|
 ANIMALS
Vampires: The Legend Continues
BY STEVE WING,
General Curator
I am a person who loves and respects all
creatures on our planet. I think
warthogs are beautiful, goats don’t smell, and the bray of a donkey is
music to my ears. I even think there is a place for leeches and
mosquitoes
(where that is I haven’t found out yet!).
But, other than making a good horror
story, what good can I say about the lowly vampire bat (Desmodus
rotundus)? Vampires have long been the stuff that legends are made of.
While some folklore is based in
reality, many myths surround this diminutive creature.
Vampire bats do not come from or live in
Romania. And they are NOT found in the United States. They are a New
World tropical species ranging from Mexico south to Argentina. They
mainly inhabit caves, but are also found in hollow trees, mine shafts
and abandoned buildings.
And unlike the giant vampire bats we see
in movies, true vampires are very small, about the size of your thumb.
The grayishbrown bats have a wingspan of 8 inches and they weigh about
40 grams. In the wild they live to be 9-12 years old, but can easily
live to be 20 years or older in zoos. They generally have one pup a year
after a gestation of about 7 months. They live in colonies of 20-100
individuals, but can number as low as 6 or as many as 2000!
 The common vampire bat is the only bat
that can walk and hop on the ground and take off vertically.
It is true that vampire bats drink blood.
No, they don’t suck blood like in the movies, but they do make a
small, sharp incision in an area of the skin where blood vessels are
near the surface. Most of the time the animal being bitten does not even
feel the bite. An anticoagulant in the vampires’ saliva delays the blood
from clotting, allowing the bat to lap up the blood. The amount of blood
taken by a single bat is not great and generally does not affect the
sleeping animal. The real danger of vampire bites lies in the diseases
and infections that may result. Rabies is a common disease transmitted
by vampire bats. This occasionally has a detrimental effect on the
cattle and horses that cohabitate with us. And yes, vampires do
occasionally
feed upon human beings.
Think that vampire bats have no redeeming
value? Think again! Scientists have isolated an enzyme from the saliva
of the vampire bat. This enzyme, named desmoteplase after the vampire’s
scientific name, has
been developed into a bloodthinning drug that helps prevent strokes and
heart attacks in humans. Clinical
studies have indicated that desmoteplase could improve blood flow in the
damaged area of the brain if it was given within nine hours after the
onset of stroke symptoms. Although the drug is now made synthetically,
we would not have discovered it without the vampire bat!
Steve Wing is the
chair of the AZA Bat Advisory Group, which directs breeding programs and
in-situ conservation efforts worldwide. He also maintains the North
American studbook for the Rodrigues fruit bat.
photos courtesy of Houston Zoo, Inc.
This article was originally
published in the Spring 2006 issue of Trunkline magazine. |
