Local adaptation and divergence in colour signal conspicuousness between monomorphic and polymorphic lineages in a...

Area of Science:

• Ecology and Evolutionary Biology
• Animal Coloration and Vision
• Behavioral Ecology

Background:

• Animal coloration evolves due to visual environments and receiver pressures (conspecifics, predators).
• Geographic variation in background habitats can lead to divergent selection on animal traits, including coloration.

Purpose of the Study:

• To test for local adaptation in coloration between two divergent lineages of the rock-dwelling lizard, Ctenophorus decresii.
• To assess how lineage-specific color patches (throat, dorsal, lateral) provide conspicuousness to conspecifics and/or crypsis to avian predators in native versus non-native environments.

Main Methods:

• Comparative analysis of visual contrast for color patches between lizard lineages and their native/non-native backgrounds.
• Utilized animal color vision models to simulate perception by conspecifics and avian predators.
• Examined throat, dorsal, and lateral coloration in relation to rock and lichen backgrounds.

Main Results:

• Throat coloration showed stronger contrast with native lichen, not general rock backgrounds.
• Lateral (neck) coloration exhibited closer matching to native lichen backgrounds.
• Southern males' dorsal coloration was more conspicuous to birds, but both lineages showed similar conspicuousness against their respective native backgrounds.

Conclusions:

• Results support local adaptation of multiple color traits in Ctenophorus decresii, influenced by geographic variation in background environments.
• Divergent selection pressures from different receivers (conspecifics, predators) and varied backgrounds have shaped lineage-specific lizard coloration.