The Vampire Bat!

Ed. note- This is reprinted from the 2003 BooNews.  Enjoy!

Vampire bats. The very name may send chills down your spine. Creepy furry things with wings that hang upside down from dank, dark ceilinged caverns. You may start with fear at the mere thought of dark, silent, flapping wings, sharp, biting fangs and the strong sucking of your scarlet pulsating blood.

Okay. Reality check. Does this look like the face of a villain? This little fellow, Desmondus rotundus is one of the microbat family, one family of the only mammals on Earth that can truly fly! They weigh about one ounce with a body the size of an adults thumb. They are up to 2-3/4” long and have up to an 8” wingspan. They are really kind of cute little critters.

There are only three species of vampire in Central and South America. They live in structured colonies of usually one hundred bats but possibly as many as one thousand; the females separate from the males so that the males can protect their territories. They have close social bonds, often teaming up into pairs in a sort of buddy system, This is of great importance.

If for some reason a bat cannot leave the cave to eat, other bats will return to the cave and regurgitate their meal for the hungry one. A bat can starve to death in two to three days. Vampire bats eat two tablespoons of blood per day. Not exactly enough to drain a human body is it now?

Bats normally live to nine years in the wild but can live to twenty years in captivity. They mate all year, but usually only have one offspring per year. Gestation is six to eight months.

Everyone knows that bats get around using echolocation, (bouncing ultra-high frequency sound from their noses off objects to “see” or rather hear where they are.) But one of the very different things about vampire bats, other than their feeding habits, is that only the common vampire bat is truly able to maneuver on the ground as well as in the air. Vampires can move in all directions, just like a spider. And instead of taking of in flight from the ground they actually launch themselves by extending its hind knees, launching forward and using its powerful pectoral muscles and forelimbs. The jump takes all of 30 milliseconds and launches the bat four feet into the air!

They locate their prey using a combination of smell, sound, echolocation and possibly heat. They do not suck the blood from their prey, rather they make a small incision and lap up the blood. According to John D. Altringham in his 1996 Bats, Biology and Behavior, “They have heat sensors on their noseleaf for locating capillary-rich areas of the skin; modified canines for fur clipping; long sharp incisors for painlessly opening a wound; anticoagulants to prevent clotting; and a grooved tongue to help move blood rapidly to the mouth.” He adds that while a bat may eat up to 60% of its body weight in blood, it needs only red blood cells and will begin excreting plasma before it’s meal is over. It has a specialized stomach and kidneys to do the job quickly.

A recent and possibly life saving discovery has thrilled the scientific community. The saliva of a vampire bat may one day give some stroke sufferers a better chance at survival. In a study published by Stroke: Journal of American Heart Association the saliva contains a potent clot busting substance that could help more than existing medications. This bat compound, an enzyme known as desmoteplase or DSPA was identified by scientist more than 10 years ago. The same anticoagulant the bat uses to feed also makes it a candidate for treating strokes. The current clot buster is rt-PA and when exposed to fibrin (which makes up blood clots) it causes the fibrin to break down. Bad news? It can also damage brain tissue. For this reason it is only used within 3 hours of stroke and only in a small percentage of patients. Animal testing so far indicates that DSPA also attacks fibrin without damaging brain tissue. The US is calling for further research, but human trials have begun in Asia, Europe and Australia.

Western literature has embraced vampire bat blood thirsty, neck-slashing artery-sucking folklore. We have added the allure of the transformation of vampire man into vampire bat. Interestingly, European folklore of vampires did not include the vampire bat. This was probably because they were not indigenous to the area. Some Gypsy folklore involved the vampire bat but in a benign role. The bones were carried in a bag as a good luck talisman.

There are tales of human hosts to vampire bats. In 1939 a Dr. William Farabee claims to have awakened in the morning to find that a vampire during the night had gouged a small piece from the tip of his nose and had feasted while he slept as it was still bleeding slightly.

As you can see vampires are not vicious, nasty little beasties, they are just fragile fellow mammals striving to survive. Next time they give you the creeps– think again