|Image: JLplusAL via Flickr|
Common Vampire Bats have a whole host of adaptations to help them in their nefarious night-time deeds. The ability to fly is a great start. I know that I would personally be absolutely furious if I found something drinking my blood, so a little 10 cm long bat better be ready when I start swinging my own bat through the air like a madman. Or at least a very angry man.
Common Vampire Bats spend their days sleeping in dark places like caves, tree hollows, old wells and buildings (I'm sure derelict asylums built on ancient Indian burial grounds are favoured). All the scary, haunted, horror places. They live in colonies, sometimes with thousands of individuals, throughout South and Central America. They awaken at night. Time to feed.
So, let's journey with a Common Vampire Bat.
|Image via Wikipedia|
We use echolocation just as other bats do. This involves shrieking into the air and building up a picture of our surroundings based on the echoes that come back to us. I probably wouldn't call it "shrieking" if it was anything other than a Vampire Bat, but it is a Vampire Bat so... I'm not gonna say "squeaking", anyway.
The truth is, Vampire Bats don't have as good echolocation skills as many other bats, but they do have better eyesight to compensate. They can spot a promising host from over 100 metres away. Their hearing is even better, and the sound of breathing seems to be their main way of discovering prey.
We aren't overly choosy. Horses, cattle, dogs... humans. Any mammal will do so long as it's fast asleep and we can feed in peace. We have our preferences, but you don't get "Common" added to your name by being picky about who's blood you're willing to drink. Once you've decided to drink blood, well... that's half the battle, right?
|Image by Robertsphotos1 via Flickr|
In any case, we now reach our great, big, bottle of claret. We just have to open it up and enjoy. Luckily, our nose is armed with thermoreceptors that sense heat beneath the skin of our host. This is where the blood is, and where there is more heat there is more blood closer to the surface.
Once we pick our spot we prepare the area. Using our teeth to shave away the fur gives us access to the skin and ensures blood doesn't get clogged up all over the place. No need to cause a mess.
|Image via Wikimedia|
The red stuff flows and we inject our saliva into the wound. Sure, it adds insult to injury but it's nothing personal, it simply stops the blood from clotting and the blood vessels from constricting. We lap up our fill.
A Common Vampire Bat weighs about 57 grams (2 oz) but that can double in one half hour feed. The stomach immediately absorbs the blood plasma and takes it to the kidneys, leaving the nutritious red blood cells behind. Two minutes after they start feeding they already pass out the plasma through urine, making space for yet more blood. This stuff just goes right through me!
When we're finished, we leap into the air and fly into the night. Within two hours of leaving the roost we are back, resting and digesting.
The whole process will be repeated tomorrow, and if not tomorrow then the day after. We Vampire Bats need to eat every two days and once we find a good host we return to it night after night. Our urine serves as a marker to other Vampire Bats and we will chase away anyone who tries to feed on our property. It's a good thing we are so family orientated, then. Oh yes, everyone hears about the blood and the biting, but what about the bonding?
Common Vampire Bats live in a harem system, with one male defending numerous females. The females will rarely mate with any other male even if they get an opportunity to. Sometimes several males will defend one roost, in which case the alpha male will father at least half the offspring, the second male will have the second most and so on down the ranks.
|Image: Phil Myers|
Female Common Vampire Bats have very strong bonds. They groom each other and look after and even feed each others young. If a mother dies, another one will adopt the orphan. Vampire Bats are thought to be the only bats to do this.
They sometimes even share food. A hungry Vampire can beg for food from a friend and receive some tasty regurgitated blood. Hopefully, she will remember this and return the favour if the time comes.
This cooperation helps the whole colony combat starvation, since getting a blood meal every day or two can't always be easy.
Next time you see, hear or... feel a Common Vampire Bat, think not of just her vampiric ways. Think also of that same belly-full of blood as it is lovingly regurgitated into the throats of her children and sistren. Surely, such an image of caring and sharing can only bring warmth to one's heart. And a nice, warm heart is something they'll appreciate next time they see you.
|Image via Wikipedia|