Costa Rica is home to at least 210 species of mammals, more than half of which are bats. Which means that if you’re fortunate enough to live in or visit this tropical world, you’ll see bats when you watch the twilit sky. And this being the spooky time of the year, I thought it only proper to write about vampire bats. After all, they get much of the press when its Halloween.
Vampire Bats Are A Spooky Halloween Symbol
Thanks to the beloved actor Bela Lugosi and lots of silly, old-timey Hollywood movies, people think of vampire bats as scary, blood-sucking killers.
Despite all the Hollywood hype, vampire bats are very secretive and rather shy creatures. There are only three species of vampire bats and all are New World species. And we’re lucky enough to have all of them right here in Costa Rica. There’s only one, however, that feeds on the blood of livestock. The other two, the Hairy-legged vampire bat (Diphylla ecaudata spix) and the White-winged vampire bat (Diaemus youngi) prefer to feast on bird blood (especially chickens and guinea fowl.)
The common vampire bat (Desmodus rotunda) is the odd bloodsucker out here. It prefers to feast on livestock. Which of course, gets it in trouble with local farmers due to outbreaks of paralytic bovine rabies which generally occur twice per year in Costa Rica, Bat Conservation International reports. The Costa Rican government runs a program that eliminates vampire bats from problem areas when a rabies outbreak occurs, but the local people also take matters into their own hands.
This winds up to be an unfortunate situation because they wind up killing bats in caves or other roost sites or lacing bananas or other fruits with poison to kill fruit-eating bats. And that’s especially tragic because harmless and beneficial bat species are killed.
How vampire bats do what they do
This small creature (just under three inches to 31/2 inches) has specially adapted hind feet with long callused “thumbs” that help it grip the ground, enabling it to walk or run quickly in its search for food. The little reddish-brown to gray bats have larger eyes than other bats and a well-established sense of smell enhanced with heat sensors in their noses. The better to smell you with m’dear.
And in Costa Rica, wherever there’s livestock, there is the vampire bat. White-tailed deer, located in Costa Rica’s Guanacaste region, in the northern part of the country, are also on the menu. Using echolocation, the bat emits tiny and nearly imperceptible squeaks that bounce off the intended prey, making it easier to zero in on. When the bat finds its next meal it either lands on the animal, or on the ground close by. On cattle, vampire bats usually lap blood from the animals’ neck and they are next to impossible to shake off. Their tiny teeth are razor-sharp. So sharp, in fact, that the victim rarely feels the bite. Now the bat slices a tiny three-millimeter section of skin, and because they have an anticoagulant (which keeps the blood flowing) in their saliva, they can lap blood for as much as half an hour.
To make getting a meal even easier, a vampire bat’s tongue is grooved on the underside, functioning just like a straw to lap the blood. To stay healthy, these bats need to consume about 15 ml of blood daily. These winged fuzzies often return to the same animal every night, reopening the same wound.
Vampire bats care for their own
As soon as they are done with their meal, they return to their roost. If a member of the roost fails to score a meal, other members will regurgitate and share some of their own. During the day, vampire bats rest communally in hollow trees or unused wells, but at night, they prefer to roost in caves. Their colonies can be enormous, with thousands of individuals and they even share the roost with other bat species.
And female vampire bats are actually good mothers too, giving birth to one pup and feeding it regurgitated blood for three months, and helping them learn to hunt when they are five months old.
Which means vampire bats are nothing like those bloodthirsty killers portrayed in campy old movies.
Watch this vampire bat procure a meal in the video below.