The Spooky Truth about Bats

October 31, 2013

One of my favorite animals has long been associated with Halloween – bats. These ecologically important species have, unfortunately, long been shrouded in superstition and have a bad rap that isn’t quite deserved. Theories vary as to why, but the fact that most bat species are nocturnal may contribute to the myths. Of course, there’s also that one larger, flashier myth that so easily confuses fact and fiction and always seems to pop up this time of year: Vampire bats.

Vampire bat (© Jennifer Krauel/Flickr)

Out of more than 1,200 species of bats, only three are sanguivorous – that is, they eat blood to survive. These three vampire bat species live in Central and South America – they do not exist in the United States or in the Old World. Interestingly, stories about vampires – the blood-sucking human kind – existed long before people in Europe knew about the New World animals. In fact, the earliest myths about vampires come from ancient Babylonia, and stories of vampires were common during the Dark Ages. It likely wasn’t until Bram Stoker wrote Dracula in 1897, and actor Bela Lugosi immortalized Dracula in the subsequent movie, that people began linking the small vampire bats with the vampire myths.

Despite these negative associations, vampire bats have many unique and amazing qualities. Vampire bats are small, weighing approximately 40 grams. By comparison, the iPhone 5 weighs 112 grams. They are highly social animals, living in large colonies and practicing social grooming. They are believed to be the only bats known to adopt another bat’s young should the baby’s mother die. Scientists have long been interested in their practice of food sharing, believed to be an example of reciprocal altruism. Vampire bats cannot go for more than two days without a meal, yet they sometimes fail to find food. When this happens, a hungry bat will approach a member of their colony and beg for food. The other bat will then regurgitate blood to help the hungry individual. Presumably, this favor will be returned at some point, making the practice beneficial for the entire colony.

Bat with White-nose Syndrome (©USFWS)

Perhaps most relevant to humans, vampire bats have a protein in their saliva that has been found to help stroke patients. When vampire bats eat a blood meal, they make a small bite in their prey animal, and their saliva mixes with the blood. An anticoagulant property in their saliva keeps the blood flowing without clotting so the bat can eat a meal. This anticoagulant enzyme – appropriately named Draculin – has been found to break up blood clots in the brain that cause strokes in humans. Rather than being frightening, vampire bats are fascinating and important species that are contributing to science.

The truly scary news about bats this Halloween is the disease White-nose Syndrome (WNS), which has killed more than 5.7 million bats since it was first discovered in 2006. While vampire bats are not known to be at risk, ten bat species in the United States and Canada are threatened by this new fungal disease. Scientists estimate that the little brown myotis, once one of the most common mammals in North America, could be extinct in less than 20 years as a result of WNS. The implications for our ecosystems, which depend on bats for vital insect control activities, are enormous. For instance, a study in the journal Science estimated the value of bats to the U.S. agriculture industry to be between $3.7 billion and $53 billion per year. With fewer bats, insects are surviving to attack crops and forests – a situation that can only get scarier as we lose more bats to WNS.

Click here to adopt a bat today!

Once one knows more about bats, it’s hard not to appreciate their value to our ecosystems and economy. So instead of being afraid of bats this Halloween, here are some things you can do instead: