Many Greco-Roman anecdotes about interactions between images and their viewers raise the issue of naturalism and its deceptive powers. Perhaps most famously in Pliny's anecdote about grapes painted by Parrhasius, the birds mistake the image for what it represents and start pecking at the painting (Natural History xxxv.65). Here we have a typical case of ontological oscillation: in the perception of the viewer the image dissolves into, or is elided with what it represents. Much commentary has focused on the painter’s virtuosity in creating a lifelike illusion, yet one aspect remains underexplored: the behaviour of the birds themselves. The story is not simply about artistic triumph; it also presupposes that animals possess the perceptual and semiotic abilities needed to be deceived by an image.  

Now animals are not only deceived by images: in camouflage they are also deceivers. Both Parrhasius' painting and the octopus who becomes the image of its surroundings present themselves as something they are not. The painting deceives the birds, just as the octopus deceives its predators into taking it for something it is not. In Antiquity this ability of animals to create deceptive images was often noted, both in zoological writing, but also represented in vase painting and mosaics. Even though Pliny's anecdote is not about camouflage as such, it is a major statement about similarities between animal and human image-making and -viewing. 

Taking into consideration visual deception by animals shows that naturalism does not always result in an awareness of the pictorial illusion (as in trompe l'oeil paintings). Instead, visual deception modelled on animal deceptive behaviour, and sometimes using animal shapes to deceive, leads to an unstable relation in which the viewer remains captivated in visual ambiguity. At the same time, such forms of deception should not be understood merely as representational phenomena. As is already evident in animal camouflage, they function as forms of adaptive and social behaviour, embedded in interactions between agents and observers, and aimed at survival. In this sense, naturalism operates not only at the level of images, but within behavioural strategies. 

In other words, my aim is to consider human and animal image-making as part of a spectrum of mimetic behaviour, perceptual and cognitive abilities shared by human and animals. Where Philippe Descola has recently given an anthropological framework to naturalist painting of the early modern period, I here propose to give an ethological foundation to naturalism in the arts.