Resolution of multi-receiver trade-offs in wall lizard colouration

The evolutionary significance of animal colouration stems from the contrasting selective pressures it faces. Vibrant, non-threatening colour patterns can simultaneously bolster conspecific communication while making individuals more visible to predators. To resolve this trade-off, colour-patterns can be fine-tuned to align with the perceptual capacities of various receivers.

Researchers investigated whether the dorsal colour-patterns of the Lusitanian wall lizard (Podarcis lusitanicus) are tailored to suit the perceptual abilities of relevant receivers at different viewing distances, while also considering the visual acuity of conspecifics and predators. It was found that conspecifics and snakes detected chromatic information at shorter ranges, whereas achromatic and luminance information were discernible at greater distances.

Birds displayed a consistent reduction in detectability across the colour-pattern components as viewing distance increased. Larger male lizards maintained high chromatic detectability across all receivers, despite the general trend of decreasing detectability with distance. On the other hand, females and smaller individuals exhibited less conspicuous colour patterns, aligning with a predator avoidance strategy.

The findings demonstrate that lizards effectively navigate the trade-off between conspecific communication and predator detection by adjusting colour-pattern discernibility based on the distance of the receiver. However, this resolution fails for large males, where the advantages of conspicuous chromatic patterns for intraspecific communication may outweigh the heightened risk of predation.