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Visually guided avoidance in the chameleon (Chamaeleo chameleon): response patterns and lateralization.

Lustig A, Ketter-Katz H, Katzir G - PLoS ONE (2012)

Bottom Line: We found two equal-sized sub-groups, each displaying lateralization of motor responses to a given direction of stimulus approach.Such an anti-symmetrical distribution of lateralization in a population may be indicative of situations in which organisms are regularly exposed to crucial stimuli from all spatial directions.This is because a bimodal distribution of responses to threat in a natural population will reduce the spatial advantage of predators.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology and Ethology, University of Haifa, Haifa, Israel. Lustigavi@gmail.com

ABSTRACT
The common chameleon, Chamaeleo chameleon, is an arboreal lizard with highly independent, large-amplitude eye movements. In response to a moving threat, a chameleon on a perch responds with distinct avoidance movements that are expressed in its continuous positioning on the side of the perch distal to the threat. We analyzed body-exposure patterns during threat avoidance for evidence of lateralization, that is, asymmetry at the functional/behavioral levels. Chameleons were exposed to a threat approaching horizontally from the left or right, as they held onto a vertical pole that was either wider or narrower than the width of their head, providing, respectively, monocular or binocular viewing of the threat. We found two equal-sized sub-groups, each displaying lateralization of motor responses to a given direction of stimulus approach. Such an anti-symmetrical distribution of lateralization in a population may be indicative of situations in which organisms are regularly exposed to crucial stimuli from all spatial directions. This is because a bimodal distribution of responses to threat in a natural population will reduce the spatial advantage of predators.

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Related in: MedlinePlus

Ventral surface exposure of the two side-biased groups on a wide pole, as a function of threat-approach direction.Exposure (mean ± SE) under right- or left-approaching threats, for chameleons of the right-biased (N  = 10) and left-biased (N  = 7) groups, in tests on a wide pole at the onset of pole rotation (Initial), end of pole rotation (Rotation end), and end of test (Final).
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pone-0037875-g014: Ventral surface exposure of the two side-biased groups on a wide pole, as a function of threat-approach direction.Exposure (mean ± SE) under right- or left-approaching threats, for chameleons of the right-biased (N  = 10) and left-biased (N  = 7) groups, in tests on a wide pole at the onset of pole rotation (Initial), end of pole rotation (Rotation end), and end of test (Final).


Visually guided avoidance in the chameleon (Chamaeleo chameleon): response patterns and lateralization.

Lustig A, Ketter-Katz H, Katzir G - PLoS ONE (2012)

Ventral surface exposure of the two side-biased groups on a wide pole, as a function of threat-approach direction.Exposure (mean ± SE) under right- or left-approaching threats, for chameleons of the right-biased (N  = 10) and left-biased (N  = 7) groups, in tests on a wide pole at the onset of pole rotation (Initial), end of pole rotation (Rotation end), and end of test (Final).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369868&req=5

pone-0037875-g014: Ventral surface exposure of the two side-biased groups on a wide pole, as a function of threat-approach direction.Exposure (mean ± SE) under right- or left-approaching threats, for chameleons of the right-biased (N  = 10) and left-biased (N  = 7) groups, in tests on a wide pole at the onset of pole rotation (Initial), end of pole rotation (Rotation end), and end of test (Final).
Bottom Line: We found two equal-sized sub-groups, each displaying lateralization of motor responses to a given direction of stimulus approach.Such an anti-symmetrical distribution of lateralization in a population may be indicative of situations in which organisms are regularly exposed to crucial stimuli from all spatial directions.This is because a bimodal distribution of responses to threat in a natural population will reduce the spatial advantage of predators.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology and Ethology, University of Haifa, Haifa, Israel. Lustigavi@gmail.com

ABSTRACT
The common chameleon, Chamaeleo chameleon, is an arboreal lizard with highly independent, large-amplitude eye movements. In response to a moving threat, a chameleon on a perch responds with distinct avoidance movements that are expressed in its continuous positioning on the side of the perch distal to the threat. We analyzed body-exposure patterns during threat avoidance for evidence of lateralization, that is, asymmetry at the functional/behavioral levels. Chameleons were exposed to a threat approaching horizontally from the left or right, as they held onto a vertical pole that was either wider or narrower than the width of their head, providing, respectively, monocular or binocular viewing of the threat. We found two equal-sized sub-groups, each displaying lateralization of motor responses to a given direction of stimulus approach. Such an anti-symmetrical distribution of lateralization in a population may be indicative of situations in which organisms are regularly exposed to crucial stimuli from all spatial directions. This is because a bimodal distribution of responses to threat in a natural population will reduce the spatial advantage of predators.

Show MeSH
Related in: MedlinePlus