Male anole lizards signal ownership of their territory by sitting up on a tree trunk, bobbing their heads up and down and extending a colorful throat pouch. They can spot a rival lizard up to 25 meters away, said Terry Ord, a postdoctoral researcher at UC Davis who is working with Judy Stamps, professor of evolution and ecology.
The lizards' signals need to be strong enough for a rival to see, but not vivid enough to say "eat me" to a passing predator. But their forest home can be a visually noisy environment, with branches and leaves waving in the breeze and casting patterns of light and shade.
"They have to have a strategy to get their message across," Ord said.
Ord videotaped two species of anole lizards, Anolis cristatellus and Anolis gundlachi, in the Caribbean National Forest in Puerto Rico. He found that the more "visual noise" in the background, the faster and more exaggerated the movements of the lizards.
Anole lizards are interesting to evolutionary biologists because different species are found on different islands all over the Caribbean. The lizards are not particularly closely related -- they are separated by 30 million years of evolution -- but they live in similar environments with the same obstacles to communication. So Ord is using them as a model to investigate the evolution of such signals.
The other authors on the paper, which is published online in Proceedings of the Royal Society part B, are Richard A. Peters, Australian National University, Canberra; and Barbara Clucas, a graduate student in animal behavior at UC Davis.
Source: UC Davis
Related stories:
Dinosaurrific! New Dinosaur Supertree
(PhysOrg.com) -- It has long been debated whether dinosaurs were part of the ‘Terrestrial Revolution’ that occurred some 100 million years ago during the Cretaceous when birds, mammals, flowering plants, insects and reptiles all underwent a rapid expansion.
Big vegetarian mammals can play a critical role in maintaining healthy ecosystems, study finds
Removing large herbivorous mammals from the African savanna can cause a dramatic shift in the relative abundance of species throughout the food chain, according to scientists from Stanford University, Princeton University and the University of California-Davis. Their findings were published in the Jan. 2 edition of
Proceedings of the National Academy of Sciences (PNAS).
Rapid shift in natural selection reported
U.S. evolutionary scientists say they have found evolution as a process can occur during eons or within months as a population's needs change.
Researchers Find Oldest Gecko Fossil Ever Discovered
(PhysOrg.com) -- Scientists from Oregon State University and the Natural History Museum in London have announced the discovery of the oldest known fossil of a gecko, with body parts that are forever preserved in life-like form after 100 million years of being entombed in amber.
Jamaican lizards' shows of strength mark territory at dawn, dusk
What does Jack LaLanne have in common with a Jamaican lizard? Like the ageless fitness guru, the lizards greet each new day with vigorous push-ups. That's according to a new study showing that male Anolis lizards engage in impressive displays of reptilian strength -- push-ups, head bobs, and threatening extension of a colorful neck flap called a dewlap -- to defend their territory at dawn and dusk.
Forest birds evolved early, DNA shows
(PhysOrg.com) -- Evolution seems to have happened in fits and starts -- at least that's what the fossil record shows. From trilobites to pterodactyls, ammonites to Archaeopteryx, scientists find the same pattern: brief bursts of innovation in which a single species or branch on the tree of life turns into a cluster of new twigs, then lapses into long stretches ruled by the status quo.
Molecular analysis confirms T. rex's evolutionary link to birds
Putting more meat on the theory that dinosaurs’ closest living relatives are modern-day birds, molecular analysis of a shred of 68-million-year-old Tyrannosaurus rex protein – along with that of 21 modern species – confirms that dinosaurs share common ancestry with chickens, ostriches, and to a lesser extent, alligators.
Lizards Undergo Rapid Evolution after Introduction to a New Home
In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the South Adriatic Sea, to the neighboring island of Pod Mrcaru. Now, an international team of researchers has shown that introducing these small, green-backed lizards, Podarcis sicula, to a new environment caused them to undergo rapid and large-scale evolutionary changes.
