Vampire bats are extremely strange animals, and it really makes very little sense for a flying fruit-eater to evolve into sucking the blood from other mammals. There are lots of unanswered questions about the vampire bats, but a recently published paper has looked at the genetics of the vampire bats to find out why they are feeding on blood.
A common vampire bat in Sangayan Island, Paracas National Reserve, Departamento Ica, Peru. Image by Wikimedia Commons user Acatenazzi, posted with the Creative Commons Attribution-Share Alike 3.0 Unported license.
The biology of the vampire bats
There are currently three living species of vampire bats: the common vampire bat (Desmodus rotundus), which is shown in the picture above, the hairy-legged vampire bat (Diphylla ecaudata), and the white-winged vampire bat (Diaemus youngi). All three species are found in the Americas, and are found in areas in Mexico, Chile, Uruguay, Argentina and Brazil.
The vampire bats feeds mainly on the blood of livestock and other mammals during the night, and uses razor-sharp teeth to cut open the skin of the prey and suck blood out of It by using its tongue. This is their primary food, and most vampire bats never really eat anything else than blood their entire life!
Most vampire bats carry a lot of different diseases such as rabies, and are considered a pest in most places because of this. While only 6 % of the vampire bats have rabies, they are known to have transmitted the disease to both pets and humans, so it is best to stay away from them, and seek medical attention if you get bitten. They don’t really feed on humans, but those infected with rabies are obviously pretty weakened, which might lead them to trying to feed on anything they can.
Image by Wikimedia Commons user Ltshears, posted with the Creative Commons Attribution-Share Alike 3.0 Unported license.
The species have a common ancestor
Feeding only on blood is obviously a very unique trait, so not surprisingly scientists believe that this evolutionary trait only evolved once in a common ancestor of all three species. Despite this the three species are very genetically different, and are even put in three different genera, where they are all alone. They all belong to the subfamily Desmodontinae in the family Phyllostomidae that includes all leaf-nosed bats, which are all bats that are found in the Americas.
How come the vampire bats drink blood?
I briefly mentioned how strange it is that vampire bats do drink blood, and for a long time it has baffled scientists that they are able to live purely off this diet. There are a few problems with eating only blood, such as:
- Blood has a high protein concentration (93 % of blood is protein), and almost no carbohydrates or vitamins. This should be a harmful diet just based on the sheer lack of vitamins! Protein poisoning is also a serious threat.
- There are lots of blood-borne diseases that will infect animals that come into contact with the blood, so how do the bats survive this?
- The huge amount of liquid should be dangerous for the kidneys.
- Blood is high in iron, which should lead to iron poisoning.
So how do they deal with all of this? I won’t lie and say that we know all the answers, but a research team from University of Copenhagen in Denmark has taken a look at the hologenome of the bats, and at least made some nice progress towards these questions.
A hologenome is the entire set of genes of an organism, including all microbial genetics found within the organism. This means that the hologenome not only looks at the genes of the organism itself, but also all parasites, gut bacteria and neutral microorganisms in the body. The researchers obtained this by collecting guano (scat) from the vampire bats, and tested it against the hologenome of other non-vampire bats.
Image by Wikimedia Commons users Sreejithk2000, posted with the Creative Commons Attribution-Share Alike 2.5 Generic license.
The crazy gut microbes of the vampire bats
The first thing that the research team found out was that the gut microbes of the vampire bats was a lot more crazy than the other bats, and includes many bacterial species that cause disease is most other mammals. In fact, they found over 200 disease-bearing microbes in the gut biome of the vampire bats!
This is an important discovery, because it lead to the theory that the ability to live of blood is closely related to the gut microbiome! The scientists believe that these microorganisms are helping out with some of the unique problems that arise when you only feed on blood, meaning that the same organisms that can cause disease and death in most mammals actually serve an important function for the vampire bats!
Other interesting discoveries about the vampire bats
The same study also obviously looked at the genome of the vampire bats themselves, and what the found is that the transposon gene called MULE-MuDR is found in over twice the amount in vampire bats compared to other bats. This type of gene is able to multiply and move around on the DNA on its own, and are often also called “jumping genes”. While the exact function of the gene is still unclear, it was found in areas that were responsible for immune response, viral defense and metabolism, so the researchers believe that it is playing a part in the process of controlling the problems related to the consumption of all that blood.
Thanks for reading
I hope you enjoyed the post, and as always, thank you very much for taking the time to check it out! If you want to learn more, then check out the paper that was published, or check out the article by BBC that also interviews the lead author.
About @valth
Hey, I'm @valth - the author of this post. I love to write about nature, biology, animals, nature conservation, ecology and other related branches of science, and I occasionally write about my life, about Steem or about random stuff as well. I'm trying my best to write at least one post every day, so make sure to give me a follow if you enjoy my content and want to see more of it.
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I absolutely love Bats, especially at dusk watching them seemingly randomly flittering around catching insects, especially near water. In the UK, they are considered pests, not because of rabies which luckily we have eradicated here, but because they are all protected species by law. Ask anyone wanting to build a new home, or do a barn conversion. Part of planning law involves having a survey done to check that the Bat's natural habitat isn't being disturbed, they cost the UK building industry millions!!
Another great article, you write so readable....
PS "Blood has a high protein concentration (93 % of blood is protein), and almost no carbohydrates or proteins" typo ? lol ;-)
Hi @nathen007. Thanks for pointing out the typo! This means two types in as many posts now, so time to get a bit stricter with my proof-reading from now on. It's supposed to say carbohydrates and vitamins :)
Ouch, I can see why that is annoying. I've heard of some people who have had some of the same problems here in Norway, but we don't really need to have a survey done unless there's a threatened population in the area, so it's not really likely to cause much trouble.
