Genetic adaptations have allowed the bloodthirsty mammal to survive on minimal calories

South American vampire bats are the only mammal in the world based solely on what zoologists call "blood-eating." But how do they survive on so few calories?

The answer is given by a study published in Science Advances, an online edition of the Nature group. The researchers compared the genome of the common vampire bat, Desmodus rotundus, with the genomes of 26 other bats and identified 13 genes that are missing or have ceased to function in vampires.

These adjustments have allowed the bloodthirsty mammal to eat large amounts of protein and iron and almost no fats or carbohydrates, according to the international research team.

Vampire bats are divided into three species that live exclusively in Central and South America and usually attack domestic or wild animals while they sleep. However, several cases of attacks on people have been reported, with some of the victims even suffering from rabies.

Bloodthirsty mammals are basically "living vampires," Michael Hiller of the Max Planck Institute for Molecular Cell Biology in Germany told the Associated Press.

No other mammal could live on so few calories. "Blood is a bad source of food," said Hannah Kim Frank, a specialist at Louisiana University in Tullein who did not participate in the study.

"It's really weird that vampire bats live exclusively on blood - they're really weird, even in the bat world."

The new study extends the findings of a previous study that identified three of the 13 gene losses.

"The new publication shows how different vampire bats are from even more closely related bats, which feed on fruit and nectar," said Kate Langwig of the Virginia Institute of Technology, who also did not participate in the study.

With a diet so low in calories, vampires need to be fed often. It is known from previous observations that well-fed vampires vomit a part of the meal and share it with the neighbors.

Vampire bats have a complex social life and remember who helped them in the past, Hiller said. This practice is not limited to relatives, he pointed out. "They just pay attention and remember," he said. "If you share your food with me I will reward you in the future."

And what better reward than a little vomiting of blood?

in.gr