Camouflage can be attained via mechanisms such as background matching (resembling the general background) and disruptive coloration (hindering the detection of an animal’s outline). However, despite much conceptual work with artificial stimuli there have to date been few studies of how such camouflage types work in real animals in their natural environments. Here, using avian vision models and image analysis, we tested which concealing mechanisms operate to provide camouflage during behavioral choice of a resting position in two bark-resting moths, Hypomecis roboraria and Jankowskia fuscaria. We found that both species reinforced their crypticity in terms of both background matching and disruptive coloration. However the detailed mechanisms (such as achromatic/chromatic matching or pattern direction matching) that each species exploits differed between the two species. Additionally, we found substantial correlation between the degree of background matching and disruptive coloration, which supports previous work suggesting that these two different concealing mechanisms work together to confer camouflage. Our results clearly demonstrate that an appropriate behavioral choice of background is essential to improve camouflaged against natural predators, and highlight the interrelation between different concealing mechanisms in real prey.

• Changku Kang(Laboratory of Behavioral Ecology and Evolution, School of Biological Sciences, Seoul National University, Laboratory of Animal Communication, Division of EcoScience, Ewha Womans University)
• Martin Stevens(Centre for Ecology and Conservation, University of Exeter, Penryn Campus)
• Jongyeol Moon(Laboratory of Behavioral Ecology and Evolution, School of Biological Sciences, Seoul National University)
• Sangim Lee(Laboratory of Behavioral Ecology and Evolution, School of Biological Sciences, Seoul National University)
• Piotr G. Jablonski(Laboratory of Behavioral Ecology and Evolution, School of Biological Sciences, Seoul National University)