More lizards responded with the same communication signal to robots having the same physical characteristics
(PRWEB) July 15, 2015
Herpetologica – Among animals, color patterns on an individual’s body, and visual or acoustic signals, are often used to communicate with other members of the species. Males of many species of lizards bob their head up and down, or extend and retract a patch of skin on their throats (an action known as dewlapping), to indicate mate quality and intent to defend territory.
Two articles, “Comparison of Headbob Displays in Gray-Dewlapped and Red-Dewlapped Populations of Green Anoles (Anolis carolinensis)” and “Responses of Anolis grahami Males to Manipulations of Species' Identity and Components of Displays in Lizard Robots,” in the new issue of Herpetologica, take a closer look at these visual cues and how they are perceived among lizard species. In the first article, the authors compare the communication signals of gray and red-dewlapped lizards and hypothesize that their color difference has an effect on their communications. In the second article, the authors use man-made robot lizards to examine the subtleties of visual communication among lizards.
Because the gray-dewlapped lizards differ from red-dewlapped individuals in their morphology, life-history, and genetics, differences among their head-bobbing communication signals were hypothesized. When the authors measured the head bobbing signals of the gray and red-dewlapped lizards, both intrasexually and intersexually, they did not find any differences. This led the authors to consider mating patterns and morphological persistence, because female lizards did not seem to differentiate between signals from gray or red-throated males.
In the second article, the authors constructed robot lizards to gauge the importance of specific communication signals—dewlapping, head-bobbing, or physical characteristics. In one experiment, the authors used a combination of physicality and dewlapping or head-bobbing. As predicted, more lizards responded with the same communication signal to robots having the same physical characteristics. In a second experiment, physicality and only one communication signal were emphasized. The lizards responded more to the communication signal than to the physical characteristics of the robot, contradicting the original hypothesis of the authors.
Full text of the article, “Comparison of Headbob Displays in Gray-Dewlapped and Red-Dewlapped Populations of Green Anoles (Anolis carolinensis)” and “Responses of Anolis grahami Males to Manipulations of Species Identity and Components of Displays in Lizard Robots,” Herpetologica, Vol. 71, No. 2, 2015, are now available online.
Herpetologica is a quarterly journal of The Herpetologists' League, containing original research articles on the biology of amphibians and reptiles. The journal serves herpetologists, biologists, ecologists, conservationists, researchers, and others interested in furthering knowledge of the biology of amphibians and reptiles. To learn more about the society, please visit: http://www.herpetologistsleague.org.