The Altus Public Library went a little batty on Thursday, June 21 for the Summer Reading Program. Quartz Mountain Naturalist Sue Hokanson invited State Biologist Melinda Hickman to present a program on some nocturnal creatures, bats.
Hickman said that out of the 45 different species of bats in the U.S., Oklahoma, with its varying terrain, has 23 of them. She explained about echolocation to the children and many adults who attended the program. Bats, she said, really use sonar, a type of sound wave, to maneuver through darkness, and to hunt prey. These sound wave frequencies, above human hearing range, tell the bats what size the object is, its movement, direction and how fast it’s going.
Some Oklahoma bats hibernate, since there are periods of time in the winter when there are no insects for them to eat. Some of our bats migrate to warmer areas. Some bats do a little of both. The Eastern Red bat is one type of bat that snuggles down in leaf litter and curls up in its furry tail to hibernate. On warmer winter nights when moths come out, these bats will awaken and feast on moths which would eat crops.
The Mexican Free-Tailed bat is an example of those migrating species which comes into our area. In spring and summer those bats eat a tremendous quantity of insects, especially mosquitoes. The Mexican Free-Tailed bat is Oklahoma’s state flying mammal, given that status in 2006. These bats eat literally tons of agricultural pests in our state.
There is a “maternity cave”used by the Mexican Free-Tailed females, which is located on private property in Mangum. Hickman said the mother bats literally hang by their thumbs to give birth. The pups, all born breech, (feet-first) are one-fourth the weight of the mother. After giving birth, the mother and pup communicate so they will recognize one another’s sonar. Within 45 minutes the umbilical cord dries out. The pup is placed in a nursery cluster of thousands of other pups. When it’s time to nurse (breastfeed) the mother finds her pup by sonar and smell, out of all the others.
Since bats are nocturnal, active at night and sleeping during the day, they look for dark places to roost. Different species prefer certain roosts. Common roosts here include: cliffs, crevices and cavities in trees and tree bark, old buildings, under bridges and some roll up like leaves and hang in trees.
Oklahoma bats range in size from a wing span of six or seven inches to 16 inches. Some of our bats include: Eastern Red bat, the Tri-Colored bat, the big Brown bat (with the 14-inch wing span), the Silver-Haired bat, the Hoary bat, the Pallid bat, the Mexican Free-Tailed bat and the Cave Myotis.
The Eastern Red bat loves to hang out in trees. The Tri-Colored bat is one of the smalled bats with the 6-inch wing span. They hibernate and when the dew forms on their hair, they sparkle like little diamonds, Hickman said.
The Brown bat loves mosquitoes and will swoop low to be near humans up at Quartz Mountain Nature Park, because humans attract mosquitoes.
The Silver-Haired bats love the areas near rivers and creeks. They prefer to roost in the bark of cottonwood trees.
The Eastern Red bat also frequents the habitat near waterways. They frequently give birth to twins, triplets or even quadruplets. Amazingly, Hickman said, the mothers with 14-inch wing spans fly with their pups (babies) on them.
Also living by rivers, the Hoary bat, is Oklahoma’s largest bat, with a 16-inch wing span. The hang in trees and purposely fall to get the lift to fly.
The Pallid bat is pale with big ears which it can roll up. Its hearing is so powerful it can detect the footsteps of insects like the scorpion and the centipede. The little Cave Myotis, common on the prairies, spends its whole life in caves.
Many states have purchased land for bat habitat and bat birthplaces. Our state relies on good conservation techniques from those who own land is necessary to preserving these valuable parts of the our ecosystem. Alabaster Caverns State Park and the Selman Living Laboratory are popular tourist locations for those who wish to study bats, Hickman said.
Bats don’t have many predators, just owls and some hawks. The Barn owl and the Great Horned owl swoop through groups of bats flying out of caves or buildings.
During a question and answer period, Hickamn said there is some evidence that bats in this area may have developed immunity to the white-nose syndrome caused by fungus. The fungus has been found here, but no ill bats have been located here. This fungus loves cold weather and it irritates the little Brown bats living in the Northeast. Hickman said the bats are aroused from hibernation and use up valuable calories that would have helped them survive winter months. Bat caves in the Northeast have been closed to help prevent cross-contamination by humans. Hickman said current research indicates transmission is through bat-to-bat contact. Oklahoma has been monitoring the white-nose fungus situation for three winters now. Hickman said that, if all else is equal, eventually the Northeastern bats will develop an immunity to the fungus too.
“During the spring and summer,” Hickman said, “a bat must eat one-half their body weight to survive. That amount must increase if they are pregnant or nursing young.”
Bat guano, or droppings are used as fertilizer and, Hickman said, it is found in some very unusual places. Guano can be found in mascara, some antihistamines, and even in the original Doritos recipe. A bacteria found in guano is used to break down heavy metals.
Hickman said most people don’t have much success with getting bats to roost in bat houses. She did say if bats are currently roosting in old buildings and bat houses are erected before destruction, the bats may take to the bat houses.
Also in the Q&A session, Hickman said we don’t have any vampire bats in the U.S., except in the very tip of Texas. There they may occassionally have some there.
Sue Hokanson showed the audience the stuffed American Ring-Tailed Cat from near Quartz Mountain Nature Park. The agile and secretive relative of the raccoon lives in the hill country, nesting between rocks. Hokanson said these nocturnal creatures may come out on cool, cloudy days, especially when she is not trying to take their photos.
The Summer Reading Program, held each Thursday afternoon at 2 p.m., is sponsored by the Oklahoma Department of Libraries, the Oklahoma Library Art Council, Sonic, and the Institute of Museum of Library Services.