Camouflage through behavior in moths: the role of background matching and disruptive coloration

摘要

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 2 bark-resting moths, Hypomecis roboraria and Jankowskia fuscaria. Our results suggest 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 2 species. Our results demonstrate that an appropriate behavioral choice of background and body orientation is important to improve camouflage against natural predators, and highlight the mechanisms that confer camouflage to cryptic animals in their natural habitats.