Bats feast on human blood after habitat invaded
BRAZIL: Vampire bats have been found doing in reality what was previously thought to be confined to the imaginations of horror writers: sucking human blood.
The discovery has prompted fears that the bats could, like Count Dracula himself, become a mortal threat to people – albeit as transmitters of fatal disease rather than by draining young women of their blood from the neck and turning them into the undead.
Scientists from the Federal University of Pernambuco in Recife, Brazil analysed 70 samples of faeces from a colony of hairy-legged vampire bats known as Diphylla ecaudata, living in a cave in Catimbau National Park in the northeast of the country.
Enrico Bernard and his team found traces of human blood in three out of 15 samples.
‘‘We were quite surprised. This species isn’t adapted to feed on the blood of mammals.’’
The creatures in the study, first published in the journal Acta Chiropterologica, are one of three species of vampire bats that feed only on blood.
Their preferred diet is the blood of large birds, which they extract at night by puncturing their prey’s skin with sharp incisors and then lapping up around a spoonful of the fluid.
An anti-coagulant in the bats’ saliva prevents the blood from clotting too quickly.
They are adapted to process fatrich bird blood, not the thicker, high-protein blood of mammals.
In previous experiments the vampire bats have starved to death rather than eat when the only blood available to them was from pigs and goats.
However, Bernard and his team believe that human encroachment on the bats’ habitat and the depletion of their favoured prey as a result of hunting and deforestation may be driving them to try a new diet.
Humans living in the park are probably being bitten while sleeping outside in hammocks, or the bats are entering bedrooms through holes in windows and roofs.
This is a concern because it could lead to the spread of serious disease.
Vampire bats are transmitter of rabies.
They have also been known to carry the hantavirus, which can lead to a severe, sometimes fatal respiratory disease in humans, Daniel Becker, of the University of Georgia in the United States, who is also studying vampire bats, told the New Scientist. – The Times a leading