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Tsunami Warning
Caused Panic in Costa Rica's
Pacific Coast
Thousands Without
Water After Truck Hits Watermain
Lorin Hollander,
Pianist, Speaker, Educator Coming To
Costa Rica
Thriving on Cattle
Blood, Vampire Bats
Proliferate |
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Thriving on Cattle
Blood, Vampire Bats
Proliferate
By Jeanna Bryner,
LiveScience.com
Vampire bats living in
Costa Rica are growing
in number as they are
sucking their blood
meals from cattle rather
than wild rainforest
mammals, a snack swap
based more on
accessibility than
taste.
A new bat-breath
analysis study,
published online in the
Journal of Comparative
Physiology B, reveals
how the conversion of
rainforests into farms
with livestock has
resulted in the
expansion of vampire bat
populations in Latin
America. Cow blood could
be the reason.
Farmers have observed
vampire bats attacking
cattle recently.
(Vampire bats only feed
on humans in rare
instances.)
To see if the farmers
were right about the
overall trend in bats'
new diets, Christian
Voigt of the Leibniz
Institute for Zoo and
Wildlife Research in
Berlin and colleagues
measured isotopes in
exhaled carbon dioxide
in both captive and wild
vampire bats.
“The potential victims
of vampires in Costa
Rica are either cattle
or rainforest mammals
such as tapirs and
peccaries," Voigt said.
The two animal groups
feed on different plants
with distinct levels of
carbon isotopes.
"Therefore, we expected
that the stable carbon
isotope signature in bat
breath would change
according to their
diet,” Voigt said.
The bat breath showed
the chemical marks of
cattle, indicating, the
authors say, that the
last blood meal of the
flying mammals almost
always was cattle.
The vampire bats don't
necessarily prefer
bovine blood, the
scientists say, but
cattle are held in
fenced-in open pastures,
making them and their
blood much more
accessible than that of
free-roaming rainforest
mammals.
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