Flap-necked chameleons change colour to match their background

Area of Science:

• Animal behavior
• Evolutionary biology
• Visual ecology

Background:

• Popular belief suggests chameleons change color to match surroundings.
• Scientific evidence indicates color change is mainly for social signaling and thermoregulation.
• Chameleons typically use a general camouflage color rather than specific background matching.

Purpose of the Study:

• To investigate the background-matching abilities of flap-necked chameleons (Chamaeleo dilepis) under controlled conditions.
• To determine if chameleons actively adjust their coloration to specific backgrounds for camouflage.

Main Methods:

• Chameleons were placed on standardized colored and patterned backgrounds.
• Appearance was measured over time using models of predator vision.
• Color and brightness changes were analyzed in relation to background stimuli.

Main Results:

• Chameleons adjusted brightness to match black backgrounds.
• Color change occurred to match certain hues, notably yellow.
• No matching of background patterns was observed.
• Evidence supports camouflage as a function of chameleon color change.

Conclusions:

• Flap-necked chameleons demonstrate an ability to modify their appearance for camouflage.
• Color and brightness adjustments facilitate blending with specific background colors.
• This research supports the role of active camouflage in chameleon coloration.