for National Geographic News
Lizards use "push ups" to attract attention in noisy environments, according to new research that used robotic lizards.
The robots, fashioned to mimic the appearance and body language of live anole lizards, helped scientists confirm a longheld theory that animals use grand gestures, such as the lizard push-up, and loud noises to get the attention of other members of their species in chaotic, noisy environments.
These so-called alert signals are used to cut through environmental noise, according to new research on anoles in Puerto Rico.
These reptiles create exaggerated, eye-catching push-ups to grab their neighbors' attention before using more nuanced head-bobbing gestures to communicate territorial and fitness claims, according to the study.
But the lizards are more likely to do push-ups when visual obstructions or visual "noise," such as low light or blowing branches, would otherwise drown out the head-bobbing.
"They are actually changing their behavior to compensate for those [noises]," said Terry Ord, a research associate in evolution and ecology at the University of California in Davis.
The lizard research clearly demonstrates that animals use visual alert signals, said Ord, who led the study published online Tuesday in the journal Proceedings of the National Academy of Sciences.
Alert signaling is thought to be widespread in the animal world, but had previously only been definitively shown in towhees, a type of bird that sends audible alerts, according to Ord.
Other studies have suggested tree frogs and coyotes also use audible alerts.
(The research was funded in part by a grant from the National Geographic Society's Committee for Research and Exploration. The National Geographic Society owns National Geographic News.)
Puerto Rican anole lizards live on tree trunks, often positioning themselves with their heads pointed toward the ground.
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