by Paul W. Wilson
Bats have been associated with Halloween since ancient times, even before there was a Halloween. Many people observed large numbers of bats during the fall when they are feeding at night or migrating to their winter hibernacula after leaving the maturity colonies and foraging territories of the summer.
The ancient Celtic festival Samhain (pronounced saw-wen), meaning “Summer’s End,” marked the oncoming darkness of winter. The Celts built large fires at night during the festival. The fires attracted insects, and bats flew in to feed on the insects. The Celts believed that bats were dark spirits.
Christianity heavily influenced people’s views of bats during the Middle Ages. In the Bible, the bat is depicted as an inherently unclean animal unfit for consumption, perhaps because bat roosts can develop a layer of guano, or feces, on the floor, which was rightfully associated with illness. But it was Dante’s Inferno that solidified bats as an allegory for the Devil and his domain. Dante’s still famous poem described the Devil’s wings as looking like those of a bat.
Despite this negative image from the past, bats are very important to the environment by feeding on large numbers of insects that they find by echolocation. With new technology, bats can be identified by echolocation acoustic detectors at night.
Bats are in the mammalian order Chiroptera and are the only mammal capable of true and sustained flight.
Bats in Oklahoma
Oklahoma has 22 species of bats — 20 in the family Vespertilionidae (common bats) and two in the family Molossidae (free-tailed bats).
My science club students at Picher-Cardin High School and I were involved with research on gray myotis and Ozark big-eared bats from 1975 to 1983 with Dr. Everett M. Grigsby at Northeastern State University in Tahlequah.
We captured bats and banded them to determine population and migration
patterns. We also installed gates at cave entrances to protect the bats. Dr. Keith Martin and Bill Puckett continued to work with Grigsby until his death. Martin now works with Mark Peaden to keep on with the research.
The gating of cave entrances continues, and at present, about 48 entrances are gated. Some caves have multiple entrances.
Five species of Oklahoma bats are on the endangered species list or will soon be included — gray myotis, Ozark big-eared bat, northern long-eared bat, Indiana bat, and eastern pipistrelle, or tricolored bat, which will likely be added this year. Martin stated that the population of gray myotis is stable in the protected caves, and the Ozark big-eared bat has a population of about 2,500, located entirely in Oklahoma and Arkansas.
The Keen’s myotis, or northern long-eared bat, has a very low population. The Indiana myotis has a low but stable population in southeastern Oklahoma and southwestern Arkansas. The population of the tricolored bat has been declining because of the white nose virus, which has affected several cave-obligate bat populations.
In western Oklahoma, some caves have very high populations of Mexican free-tailed bats, which might number several million. It is an amazing view at dusk when the mass of bats flies out of a cave like a dark cloud. Some predators try to capture bats during flight. I have observed common barn owls attack the flight from behind with limited success. Swainson’s hawks attack head-on or from above with less success.
Some bats stay in trees, house attics, the underside of barn roofs, or other dark, safe places where they are not disturbed. When bats find a favorable winter hibernating location, they generally return year after year. At Northeastern State University, a large population of a species known as big brown bats has hibernated in the attic of Seminary Hall for more than 50 winters. Gray myotis and Ozark big-eared bats hibernate in caves in Arkansas and southern Missouri.
Some people build bat houses to attract bats, but they have a low success rate.
What To Do if You See a Bat
During summer, bats should not be disturbed because they are producing young. From October through April, they should not be disturbed because of hibernation.
Bats that appear in places that they have not normally frequented will generally move to a new location within a few days. However, for safety’s sake, if you encounter a bat — especially a bat that appears to be sick — it is best to leave it alone. Consult a professional if the bat needs to be removed.
The four carriers of rabies in North America are bats, skunks, opossums, and raccoons. Carriers do not show signs of the rabies virus but can transmit it in saliva, generally through bites. However, rare cases of transmission via aerial contraction have occurred from long-term exposure in caves that have high populations of bats. The only cases of aerial contraction I am aware of are among bat researchers who live in caves with Brazilian free-tailed bats or Mexican free-tailed bats, with colonies numbering in the multimillions.
Most of the cases of rabies in bats have been among Mexican free-tailed bats, and those cases are very rare.
But if you see a bat this Halloween, be careful and respectful.
Writer’s note: Dr. Keith Martin provided some information and comments for this article.
This gray myotis is from an endangered species in northeastern Oklahoma. Photo courtesy of Paul W. Wilson.
