by Carl Zimmer | Phenomena
Millions of years ago, some bats gave up their old habits of hunting for insects and tried something new: drinking blood. These creatures evolved into today’s vampire bats, and it’s mind-boggling to explore all the ways that they evolved to make the most of their sanguine meal.
A lot of the adaptations are easy enough to see with the naked eye. Vampire bats have Dracula-style teeth, for example, which they use to puncture the tough hide of cows. When they open up a crater-shaped wound, they dip in their long tongue, which contains two straw-shaped ducts that take up the blood.
Finding these prey has led to another remarkable adaptation that you can see–at least if you’re a scientist who studies how vampire bats move. Like other bats, they can fly, but on top of that, they can also walk and, yes, even gallop. Here is a video of a running vampire bat made by Dan Riskin (see this Loom post for details). Of the 1200 or so species of bats, vampire bats are among the very few that can move quickly on the ground.
But vampire bats have many other adaptations for drinking blood that are invisible. They use their combined senses–long-range vision, a sharp sense of smell, acute hearing, and echolocation–to find their victims. In their noses, they even have heat-sensitive pits that detect the heat of warm-blooded animals. Once they land on an animal, they apply those pits to the skin to locate capillaries full of hot blood close to the surface.
When vampire bats dip their tongue into a wound, they don’t just draw out blood. They also put their saliva into their victim. And in this liquid are still more invisible adaptations for a blood-feeding life. Vampire bats, you see, are venomous.
This may sound odd. That’s because we usually think of venom as a chemical an animal sticks in your body to cause you pain or death. But biologists define venom more broadly than that: it’s a secretion produced in a specialized gland in an animal, which is delivered to another animal by inflicting a wound, where it can disrupt its victim’s physiology.
Snake venom, the sort we’re all most familiar with, can disrupt physiology to the point of death. And it does so in several ways–jamming neurons, for example, or causing tissue to rot. But other animals that don’t set out to kill their victims also produce venom. Vampire bats, for example, don’t want eat a whole cow. They just want to take a sip.
Unfortunately, drinking blood has some drawbacks. Vertebrates come equipped with lots of molecules and cells that plug up wounds. As soon as they sense even a tiny tear in a blood vessel, they start making clots to staunch the flow.
Vampire bats use venom to keep the blood flowing. In a new paper with a title worth quoting in full–“Dracula’s Children: Molecular Evolution of Vampire Bat Venom”–an international team of scientists explore the molecules that vampire bats use to subvert blood’s defenses.
What’s most striking about vampire bat venom is how it goes after its victim from so many directions. Blood clots develop through a series of reactions that involve a chain of enzymes. Vampire bats produce different proteins to go after different enzymes in that chain. Platelets, which are cell fragments, also clump around wounds to help heal wounds. Vampire bats make separate compounds that attacks platelets.
Read the full article at: nationalgeographic.com
Real-Life ’Vampire’ Addicted to Blood, Doctors Claim
"The Vampire Tarot" by Robert M. Place
Serbian village puts out vampire warning, advises to stock up on garlic
Bram Stoker books: How ’Dracula’ created the modern vampire
The Great New England Vampire Panic
15th annual European "Bat Night": For the Love of Bats
Latest News from our Front Page
An Eye For Odin
The Anglo-Saxon Sutton Hoo helmet is a religious artefact dedicated to Woden the one eyed god of war. Recent research indicates that numerous other archeaological artefacts also provide evidence that one eye on various figures has been deliberately removed as part of a Woden ritual.
Read the original essay by Neil Price and Paul Mortimer here:
Music: Faunus Amadeus Loki - Strange ...
Ed Miliband: "As a friend of Israel and a Jew, I'm a proud member of this community" & "The Jewish Manifesto"
Editor's comment: With just a few days to go to the British election, here are a few tidbits that the English voter might want to know about concerning the leader of the Labour party, Ed Miliband.
Labour Leader Ed Miliband on the Board of Deputies' Jewish Manifesto
By Ed Miliband, Leader of the Opposition in the UK. (Or should that be the ...
"Sweden is ruled by unelected policy plotters"
Editor's Comment: As usual, the power in Sweden is behind the scenes, unelected and weaved into the bureaucracy so that Swedes have no control or influence over what happens in the country.
Sweden has long been seen as the epitome of a healthy democracy. But in this week's debate article, three researchers argue that an increase in unelected behind-the-scenes operators is ...
Israel to airlift 25 babies born to surrogates out of Nepal
Ya'ari is one of 26 babies airlifted by the Israeli government and brought to Israel to be with their parents after the Nepal earthquake. (Derek Stoffel/CBC)Israel said Sunday it plans to airlift 25 infants from quake-hit Nepal born to surrogate mothers, along with their Israeli parents, most of them homosexual couples.
Officials said Israel was sending a military delegation to offer ...
Ed Miliband is a f****** communist, says Noel Gallagher
Noel Gallagher has warned Ed Miliband is a 'f******* communist' who will 'fail us all' if Labour wins the election next week.
The former Oasis guitarist admitted that he did not plan to vote on Thursday because he could not 'get behind' any of the parties.
His foul-mouthed outburst at Mr Miliband is a long way from New Labour's Cool Brittania heyday, ...
|More News » |