Intraspecific Variation in Dorsal Colour Patterns of Amphibolurus muricatus Lizards From the Perspective of Relevant...

The visual environment animals occupy is often comprised of spatially distinct microhabitats featuring different and varying backgrounds, lighting conditions, temperatures, feeding opportunities and threats. For species employing colouration in some capacity, efficacy can vary substantially between these; thus, we expect some variation within species to adapt to the traits of specific microhabitats. Cryptic animals can be particularly sensitive to changes or choices in habitat and predation threats and often display intraspecific variation of their colour patterns. One such species, the Jacky dragon (Amphibolurus muricatus), occurs across a wide geographic range incorporating several distinct habitat types and possesses dorsal camouflage patterns that aid in avoiding detection from a range of potential predators. Here we investigate intraspecific variation of the dorsal patterns of A. muricatus within the context of relevant observers at multiple viewing distances. Using multispectral photography, contemporary analysis software and specifically constructed visual models for the Jacky dragon and two avian predators, we quantified patterns of individuals collected across the geographic range of the species. Larger lizards appear to have more distinct dorsal patches to lizards at close range, but avian predators see reduced pattern diversity and complexity. At a distance, both predators see fewer clusters, and size has less effect. Close-up, males show more distinct patches, contrast and luminance to lizards, but lower contrast to kookaburras. Furthermore, differences are also apparent between genetic clades and habitat characteristics, with lizards in coastal heath exhibiting greater pattern diversity and complexity to all observers. Importantly, these differences are mediated by observer identity, as significant effects are not consistent across different visual systems. Our results suggest that variation in the visual appearance of these lizards is multifaceted and in response to both general and local selection pressures.