Creature Feature: Hey Batta Batta
When it comes to Halloween and the month of October, there are some animals that serve as a symbol of sorts to the month and holiday. Three, in particular, come to mind: spiders, whose numerous eyes and legs unsettle many. Black cats, which are usually associated with witches. And lastly is our nocturnal flying friends that I will be discussing more in-depth with you today. That being said, let us don our Romanian cloaks and tune in to an article that Bruce Wayne himself would be impressed with.
Bats are very unique mammals that belong to an order called Chiroptera, a word derived from Greek meaning “hand-wing”. They have received this title because the digits on their forelimbs are elongated and spread out. Between each finger or digit, a thin membrane called a patagium is spread out across the hand, and extends to the hindlimbs and tail. It is this that gives the bat the ability to fly, the only mammals that are able to do so. There are some kinds of “flying” squirrels, but they use their patagium for gliding during a descent. In other words, falling with style. Of the approximately 1400 species of bats found throughout the world, the state of Michigan has nine, and they all come in different colors, shapes, and sizes.
Silver-haired bat resting against a tree trunk during daylight hours.
Ever hear the saying “blind as a bat”? While it may be true that humans perceive objects with more color and sharpness compared to bats, the statement is largely untrue. This false perception may be referring to the special skill that bats heavily rely on for feeding and navigation called echolocation. As a bat flies around in the dark, they release a high frequency sound from their mouths, and use their ears to listen to the echo that is made. The echo then provides the bat information, such as the shape and size of nearby objects within their environment. Bats are not the only animals able to perform this skill. What's more, fruit bats do not have the ability to use echolocation.
While bats have a cool and unique lifestyle, they are not without threats to their population. Since it first appeared in New York state in 2006, researchers have taken note of a fungal disease new to North America dubbed white-nose syndrome (WNS). The fungus that causes WNS targets the bat during its hibernation phase. If a bat becomes affected, white fungal spots begin to appear around the muzzle, ears, and wings. This causes the bat to wake up more frequently during hibernation and burn the fat that they have been saving for the entirety of their hibernation. Therefore, bats with WNS face starvation before spring even arrives. Furthermore, an analysis of the fungus by Leopardi et al. (2015) has led to the conclusion that the fungus had originally come from Europe, which explains why North American bat populations are heavily affected while European populations are affected less. Blehart et al., (2009) provides a detailed account of WNS as a new pathogen.
Little brown bat with white-nose syndrome. Credits: NPS/von Linden/New York Department of Environmental Conservation.
While the image and appearance of bats may seem frightening for some due to their appearance, they are very important animals that help provide balance to an ecosystem. They have the potential to capture hundreds of insects per hour, and during the cold months will either migrate, or reside within caves and mines. Kurta and Smith (2014) reveal that of the 119 abandoned mines they surveyed in Northern Michigan, 82 of them contained hibernating bats (before WNS). During the warmer months, bats will favor places with water and forests, if available, as that is where they will most likely find insects to feast on. Keep an eye out for these tiny but mighty mammals the next time the sun goes down!
Click here to learn more about the bats of Michigan
References and Further Readings:
Blehert, D. S., Hicks, A. C., Behr, M., Meteyer, C. U., Berlowski-Zier, B. M., Buckles, E. L., ... & Stone, W. B. (2009). Bat white-nose syndrome: an emerging fungal pathogen?. Science, 323(5911), 227-227.
Kurta, A., & Smith, S. M. (2014). Hibernating bats and abandoned mines in the Upper Peninsula of Michigan. Northeastern Naturalist, 21(4), 587-605.
Leopardi, S., Blake, D., & Puechmaille, S. J. (2015). White-nose syndrome fungus introduced from Europe to North America. Current Biology, 25(6), R217-R219.
Submitted by Zach Mork, Naturalist, September 2022