Scientists have figured out why vampire bats are the only mammals* that can survive on a diet of just 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 have helped them adapt to a blood diet rich in iron and protein but with minimal fats or carbohydrates*, researchers reported on Friday in the journal Science Advances.
The bats live in South and Central America and are basically “living Draculas,” said Max Planck Institute Professor and co-author Michael Hiller.
About eight centimetres long with a wingspan of 18 centimetres, the bats bite and then 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 1400 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 Tulane University bat researcher Dr Hannah Kim Frank, 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.”
Some other creatures also have a taste for blood, including mosquitoes, bedbugs*, leeches and fleas.
The latest work expands upon research by another team that pinpointed* three of the 13 gene losses.
“The new paper shows how different vampire bats are from even other closely related bats, which eat nectar and fruit,” said Virginia Tech Assistant Professor Kate Langwig, a bat researcher who had no role in the study.
With such a low-calorie diet, vampire bats can’t go long without a meal. In a pinch, well-fed ones will regurgitate* their food to share with a starving neighbour. They seem to keep track of who has helped them in the past, said Professor Hiller, noting that vampire bats have complex social relationships.
“It’s not a kin* thing,” said Tulane University’s Dr Frank. “They just notice and remember: ‘You’re a good sharer, I will reward you’.”
GLOSSARY
- mammals: warm-blooded vertebrates like dogs and humans that birth babies and feed young with milk
- genome: any organism’s complete set of genetic information
- carbohydrates: the sugars, starches and fibres in fruits, grains, vegetables and milk products
- livestock: farm animals like cows and sheep that are kept or traded for income
- nectar: sweet liquid produced by flowers, which bees and other insects collect
- pollen: powder produced by the male part of a flower, that causes the female part of the same type of flower to produce seeds
- bedbug: very small, wingless bug that bites people at night, often found in unclean beds
- pinpointed: identified, discovered, located, detected
- regurgitate: act of bringing swallowed food back up to the mouth
- kin: group with common ancestry, family, relatives
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QUICK QUIZ
- How many species of bat are there?
- A blood diet is rich in what two features?
- How many genes are missing or defunct (no longer in use) in vampire bats?
- What are four other creatures that also have a taste for blood?
- How do vampire bats help each other if one of them is starving?
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CLASSROOM ACTIVITIES
1. Vampire bats
Complete the Venn diagram below classifying information about vampire bats and other bat species mentioned in the Kids News article.
Time: allow 20 minutes to complete this activity
Curriculum Links: English; Science; Critical and Creative Thinking
2. Extension
“You’re a good sharer, I will reward you” is the behaviour vampire bats exhibit towards each other. When has this applied in your life? Give an example and share with a friend.
Time: allow five minutes to complete this activity
Curriculum Links: English; Personal and Social
VCOP ACTIVITY
Read with Kung Fu punctuation
Pair up with the article between you and stand up to make it easy to demonstrate your Kung Fu punctuation.
Practise reading one sentence at a time. Now read it again, while acting out the punctuation as you read.
Read and act three sentences before swapping with your partner.
Take two turns each.
Now ask your partner to read a sentence out loud while you try and act out the punctuation. Can you keep up? Swap over?
Try acting out two sentences – are you laughing yet?