Zoo Tales: Bats Often Misunderstood, Under-Appreciated
BY TOM GILLESPIE
Special to The Pilot
OK, at first glance, bats aren't the most exciting or lovable animals in the world. In fact, it's likely that only snakes are more feared and more misunderstood.
But like snakes, bats play an important role in many ecosystems. In addition to some pollinating flowers, bats eat harmful insects. By some estimates, a single bat can consume as many as 1,200 mosquitoes per hour.
First, let's disprove some myths. Bats aren't blind. Most have very good eyesight. They have excellent echolocation, so they don't become entangled in human hair. They seldom transmit disease to other animals or humans. They're not nasty little rodents. Besides actually being mammals, they're also very clean animals, grooming themselves almost constantly to keep their fur soft and clean - much like cats.
They don't destroy crops. In fact, many important agricultural plants, like bananas, peaches, bread-fruit, mangoes, dates and figs, rely on bats for pollination and seed dispersal.
All mammals can contract rabies; however, less than half of one percent of bats do and normally bite only in self-defense and pose little threat to people.
Bats are one of the world's longest-living mammals for their size, with life spans in some species of almost 40 years. They're in the taxonomic order Chiroptera and have those same characteristics as do other mammals. They give birth to live young (rather than laying eggs) and feed them with their milk.
Bats' most distinguishing features are their forelimbs, which have developed as wings. This makes them the only mammal naturally capable of true flight. Although some mammals, such as flying squirrels, might be erroneously thought of as fliers, they are actually gliders that can only travel limited distances through the air.
When bats fly, they don't just flap up and down. If you watch them closely, it almost looks like they're pulling themselves through the air - similar to the butterfly stroke in swimming. Bats use their wings for more than just flying. They can wrap their wings around insects or fruit to hold it while eating.
Common vampire bats (Desmodus rotundus), like those exhibited at the N.C. Zoo, are one of three species of bats that feed solely on blood, a dietary trait called hematophagy. All three species are native to Central and South America and parts of Mexico, ranging from the desert area of northern Mexico to Brazil, Chile and Argentina.
The front teeth in vampire bats are specialized for cutting, and their back teeth are much smaller than in other bats.
Their digestive system is adapted to their liquid diet, and their saliva contains a substance called draculin. This saliva, a natural anticoagulant, is now being reproduced synthetically to help heart patients and has been an inspiration to researchers for stroke treatments.
Vampire bats do not suck blood but rather lap the blood at the site of the bleeding.
They typically feed on the blood of domesticated animals such as cows, pigs, chickens and horses, and require about two tablespoons of blood each day.
Bat colonies are well-structured, with strong social bonds, often grooming each other and recognizing other colony bats with voice and smell. >Their social structure is imperative to their survival, since hungry bats that have not found food that night or are forced to stay behind are sometimes fed from others through a process of regurgitation. >
Nearly 40 percent of American bat species are in severe decline or already listed as endangered or threatened. Throughout the world, bat feces, called guano, is collected in bat caves for its use as a strong natural fertilizer.
Unfortunately, this mining can be deadly to bats, especially during winter months when some species hibernate. In the wild, bats are highly vulnerable to disturbance to their roosts. Some species, especially those with low fat reserves, will starve to death when regularly disturbed and put into a panic state during their resting period. Many species will drop their young (called pups) when panicked, leading to further reductions in populations.
Although vampire bats have been depicted in folklore and films as creepy blood-suckers, they are actually beneficial to man and nature and, like so many other animals thought to be nuisances, are a vital part of our ecosystem.
Tom Gillespie works for the public affairs office of the N.C. Zoo.
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