One of my favorite tabloid headlines from the now-defunct Weekly World News was this: "Vegan Vampires Attack Trees." I can just see it -- a particularly menacing vegan vampire, perhaps draped in an organic cotton cloak (wool would be inappropriate, right?), lurching toward a helpless tree, preferably maple.
But I'm here to discuss something nonvegan and decidedly bloody: the vampire bat. A few weeks ago, I wrote a quiz on the tiny mammals for Discovery Earth. And I think like many people would, I went into it as an apologist for vampire bats. I was right on one count -- most bats aren't vampires. Only a few species living in South and Central America consume blood for a meal. But I was wrong on another: Vampire bats will bite humans, and they'll do it very much on purpose.
Bats not only drink human blood, they're doing it more often, according to National Geographic News. As ranching operations in South and Central America grow, the vampire bat's ideal blood source, passive domestic livestock, becomes more plentiful. And with more livestock come more vampire bats. That's why you'll find large colonies close to ranches.
Fortunately for ranchers and people who live nearby, passive livestock make a more appealing target than angry humans not in the mood for a bite. Consequently, the incidence of human rabies isn't high on ranches, despite the large bat populations -- there are just too many cows around for bats to look elsewhere.
But in the Amazon, local residents aren't so lucky. There's little livestock in the area, and development has depleted many of the bat's natural food sources. Faced with prospect of finding fresh blood every two to three days or death, vampire bats will bite people, sometimes spreading their deadly viral disease of rabies.
My research into vampire bats fortuitously coincided with a look at the origins of Frankenstein and the Vampyre on the history podcast with Katie, focusing on Lord Byron's famous challenge to his literary assembly, "We will each write a ghost story." If I'm ever a participant in such a challenge, I've got dibs on Amazonian vampires.