Its strange that some vampire blood never really eat anything else than blood during their entire life and other strange thing is they carry a lot of different diseases
Yeah, it is strange indeed!
I wonder how people control these bats (since its like a pest to them) without endangering thier species. Sure vampire bats have purpose in the ecosystem.
There are many species that are considered pests, but that are still easily able to not get endangered, such as rats and many species of birds. I don't know the speficics of how people hunt/kill the vampire bats, but all three species are considered Least Concern by the IUCN Red List, so they are at least doing fine for the moment.
Thanks for taking the time to comment, @s3carlo!
I have heard of vampire bats but never seriously thought about the problems that can arise with blood light...So thanks for shedding some light.
And I guess Dracula is just a myth!!!
Same here; I've read about them in the past, but I never really stopped to think how problematic it would be to live entirely on blood. But it does of course make a lot of sense that they need some specialization to be able to do this when I think about it.
Never really thought of someone like this. Most of the bats here (in the Philippines) are all fruit-eating. It would be terrifying to know if these bats exist here. 😂
Luckily for you these are only found in South/Middle-America ;)
Oh they are scary and have small mouth.I have heard that these vampire bats have heat sensors
Yeah, the vampire bats do in fact have "heat sensors", or maybe precise infrared sensing :) It's really cool, but I decided against including it in today's article to keep it at a reasonable length, but maybe I'll make a post about this feature in the future ;)
I figured they ate a lot of insects too. Seems like the mammals could hide from them and manage to kill some of them. I'd sure try and kill a bat that was trying to feed off of me. lol
Yeah, there are many bats that eat insects, but the vampire bats strictly feed on blood.
Haha, that's a good point, but keep in mind that they appear during the night and feed on cattle and other large mammals that might not really care too much about being bitten.
Oh yeah there's not much a big old cow could do. That's gotta really suck for the cows. A cow vs a bat would be like a bear trying to fight a greyhound or whipet. lol I bet a bat is 100-1000 times faster than a cow but maybe only 10 times faster than me so it better feast on the cattle and livestock and not me. lol
Yeah, exactly. They have no way to get rid of the bats, other than just wait for them to suck enough blood to not be hungry anymore.
Strange features of vampire bats, heard about these bats in old fiction story. So they are just like vampire who eat blood only. My fear of vat increased after reading your post.
Yep, pretty much! Luckily they are only found in a small part in Middle-America, so no need to worry about them in other places in the world :)
All the best to people residing in the area of vampire bats (Middle-America). Keep sharing @valth
I have no plans on stopping anytime soon ;) hehe
V v v informative post......i had no idea before that bats survive on blood (only proteins,no carbs,no fats) only and how the crazy gut microbes are playing their role in their survival.......SO DRACULAS REALLY EXIST!!!😅😂
Keep in mind that it's only a few species, not all :)
Yeah, the vampires have been heavily inspired by these bats, and these guys have spread so much fear in all of history :)
I love bats but i hadn't research this thing that you had research @valth. Nice research @valth i hope you will found more new rear animal research.
Thanks :)
Welcome @valth bro
And keep on researching
I had follow you for more information that u will research
Thats why I like nature and biology, people always discover new things about the planet or animals which you would never stop to think about.... Well at least I wouldn't... Nice that people do, interesting read! Thanks
Yeah, it's really cool to think about the fact that we find new discoveries every single day! I'm glad you liked it :)
Its really a weared animal. You are the best. You share an amazing knowledge every time. What I seek from your posts is really a new thing to me. I am very thankful to you 👍🏻
Yeah, they are super weird animals :P hehe
Thanks!
Wow!!! This is very well detailed and educative. I know bats are nocturnal creatures but I didn't have an idea of a Vampire Bat. There are somethings that can't be totally explained, same goes with how Vampire Bats survive only on blood diet because it's really strange regardless of the latest discovery of the guts microbes found from the University of Denmark. Thanks for sharing this discovery @vaith
Thanks for the kind words. I'm glad you learned something new today :)
Found your post interesting to read.
I can't wait to see your post soon. Good Luck with the upcoming update.This article is really very interesting educative and effective.
Please stop making copy/paste template comments...As they are so easy to catch....You will get flagged.
Its disgraceful to the author who might have spent hours working on the post... Least you could do is spend some time reading the post and understand what the author is trying to convey.
Thanks for pointing it out, @xabi :) He even upvoted his comment to get more exposure..
Thanks @valth for sharing such a informative post,
Every post you bring a lot of knowlegde,you are doing great job,
Keep sharing,
Have a blessed life @valth
Stop spamming and generic bullshit..😡😡😡
Thanks :)
well i feel scare
They are not really dangerous to humans, except for the ones with rabies.
still it is wanderfull post
Thanks, I'm glad you think so :)
well.........so beautiful nature..........keep it up......
Stop spamming..😡😡😡
Nice work @xabi, its really annoying. Just go through the post, is that too much. Stop spamming!!!
To be honest i dont like bats because they Feed on blood, they carry disease. They are real vampires
Well, that's true. It's best not to get bitten by them!
I have a wonderful post is an image If You want to check i ll be very happy
once again a great and full of interest and informative post sir @valthy
Thank you :)
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I can't do much about the political situation in Nepal, unfortunately :(