Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researcher Finds Tailless Lizards Lose Agility

16.02.2009
When in a predator’s grips, many lizards drop their tails to escape. But what price do they pay for freedom? A team led by biology professor Gary Gillis of Mount Holyoke College found the lizards were compromised: They could no longer jump without tumbling backwards, making it difficult to land safely when jumping between branches.

Among nature's more interesting wonders is the ability of many lizard species to escape their predators. When caught in a vulnerable position, they simply drop their tails, leaving the twitching body part to distract the predator as they scamper to safety.

But, says Gary Gillis, a biology professor at Mount Holyoke College, the lizards lose significant mobility and agility in return for this life-saving natural escape mechanism.

Up to 50 percent of some lizard populations seem to have traded part of their tails in exchange for escape, according to Gillis. While the tails typically grow back in three to six months, Gillis wondered how the loss might impact a branch-hopping, tree-dwelling lizard’s mobility and ability to survive in the interim. Teaming up with undergraduate student Lauren Bonvini, he began recording lizard leaps to observe how well the reptiles coped without their tails. The results are being published February 13 in The Journal of Experimental Biology (http://jeb.biologists.org/).

Constructing a jumping arena from boxes and fine sandpaper, Gillis and Bonvini gently encouraged arboreal Anolis carolinensis (anole) lizards to launch themselves from an 11-centimeter-high platform while filming the animals’ jumps. The lizards performed well, launching themselves by pushing off with their back feet and landing gracefully, covering distances ranging from 14.9 to 29.9 centimeters.

But how well would the animals perform without their tails? After holding the lizards' tails to encourage them to drop them, just as they would with a predator, Bonvini then persuaded the tailless reptiles to jump while Gillis filmed them. As soon as the first animal took to the air, Gillis knew something was different.

"It looked weird," he said. "The animals became blurred as they jumped."

Replaying the animal's jump in slow motion, the team could see that it was tumbling backwards, out of control, as its tail stump flailed. Filming other tailless anoles, four backflipped out of control, although two others seemed to manage their trajectories better.

Teaming up with Duncan Irschick of the University of Massachusetts, Amherst, to analyze the reptiles’ leaps, Gillis could see that everything about the tailless lizards’ take-off was exactly the same as it had been before they lost the appendage – until they left the jump stage. The lizards then began flipping backwards by more than 30 degrees; some tumbled so far that they landed on their backs. The team also realized that when the lizards with whole tails took off, they raised the base of their tails as the rest of the appendage trailed along the ground, as if it was somehow stabilizing the take-off.

"If jumping and landing are important for lizards, they are clearly compromised after losing their tails. Coordinated landing on a branch is out of the question when spinning backwards," said Gillis. Escaping lizards pay a significant ecological cost for their life-saving quick-release system, he concluded.

So how do the lizards use their tails to ensure a safe touchdown? Gillis isn’t sure whether they push down with their tails at take-off to prevent themselves from spinning, or whether the trailing tail passively stabilizes the animal’s departure. He is continuing his research to determine how lizards adjust to life without their tails, with differential degrees of tail loss, and after the tails have grown back.

Related Links:
http://www.mtholyoke.edu/acad/misc/profile/ggillis.shtml
http://jeb.biologists.org
Research video is available.
IF REPORTING ON THIS STORY, PLEASE MENTION THE JOURNAL OF EXPERIMENTAL BIOLOGY AS THE SOURCE AND, IF REPORTING ONLINE, PLEASE CARRY A LINK TO: http://jeb.biologists.org

Full text of the article is available ON REQUEST. To obtain a copy contact Kathryn Knight, The Journal Of Experimental Biology, Cambridge, UK. Tel: +44 (0)1223 425525, or email kathryn@biologists.com

Gary Gillis | Newswise Science News
Further information:
http://www.mtholyoke.edu
http://jeb.biologists.org
http://www.mtholyoke.edu/acad/misc/profile/ggillis.shtml

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>