Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Vampire Bats Keep Out of Trouble by Running

17.03.2005


Although most people think of bats as stealthy mammals that flit about in the night sky, at least one species has evolved a terrestrial trot never before seen in bats, according to a recent Cornell University study.



It’s known that the common vampire bats of Central and South America behave much more like four-legged terrestrial mammals, in that they like to walk around on the ground; other bat species fumble helplessly when left to walk. But researchers in Cornell’s College of Veterinary Medicine have discovered that these bats not only walk but run. The unprecedented gait of Desmodus rotundus is described in a brief communication in this week’s issue of Nature magazine (March 17, 2005) from Daniel Riskin, Cornell graduate student in zoology, and his adviser John W. Hermanson, associate professor of biomedical sciences.

What seemed like a crazy idea -- challenging these bats on an increasingly speedy treadmill -- revealed a novel ability which the researchers believe evolved independently to facilitate feeding behavior. "What we observed was like a horse going from a walk to a gallop over a very short amount of time," Riskin explains. The researchers kept increasing the speed of the treadmill and, much to their surprise, their subjects broke into a run.


"They just seem to do everything a little differently from the general bat rule," Riskin says about what he refers to as the "cute, adorable, big-eyed and family-oriented" vampire bats.

Not only are vampire bats unusual because they run, but also in the way that they power their gait. "Unlike most animals which use their hind legs as a source of power, these exceptional creatures power their run with their forelimbs," Hermanson explains. Getting most of the push from their long forelimbs -- actually their wings and therefore very strong -- the bats run more like a small gorilla than a comparable four-legged creature like a mouse. They run up to about 2.5 miles per hour. Although many of the 1,100 species of bats are known to walk, the common vampire is the only one so far to pass Riskin and Hermanson’s treadmill test and break into a running gait. With the introduction of large herds of livestock into their native environments of Central and South America, these bats don’t need to hurry to catch the cattle from which they extract perhaps a tablespoon of blood at a time for sustenance. They feed while their prey are sleeping, spending perhaps 10 minutes drinking from the small cuts they make. However, running may help them avoid being stepped on, Riskin suggests. More likely, the researchers say, the ability to run evolved long ago, when vampire bats had to prey on faster South American athletes such as the agouti, a rodent about the size of a hare, which might wake up and take a swipe at the nocturnal visitor. It remains unclear exactly what the native prey were before the introduction of cattle, he adds.

The Cornell zoologists plan to go a step further and compare the vampire bat to another species of bat endemic to New Zealand. Riskin explains, "The vampire bat is good on the ground because when you feed on the hoof of an animal that weighs 14,000 times more than you do, it’s dangerous." Also, there are and always have been a variety of predators in the Western Hemisphere environment. In contrast, Riskin says, the bats and birds of New Zealand had no predators to keep them flying. Many of the birds became flightless walkers, and the bats walk more than others, as flight is energetically very expensive.

"Vampire bats in Latin America are good on the ground because it’s a very dangerous place, and bats in New Zealand are good on the ground because it’s a very safe place," Riskin says. While New Zealand bats definitely don’t run -- they failed the treadmill test -- Riskin wants to compare the walking gaits of the two species.

Cornell undergraduate Gerald Carter contributed to the study.

This release was prepared by Cornell News Service science-writing intern Sarah Davidson.

| newswise
Further information:
http://www.cornell.edu

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>