WASHINGTON — Scientists have discovered why vampire bats are the only mammals that can survive on a blood-only diet.
They compared the genome of common vampire bats to 26 other bat species and identified 13 missing or no longer functioning genes in vampire bats. Over the years, these genetic adjustments have helped them adapt to a blood diet high in iron and protein but with minimal fat or carbohydrates, the researchers reported Friday in the journal Science Advances.
Bats live in South and Central America and are essentially “living Draculas”, said co-author Michael Hiller of the Max Planck Institute in Germany. About 3 inches (8 centimeters) long with a wingspan of 7 inches (18 centimeters), the bats bite and lap the blood of livestock or other animals at night.
Most mammals could not survive on a low-calorie, blood-based liquid diet. Only three species of vampires out of the 1,400 types of bats can do this – the others mainly eat 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 weird and amazing that vampire bats can survive on blood – they’re really weird, even among bats.”
Some other creatures also taste like blood, including mosquitoes, bed bugs, leeches, and fleas.
The latest work extends the research of another team that identified three of the 13 gene losses.
“The new paper shows how different vampire bats are from other, closely related, nectar- and fruit-eating bats,” said Kate Langwig, a bat researcher at Virginia Tech, who doesn’t. played no role in the study.
With such a low-calorie diet, vampire bats can’t go long without a meal. In a pinch, the well-fed will regurgitate their food to share with a hungry neighbor. They seem to keep track of who has helped them in the past, Hiller said, noting that vampire bats have complex social relationships.
“It’s not about kinship,” Frank of Tulane said. “They just notice and remember: you are a good sharer, I will reward you.”
The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute Department of Science Education. The AP is solely responsible for all content.