Volume 35, Issue 3, 2016

Turning Vampire Myths Upside Down (Or Right Side Up)

Curious, caring and sharing, the real vampire bat bears little semblance to its popular portrayals


common vampire bat leaps on the ground Desmodus rotundus Credit MerlinTuttle.org
Vampire bats' thirst for blood has driven them to evolve an unexpected sprinting
ability. Most bats are awkward on the ground, but the common vampire bat
(Desmodus rotundus), can bound along at more than 1 meter per second.
Photo: MerlinTuttle.org

Planning on seeing any horror movies this Halloween? You might just see some swarms of bats, holding true to a time-honored tradition of equating bats to agents of evil. Pity especially the poor vampire bat, who’s taken the brunt of it all.

Yes, it’s true, vampire bats drink blood. There’s no way around that knee-jerk ick factor, with their too-wrinkled faces and too-toothy smile. Let’s face it: no one ever loved a jab from a mosquito or a syringe, let alone being bitten.

Out of the more than 1,330 species of bats that inhabit the Earth, there are only three that only drink blood: the common vampire bat (Desmodus rotundus), the type most people are familiar with; and the rarer hairy-legged (Diphylla ecaudata) and white-winged (Diaemus youngi) vampire bats. The latter two prefer birds, while the common is often seen snacking on livestock like horses, cows and pigs. The reality of these unloved animals is that they have surprisingly strong social networks, don’t mind sharing and need to be quite clever to survive.

A pair of white winged vampire bats Diaemus youngi feed on the foot of a chicken Credit J. Scott Altenbach
A pair of white-winged vampire bats (Diaemus youngi) feed on the foot of a
chicken.
Photo: J. Scott Altenbach

How bats became vampires and then just bats again

The idea of the man-shaped vampire long predates the European introduction to the bat variety. Cultures the world over have had their own vampire mythologies for centuries, but blood-drinking bats were unknown in Europe prior to the 16th century exploits of Spanish conquistadors in the New World.

Named “vampires” after their own tales of exsanguinary ghouls, the fact that the vampire bat also drank blood merely added another dimension to a well-established mascot of the night—like black cats and spiders, anything that conducts its business after sundown must necessarily be malevolent. It took a couple hundred years, but eventually the vampire bat joined the popular horror canon.

Though we missed the premiere of Georges Méliès’ Le Manoir du Diable by a century or so, his 1896 silent film has been called the first-ever vampire movie, thanks to its depiction of a large hovering bat transforming into a man. Méliès’ film predates even Bram Stoker’s famous novel, Dracula, which was published the following year.
Even before that, an 1847 Gothic “penny dreadful,” Varney the Vampire, contained illustrations of its main antagonist sporting large bat wings. But Stoker gets the credit for explicitly bringing the two together in his text.

“Stoker was looking for words that had some connotation of evil, something to be afraid of,” said Elizabeth Miller, a Bram Stoker scholar and professor emerita at Memorial University of Newfoundland. As a plot device to get the character of Lucy to awaken suddenly in the middle of the night, a large bat flapping at the window does the trick: “He just puts it in his story presumably only to make readers shudder,” Miller added.

Stoker also either didn’t know or chose to overlook the fact that vampire bats are really very small—just a couple of inches long. And as for vampires being particularly at home in the Romanian region of Transylvania, well, that’s another thing that just leaked into the public consciousness after the release of Dracula.

“The connection between bats and blood is seen more as a touristy, external attraction than something that’s really based in local folklore,” said BCI Director of Communication and Public Engagement Micaela Jemison, who couldn’t resist asking everyone she came across about bats and vampires while on a recent visit to Romania. “People there seem to have a relatively positive or neutral opinion about bats—in the farming districts we visited, the people there know that bats are part of the ecosystem. They’re not necessarily afraid of them.”
With ever-greater awareness of the benefits of having bats around, Miller said she has seen a dwindling of the bats-as-evil portrayal in literature and film. They can just be bats again.
“There’s more of an appreciation of nature now,” she noted. “People are looking at bats a little differently these days. I can’t think of a recent popular vampire novel that uses bats. It turns a book into comedy once you do.”

Common Vampire Bat Desmodus rotundus mother and juvenile credit Uwe Schmidt
A mother and juvenile common vampire bat.
(Desmodus rotundus) Photo: Uwe Schmidt

Trick or treat, scratch my back

As any parent of young children will tell you, making sure the kids are well-fed and presentable is a high priority of the early years of their lives—sometimes requiring that they sacrifice some of their own food to fill a hungry belly.

A vampire bat mom would definitely relate: Stop by your local colony in Mexico, Central or South America, and chances are, any mom there might recently have shared some of her own hard-won food with others in her colony.

There’s a lot at stake. If a vampire bat doesn’t eat every two to three days, they’ll starve, but getting a full meal with that kind of regularity is a tall order. So they share—and the gift is often reciprocated, though not necessarily just between family members, or even within a short time span. The payback seems to be casual and long-term, as between human friends.

“They have these cooperative relationships that I think are functionally analogous to friendships that you’d see in humans or primates,” said Gerald Carter, who studies the social relationships vampire bats form with one another at the Smithsonian Tropical Research Institute in Panama. “One trait of friendship is that there is reciprocity, but it’s not immediate. The more you form a social bond, the less formal the reciprocity becomes.”

Carter seeks to explore the notion that vampire bats share food with non-family members partly as a way to hedge bets against direct family catastrophe: The better relationships one has with individuals outside their immediate circle means the better chance of assistance if the family falters.

He’s also found that outside of direct family bonds, food-sharing relationships are strongest between unrelated bats that groom each other regularly.

Bram Castle
Bran Castle, located on the border between Transylvania and Wallachia
in Romania, is commonly known as "Dracula's Castle" despite
there being no evidence that Stoker knew anything about this
fortress.
Photo: Micaela Jemison

Scary smart

Behavioral adaptations aside, another aspect of vampire bats made clearer in recent years is just how very keen they are. In hindsight, perhaps it’s obvious that they must be, since the simple act of eating requires great cleverness on their part—one remarkable eating strategy is to run up to their quarry along the ground, which aids in remaining concealed from the target.

Susanne Sterbing D’Angelo, a neurology researcher who studies bats at the University of Maryland, spent some time as a young researcher in the lab of renowned German vampire bat expert Uwe Schmidt.

Schmidt’s lab worked to train vampires to fly through obstacles for various experiments related to echolocation. For one experiment, D’Angelo put three trained bats into an obstacle maze for a blood reward. Despite being untrained for over six months, they all had an immediate 90 percent success rate.
“These guys are smart, and don’t seem to forget quickly,” D’Angelo said.

Carter believes that the work on vampire bats’ intelligence and social structures makes them more agreeable characters, and that researchers have only begun to scratch the surface of understanding their full capabilities.

“People don’t realize bats are socially complex and really intelligent,” Carter said. “There are so many cool things going on with their social complexity. I hope that will give people more respect for them.”

Hairy-legged vampire bat (Diphylla ecaudata)
Photo: MerlinTuttle.org

Fun Fact: Vampire bats don’t “suck” blood!

The truth of how vampire bats drink blood is more analogous to a kitten lapping up milk than the sucking and slurping that horror movies would have us believe.
After locating a target and climbing aboard undetected, vampire bats make a tiny gouge with their razor-sharp front incisors. Their teeth are so sharp that they generally make a painless bite, not waking the often sleeping donor. Here they settle down to lap up about a tablespoon of blood.




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