Exploring the Müller-Lyer illusion in a nonavian reptile (Pogona vitticeps).

Visual illusions have been widely used to compare visual perception among birds and mammals to assess whether animals interpret and alter visual inputs like humans, or if they detect them with little or no variability. Here, we investigated whether a nonavian reptile (Pogona vitticeps) perceives the Müller-Lyer illusion, an illusion that causes a misperception of the relative length of 2 line segments. We observed the animals' spontaneous...