Categorical learning between 'male' and 'female' photographic human faces in jungle crows (Corvus macrorhynchos)

▶ Jungle crows categorize human face images according to sex. ▶ Colour cues are the most salient features used for categorical decision. ▶ Facial contour also controlled discriminative behaviour of some individuals. ▶ Jungle crows categorize human face images on the basis of perceptual similarity.