Glossiness disrupts predator localisation of moving prey.

Movement is the "enemy of camouflage", but most animals must move to find resources, such as mates, food and shelter. Therefore, strategies that disrupt predator localization or speed perception of moving prey can play a crucial role in prey survival. Shiny or glossy appearances, which are characterised by having a high degree of specular (mirror-like) reflection of incident light, can disrupt predator hunting behaviours towards moving prey. Different mechanisms may explain this effect, but no study has attempted to identify the mechanisms that disrupt perception of moving glossy prey by non-human predators. Here, we present moving glossy green or grey targets to jumping spiders (Maratus griseus) and precisely document predator hunting behaviours using high speed videography. Jumping spiders were less precise at tracking glossy targets compared to control targets, suggesting glossiness may disrupt localisation of moving targets. Importantly for prey, jumping spider attack jumps were substantially less accurate towards glossy prey compared to control targets. These results were independent of underlying target colour, suggesting benefits of glossiness may be generalisable to differently coloured glossy animals. Our results indicate that glossiness, when paired with motion, creates an unpredictable target that is difficult for predators to localise, offering insights into the prevalence of dynamically coloured organisms in nature.