Bats – strange animals often associated in old wives’ tales without much truth. Who are they? Where do they live and what do they look like? Are they dangerous or are they actually quite helpful? And do they need our help?
Who they are may be the easiest. Bats are mammals – they are warm blooded, their babies (pups) are born alive, and they nourish their pups with milk. The mother’s pregnancy lasts from a little over one month to about six months, depending mostly on the size of the species. Since a litter is almost always just one pup, bat reproduction is the slowest of all mammals. Even so, bats account for about one-fifth of all mammals. AnBat Post Earringsd they have been around for at least 50 million years!
They are also the only flying mammal. In fact, the technical name of their order is Chiroptera, which comes from a Greek word meaning hand-winged. Their wing membrane extends from the enormously elongated bones and fingers of their fore limbs to their comparatively short hind limbs. Our two pieces of bat jewelry, the Bat Post Earrings and the Round Bat with Bead Earrings, both feature these dominant wings.
Where do they live and what do they look like? Well, there are more than 1,000 species of bats, and with their ability to fly they have become one of the most widely distributed groups of mammals. You can find bats almost everywhere except the cold climates in the Arctic and Antarctic. Wherever they live they need a place to roost and a place to forage, or find food. They pick roosts in hollows, caves, and even man-made shelters. They are nocturnal animals, and when roosting usually hang head downward by the claws of their hind limbs. According to Wikipedia the largest bat roost in North America is in Austin, Texas, where there is a colony estimated at 1,500,000 Mexican free-tailed bats. These bats eat an estimated 10,000 to 30,000 pounds of insects each night. Incidentally, the Mexican free-tailed bat is the state bat of Texas and Oklahoma (Did you even suspect that some states had state bats?). The only other state with a state bat is Virginia – the Virginia big-earred bat.
What do they look like? As you might guess, over 1,000 species of bats provides for some variation. The smallest bat is Kitti’s Hog-nosed Bat, or bumblebee bat, which lives in Thailand and Burma. It is just over an inch long and weighs about two grams. The largest bat is the Giant Flying Fox that lives in Indonesia and has a wingspan of nearly six feet.
Bats also vary in what they eat. A group of about 200 species known as megabats lives in the tropics and primarily eats fruit. The flying foxes belong to this group. The rest of the bat species belong to the group known as microbats. This group lives just about everywhere and eats insects, fish, and blood, depending on the species. The blood-sucking bats of South America have gained notoriety as Vampire bats, but they are not after humans. They usually walk up to sleeping cattle, bite the animal, inject some blood thinner, and have a drink. In reality, about 70% of all bats eat insects, doing humans a huge favor. In fact, Defenders of Wildlife claims that a single little brown bat can eat up to 1000 mosquitoes in a single hour, and is one of the world’s longest-lived mammals for its size, with a life span of almost 40 years.
Some of the old wives’ tales about bats may have come from this insect eating. First, since they must crush the shells of many insects, these bats have long, sharp teeth that can make them look ferocious. Second, they hunt at night when the insects are out. Third the old tales about bats attacking humans and getting tangled in hair most likely results from the fact that the scent from people attracts mosquitoes and gnats, and the bats really are just after these insects.
So how do the bats find their prey? The microbats and a few of the mega bats use echolocation, sending out sounds and using their excellent hearing and large ears to determine not only where the prey is, but possibly what it is as well. The sounds they emit are high pitched, and are among the most powerful emitted by any animal.
Finally, who, or what, are their predators? There are a lot of bats, but are some species potentially endangered? They have three main enemies – natural predators, humans, and a new one: white-nose syndrome (WNS). Natural predators include bat hawks, bat falcons, and two species of bats (the Ghost bat of Australia and the American False Vampire bat) that feed on other bats.
For centuries some humans have set fires in bat caves to destroy the bats, probably from fear of the animals due to old wives’ tales. More recently, urban development has destroyed bat habitation. In addition, Wikipedia reports that wind turbine farms are leading to much higher rates of death among bats than among birds. Although there is little evidence of direct impact with the giant turbine blades, bats have lungs typical of mammals, and suffer ruptured lungs from the rapid decompression in the wake from these fans. Birds lungs are different, and not so susceptible to decompression.
And that brings us to white-nose syndrome (WNS). The July/August 2011 issue of Smithsonian magazine has an excellent article on this developing catastrophe. WNS first appeared in North America in 2006, and has spread rapidly since. The disease apparently is the result of a fungus that attacks bats when they hibernate, a period during which their metabolism slows down and their immune system almost shuts down. To quote from the Smithsonian article, “The fungus may spread from bat to bat, and when the animal colonies disperse in the spring, the fungus may persist in cave sediment … . Bats with WNS rouse more frequently from their winter torpor, which causes them to waste precious body fat at the coldest time of the year. At this time there is no known cure, and some have predicted that the brown bat, once common almost everywhere, could be extinct in 20 years.
Can anything be done? There are some competent people trying. So let us go away with this: the bat, through his insect eating and pollination (which comes with his finding insects) is a good friend of ours. Maybe it is time for us to try to befriend the bat.