Say the word Bat – what do you think of?
Most likely Dracula – or vampires. It’s too bat that these furry little mammals have been associated for so long with such nasty monsters. They are one of our mammal cousin, which means that they are warm-blooded, give live-birth, and provide their young with milk just like we do. Their bird-like ‘wings’ are actually long finger bones, adapted so that these mammals can truly fly. These are fascinating animals!
This time of year, most bats have left their hibernation caves (yes, they hibernate through the colder months) and have migrated to caves where they form what biologists call maternity, or nursing, colonies. The following information is taking from the chapter, “Bats Are Mothers Too,” in the book, A Journey for All Seasons by John A. Kinch, published in 2000 by Lyons Press for The Nature Conservancy.
“Some [maternity colonies] contain thousands, if not millions of bats. One such colony is found in Arkansas, in the Ozark Mountains, in a dank and dark cave whimsically known as Blue Heaven.
“The maternity colony here, a modest population, is composed of Ozark big-eared bats, a federally endangered species. (That means that there is a real danger that this animal may become extinct in the near future.) The bat’s range has historically been Oklahoma, Arkansas, and Missouri, though this subspecies is now believed to be extirpated (essentially nonexistant) in Missouri. In Arkansas, the population of Ozark big-eared bats was estimated to be two hundred in 1992.
“Maternity colonies of bats are just what you would expect: aggregations of female bats with their young. While both genders of many species of bats share hibernation caves in the winter, when spring arrives the sexes part ways. The females congregate in caves, where they give birth and wean their young. In most species of bats, the female has only one baby – an evolutionary adaptation to flight, biologists believe, since being weighted down with several fetuses would reduce the endurance and agiity a bat needs to feed in the air.
“Female Ozark big-eared bats roost communally in the pockets of cave ceiling that get the warmest, some up to 60 degrees Fahrenheit. Maternity caves for other bat species can get even warmer, upward of 100 degrees. The warm temperatures of maternity caves are a result, in part, of the body heat given off by each bat. And therein hangs a clue as to why bats form such aggregations. The collective heat accelerates the maturation rate of newborns. A North American bat that hibernates during the winter needs stores of fat to survive. A newborn must be able to fend for itself quickly so it can begin voraciously eating to prepare for winter’s torpor.
“Ozark big-eared bats, born in May or June, are on their own by summer’s end. Maternity bat caves are incubators, of sorts, giving newborn the edge they need to survive. Young bats face not only seasonal perils but dangers within the nurseries themselves. A flightless baby bat that loses its grip on the cave ceiling or its mother’s fur (it has especially large feet and first fingers to minimize this mishap) often does not last long on the cave floor, as predaceous insects and fish (if there’s water below) quickly devour it.
“Nationally, bats have more species on the federal endangered species list than any other group of mammals. Habitat destruction and vandalism have decimated bat populations, and in Arkansas alone three of the sixteen species of bats found there are endangered.”
Q: What is a bat house?
A: A bat house is similar to a bird house, but thinner and without a central hole. Instead, the bottom of the ‘house’ is missing. These houses, placed on trees, can each provide a home for as many as fifty bats! We think of bats as living only in caves, but some species of bats live in attics, barns, the eaves of houses, and even in trees and bushes.
Q: Don’t bats carry rabies?
A. Any mammal can carry rabies. The fact is, less than half of one percent of bats do, and fewer than ten people in fifty years have contracted rabies from North American bat species.
Q. Are there really vampire bats?
A. There is a subspecies of bat that feeds on the blood of other mammals. These bats live in tropical climates, mostly Mexico. They primarily feed on the blood of cattle.
Q. What do other bats eat?
A. Seventy-five percent of the 1000 species of bats in the world are insect eaters. They consume mosquitoes, moths, beetles, crickets and other insects. A single North American Little Brown bat can eat six hundred mosquitoes in just one hour. The remaining 25% of bats are mostly fruit-eating bats who live in the Tropics. They are crucial to pollinating fruits and vegetable crops, and also help to disperse seeds in the rain forests.
I hope you’ve enjoyed learning about these amazing mammals! My home state of Oklahoma is home to nine species of bats – all insect eaters. Several of them are endangered species because of disappearing or disturbed cave habitats.
Nature Connection #21 – Go Batty!
Say the word Bat – what do you think of?