Microhabitat choice in island lizards enhances camouflage against avian predators

Abstract

Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation.

Gliding lizards use the position of the sun to enhance social display

“…Many recent studies have shown animals are able to integrate information about their own appearance and their surroundings to modulate behaviour and reduce predation risk [27][28][29][30][31]. Studies addressing the interaction between colour and behaviour in signalling are rarer, but they too show that animals have the capacity to select display locations and orientations that improve signal effectiveness [5,10,12].…”

The Role of Life-History and Ecology in the Evolution of Color Patterns in Australian Chrysomeline Beetles

“…Together with our findings that red pattern does not differ with beetle length, this suggests that the less common adoption of a typical conspicuous color, red, by polyphagous species, could be to limit conspicuousness when they feed on diverse backgrounds. Recent studies of lizards (Marshall et al, 2016) and crabs (Uy et al, 2017) indicate that animals actively choose to match their background. As the spectral sensitivities of chrysomelids appear to be limited to UV, blue and green but not red (Sharkey et al, 2017), active background matching may not fully explain color pattern differences of beetles with their host plant.…”

Camouflage

“…Colour change (Umbers et al ., ; Duarte, Flores & Stevens, ), substrate selection in relation to phenotype (e.g. Kang et al ., ; Kjernsmo & Merilaita, ; Lovell et al ., ; Marshall, Philpot & Stevens, ; Smithers et al ., ), and orientation behaviour to match the orientation of substrate textures (Kang et al ., , ,b), are also powerful evidence for the importance of background matching for concealment (see review by Stevens & Ruxton, ).…”