leaving the tree only to forage for food.

Side note here: Much of the forest management work we do at places like Big Hollow, which is known to support Indiana bat populations in the summer, is geared toward promoting tree species such as shagbark hickories and other native hardwoods, as well as standing dead trees, that these bats rely on.

The fact that one single tree, or group of trees, can support 100 or more reproducing bats is the main reason for not cutting potential roost trees during the bat’s migration season. Cut down the wrong tree and you might wipe out the entire reproductive capacity of all the Indiana bats in a particular region. But cut the trees down before the bats arrive, and they’ll just have to find somewhere else to roost.

Yet some will still argue that a pesky bat, endangered or otherwise, shouldn’t get in the way of progress.

I’ll skip the philosophical question of whether it’s okay to knowingly send a species further toward extinction or whether a particular species has a right to existence in the face of human progress. Instead I’ll stick to the practical argument of a bat’s value in controlling insect populations, which play a sizeable role in agriculture and human health, which I’d argue are rather important to human progress.

An Indiana bat can eat half its weight in insects in a single night. Weighing in at a mere one-quarter ounce, that may not seem like a lot until you realize that the average mosquito – the species responsible for things such as yellow fever, malaria, West Nile virus, and canine heartworm – weighs one-15,000th of an ounce. Do the math, and one bat is wolfing down over 1,800 mosquitoes every night. Multiply that times a 100-bat maternity colony and that’s more than 180,000 mosquitoes consumed nightly. Over a summer, that one maternity colony literally removes tens of millions of mosquitoes from the landscape. But since they’re equal opportunity foragers, some of those millions are just as likely crop or garden pests.

Maybe getting those trees cut before April doesn’t seem like such a hassle now. And really, is it that large of a price to pay, considering the alternative?

So, kudos to the employees and the board and council members that pulled this deal together not at the usual speed of government, but at the speed of bat.