Scientists figure out how vampire bats got a taste for blood

They compared the genome of common vampire bats to 26 other bat species and identified 13 genes that are missing or no longer work in vampire bats. Over the years, those gene tweaks helped them adapt to a blood diet rich in iron and protein but with minimal fats or carbohydrates, the researchers reported Friday in the journal Science Advances.

The bats live in South and Central America and are basically “living Draculas,” said co-author Michael Hiller of Germany’s Max Planck Institute. About 3 inches (8 centimeters) long with a wingspan of 7 inches (18 centimeters), the bats bite and than lap up blood from livestock or other animals at night.

Most mammals couldn’t survive on a low-calorie liquid diet of blood. Only three vampire species of the 1,400 kinds of bats can do that — the others eat mostly insects, fruit, nectar, pollen or meat, such as small frogs and fish.

“Blood is a terrible food source,” said Hannah Kim Frank, a bat researcher at Tulane University, who was not involved in the study. “It’s totally bizarre and amazing that vampire bats can survive on blood — they are really weird, even among bats.”