Ever since Bram Stoker鈥檚聽Dracula聽(1897) depicted vampires shapeshifting into bats, the flying mammals haven鈥檛 been able to shake their creepy reputation and association with Halloween. But do humans need to be afraid of them?
Definitely not, says Professor of Biology Patrick Bohlen.
麻豆原创 is home to thousands of bats, who for years have taken up residence in a storm drain near the 麻豆原创 Arboretum鈥檚 green house.
鈥淎 lot of the habitats these bats would reside in are being greatly reduced, and they like to roost over water and to be in caves, so that鈥檚 why they are attracted to this open pipe,鈥� Bohlen says. 鈥淲e like to celebrate them, especially around Halloween. It’s a way of just supporting some of the native species that would exist in this area in our urban infrastructure.鈥�
As a tribute to our friend the bat, Bohlen shares some interesting facts and dispels some myths about these furry, flying creatures.
Bats are primarily insect eaters in this part of the world. Some of those insects are pests, so people have calculated there’s a value to that in terms of the insects they eat. We don’t normally think of other animals eating bats, but actually during the breeding season, barred owls, which are night predators, feed a lot on bats. So bats can actually serve a rope higher up in the food chain as well.
I think bats get a bad rap just because they鈥檙e associated with horror films. They come out at night so they鈥檙e nocturnal. They鈥檙e a little creepy because they鈥檙e the only mammal that flies. They have funny little faces. I think they just kind of have a scariness about them for a lot of people that stems from lack of knowledge. They鈥檙e really not very scary animals. There are three species of bats in South America that feed on blood, so I think that creates a Count Dracula association. But I think they have a bad reputation mostly because they鈥檙e associated with the darkness and they鈥檙e just kind of very unusual creatures that look funny.
Some bats, including some of the bats we have in Florida, have adapted so that they can survive extremely high ammonia levels. There are some caves that have bats in them where the ammonia level would knock a person out. But the bats have a way of dealing with ammonia by regulating the CO2 in their blood to neutralizes the excess ammonia. They can tolerate that high ammonia that鈥檚 produced from their waste, the guano that falls to the floor of the roost.
It’s not really fully understood why. They are social animals for the most part, so that plays a factor. It could also be in cold climates they benefit from thermoregulation to stay warmer.
In Florida we have 13 species of bat. I think we have possibly two or three species in the storm drain on campus, but I think the main one is called the Southeastern myotis, known by its scientific name as Myotis austroriparius. The fact that that species name has 鈥渞iparius鈥� in it means they are water-loving bats. They tend to roost in wet areas. Historically, they would have roosted in trees and bottomland, forests, swamps. So the storm water pipes are perfect for them because they like high humidity.
I had a student once who lowered a GoPro camera into the manhole we knew they lived in and took all of these photos. We then laid the photos out flat on a big single two-dimensional map and counted the bats. And there were 5,000 in that one manhole. There could be more, but there were 5,000 in that one roost.
People don’t need to be afraid of bats. They’re relatively harmless. If you see a bat on the ground in the daytime, I would stay away from it. They can carry rabies, so I certainly wouldn’t want to handle a bat that was in a situation like that. There are bat conservancy groups you could call if you find a bat on the ground. But for the most part bats are out at night, flying around and eating insects.
I think the best single place to go to learn about bats in Florida would be the Florida Bat Conservancy. Their website is floridabats.org.
