Marc
24th March 2005, 09:23 PM
Here's another animal thing I thought to be interesting:
http://elsmar.com/jpg/running_vampire_bat.jpg Vampires Run: Bats on treadmills show high-speed gait (http://www.sciencenews.org/articles/20050319/fob2.asp)
Susan Milius
Vampire bats have evolved their own form of running, the first test of these creatures on a treadmill shows. As the treadmill pace picks up, they switch to a run, with all limbs airborne at one point in each stride.
These are the only bats known to run, so their ancestors probably didn't go jogging, reports Daniel Riskin of Cornell University.
"Because vampire bats evolved the ability to run independently of other runners, they're a separate group for people to test their hypotheses on," Riskin says. The news comes as a surprise, comments John Hutchinson of the Royal Veterinary College in London. "It's one of the few—or only—examples I can think of in which a lineage has re-evolved running."
Riskin started out studying how bats of various species move across a surface, which they generally do badly. The least effective of them "just smack their wings against the ground and freak out," never successfully taking a step, he says.
Other species can shuffle. "The typical bat can get from A to B, but it looks really clumsy while it does it," Riskin says.
In contrast, he ranks the ground-traversing skills of vampire bats as "off-the-scale good." The 8-centimeter-long animals move nimbly in any direction, easily making the transition from ground to air movement. They can jump into flight from a standing start in some 30 milliseconds.
That's a useful skill for an animal that can spend 40 or so minutes at a time licking a small cut that it makes on a bigger animal. All three species of vampire bats require blood meals to survive. The common vampire bat (Desmodus rotundus), which Riskin studies, prefers cattle as a blood source. Riskin tested wild bats in Trinidad by setting up fine netting at night around a cluster of cattle and capturing bats that flew in for dinner. The Movie: LEAPS AND BOUNDS. A vampire bat on a treadmill loping along at 0.6 meter per second. Video-camera images taken every 24 milliseconds captured the unusual mode of locomotion.
http://elsmar.com/jpg/running_vampire_bat.jpg Vampires Run: Bats on treadmills show high-speed gait (http://www.sciencenews.org/articles/20050319/fob2.asp)
Susan Milius
Vampire bats have evolved their own form of running, the first test of these creatures on a treadmill shows. As the treadmill pace picks up, they switch to a run, with all limbs airborne at one point in each stride.
These are the only bats known to run, so their ancestors probably didn't go jogging, reports Daniel Riskin of Cornell University.
"Because vampire bats evolved the ability to run independently of other runners, they're a separate group for people to test their hypotheses on," Riskin says. The news comes as a surprise, comments John Hutchinson of the Royal Veterinary College in London. "It's one of the few—or only—examples I can think of in which a lineage has re-evolved running."
Riskin started out studying how bats of various species move across a surface, which they generally do badly. The least effective of them "just smack their wings against the ground and freak out," never successfully taking a step, he says.
Other species can shuffle. "The typical bat can get from A to B, but it looks really clumsy while it does it," Riskin says.
In contrast, he ranks the ground-traversing skills of vampire bats as "off-the-scale good." The 8-centimeter-long animals move nimbly in any direction, easily making the transition from ground to air movement. They can jump into flight from a standing start in some 30 milliseconds.
That's a useful skill for an animal that can spend 40 or so minutes at a time licking a small cut that it makes on a bigger animal. All three species of vampire bats require blood meals to survive. The common vampire bat (Desmodus rotundus), which Riskin studies, prefers cattle as a blood source. Riskin tested wild bats in Trinidad by setting up fine netting at night around a cluster of cattle and capturing bats that flew in for dinner. The Movie: LEAPS AND BOUNDS. A vampire bat on a treadmill loping along at 0.6 meter per second. Video-camera images taken every 24 milliseconds captured the unusual mode of locomotion.
