Saturday, November 01, 2008

Blood Sucking Vampire Bats Sing Duets
This article is pretty cool, especially because it's Halloween. When you think of friendly, family oriented animals, vampire bats probably do not spring immediately to mind. However, new research shows that vampire bats may sing coordinated duets with each other. In this article, researchers explain how singing has been recorded in other species, and between mother-pup pairs in other bat species, but never before between adult bats. New research shows that adult White-winged vampire bats may exhibit this behavior. 18 white-winged bats were tested in the experiment. It was found that when chickens, a popular source of blood for the bats, were brought near them, the bats became very vocal. It was also found that when the lights were turned off, the bats started calling out. Surrounding bats responded to the initial caller within 1/4 of a second after the first call. Each bat was also found to have it's own unique call that other bats could identify it by. The scientists conducting the test believes the calls could be a mechanism for bats to find one another when seperated, as well as being a way for a bat to convey how it is feeling. While this group oriented behavior may seem strange in an animal that has so many negative stereotypes, it's interesting to note that vampire bats are one of the few species known to exhibit reciprocal alturism, meaning they are known to share food with more unsuccessful members of its group.

Edit 11/4
According to, reciprocal altruism occurs when "when the actor acts altruistically in expectation of having the same done in return at a later time. " So, the bat will help out less successful group members, knowing that this increases his chances of being helped in the future. Not many other animals besides humans are known to display alturism. One form of alturism, kin selection, where an animal will help its close relatives survive at a cost to itself, is shown in the Kenyan Bee-Eating bird. This bird will wait until it is older to produce its own young, instead helping its older family members raise their chicks. (This information can be found here.)
In regard to the song the bats produce, they are NOT on the same frequency as echolocation, since they are at least partially audible by humans. As to what they are singing about, or why they are doing it, that hasn't been determined yet. One theory is that it helps identify who belongs in the same group. This goes back to the reciprocal alturism. Each bat's individual song may identify it to others, so a bat will know if it's his group mate who's asking for a snack, or just some random individual that he should ignore.
Just as a side note, does everyone know that vampire bats don't actually drink enough blood to harm most large mammals? It's more like a bad mosquito bite. The real danger lies in the diseases they can pass on, such as rabies.

-Corinne Delisle (7)


At 1:06 PM, Anonymous Anonymous said...

Aw wow I was always wearing of vampire bats, I had no idea they share their food with their unsuccesful others. They seem to be more social than people give them credit for. This was a good article maybe now Vampire Bats wont be so scary to some!

At 1:07 PM, Anonymous Anonymous said...

Aw wow I was always wearing of vampire bats, I had no idea they share their food with their unsuccesful others. They seem to be more social than people give them credit for. This was a good article maybe now Vampire Bats wont be so scary to some!

Mia DiFabbio

At 1:32 AM, Blogger PWH said...

Very interesting...I wonder if this singing is just a signal for food being nearby. I also wonder why only duets are sung between mothers and pups vs. fathers and pups?

-Joanne Philippeaux

At 8:58 AM, Blogger PWH said...

This is an interesting find. It seems that the bats vocalize to let other members of their group know that a food source is present. Are there any other benefits to this vocalization method? I wonder if vampire bats hunt in groups or alone? I also wonder if they could use this form of vocalization to let other bats in their group know where food is located. Is this singing that the bats produce in a frequency that a human could hear or is it a product of an echolocation type frequency?

Posted by: Lindsay Goodyear

At 10:22 AM, Blogger PWH said...

This comment has been removed by the author.

At 10:23 AM, Blogger PWH said...

Do you know of any other animals that use reciprocal altruism? Humans use it a great deal among family members, but I wonder if any other animals do.

Jimmy Sullivan

At 12:56 PM, Anonymous Anonymous said...

Very interesting that they sing duets together. I imagined that they communicatedm but not in this sort of fashion.

Duy Nguyen

At 2:29 PM, Blogger PWH said...

I guess vampire bats could be classified as a social animals through both their communication behavior and group hunting techniques. I'm sure eventually some researchers will do some work on the actual songs of the bats and what the definite meaning behind them is. Who knows they might be as developed as some song birds are.

Patrick Salome

At 6:52 PM, Anonymous Anonymous said...

This is very interested... I always assumed that bats communicated using sound somehow... Since they are nuctornal animals, sound would be very useful in communicating with one another... I would imagine that bats use vocal sounds more than most animals to communicate the location of food or if there are predators around.

Brena Sena

At 6:53 PM, Blogger PWH said...

Interesting article!
Is the fact that they are reciprocal altruists possibly due to the fact that they do communicate to each other through song? also, many animals communicate to each other, the fact that they do so as well, especially when it is dark, seems like it would make sense. Could the singing due to the presence of a chicken be due to the fact that they are communicating the location of prey?

Ahmed Sandakli

At 6:56 PM, Blogger PWH said...

I wonder if the fact that these bats use reciprocal altruism that they developed this kind of communication.

Charles Scondras

At 8:38 PM, Anonymous Anonymous said...

I think its awesome but I have to say that I'm not at all surprised.
People have stereotyped animals in the past. A few examples: not only does the bible not once refer to dogs as man's best friend, it is often used as a derogatory term. In Arabic, calling someone a dog is also a common insult. Therefore, I don't find it hard at all to believe that bats may also be demonized and negatively stereotyped.
What I do wonder, though, is whether or not discoveries such as this would lead to bats becoming household pets- now that would be cool! (kind of.... I guess....)

-Noam Pelleg

At 9:16 PM, Anonymous Anonymous said...

I think it is quite interesting that bats actually make sure to give food to the bats that weren't able to obtain food. I was wondering have they found out if they do these duets in other aspects of their lives like mating?

- Debbie Theodat

At 11:40 PM, Blogger Dan said...

That's an interesting article. I can actually found the most interesting thing to be that the bats helped other less successful bats with food. You mentioned that the bats calling also conveyed how they were feeling, is it mentioned if there are any benefits to this?

~Dan Hong

At 11:44 PM, Anonymous Anonymous said...

Very interesting. Did the article mention how the bats live socially. It is very interseting that they would share food with the unsuccesful bats. I wonder what survival advantage if any does this give the bats who find the food?

Alex Pavidapha

At 11:56 PM, Anonymous Anonymous said...

This is really interesting! Although, my main question was (and according to a lot of other posters)is why do bats help the unsuccessful bats? Don't they want to fend for themselves? Also, why is it only between the mothers and pups -are they closer to each other? It's kind of cute that they sing together, it makes them less intimidating!

-Alyson Paige

At 12:17 AM, Blogger PWH said...

This is really an interesting article. I had no idea that bats can communicate like birds. I would like to know more about the reciprocal altruism behavior. What benefits the more successful bats from helping less successful bats?



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