Pigeon Art Critics

Ars Technica provided this link to a Japanese bit of research in which pigeons were conditionally trained to evaluate child drawings and determine whether their art is bad or good. Results suggest that pigeons were less successful with grayscale images but could discriminate well with colours and patterns. Although the author suggests that pigeons may even be able to appreciate beauty in the same way as humans, how much of this is simply about a pigeon learning to get a tasty snack when he picks a conditioned right answer?