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Vampire Origins
NICK HAWKINS/NATUREPL.COM
LOW-CALORIE LIQUID: Vampire bats must drink 1.4 times their weight in blood each day to get enough nutrients and calories to survive.
Vampire bats are the only mammals that survive entirely by feasting on blood. This red liquid is rich in the metal iron (Fe) and protein. But it’s low in other nutrients, such as fats and carbohydrates, that mammals need to live.
A team of scientists wanted to know how vampire bats came to survive on such an odd diet. The group compared the genetic makeup of the common vampire bat with that of 28 other bats that don’t drink blood. The researchers discovered 13 genes, or units of hereditary material, that no longer work in vampire bats. Some of these broken genes aren’t a defect but an adaptation, says Michael Hiller, an evolutionary biologist at the Max Planck Institute in Germany. Without these genes, the bats gained new abilities. For example, they are able to conserve the sugar in their body and process high amounts of iron.
Check out some other creatures that feed on blood.
SHUTTERSTOCK.COM
MOSQUITO
Even though mosquitoes are one of the world’s most notorious blood suckers, it’s only female mosquitoes that seek out blood meals. They need the nutrients to produce their eggs.
PETE OXFORD/NATUREPL.COM
VAMPIRE GROUND-FINCH
When foods like seeds and insects are scarce, this Galápagos Islands bird will use its razor-sharp beak to peck at the skin of large seabirds and feed on their blood.
LAMPREY
This eel-shaped fish has a circular mouth lined with rings of teeth. The lamprey is able to latch onto unsuspecting prey and stay attached for weeks as it feeds off blood and tissues.