Possible levels of animal consciousness with reference to grey parrots (Psittacus erithacus

SYNOPSIS. Researchers often study nonhuman abilities by assuming their subjects form representations about perceived stimuli and then process such information; why then would consciousness be required, and, if required, at what level? Argu-ments about nonhuman consciousness range from claims of levels comparable to humans to refutation of any need to study such phenomena. We suggest that (a) species exhibit different levels attuned to their ecological niches, and (b) animals, within their maximum possible level, exhibit different extents of awareness appro-priate to particular situations, much like humans (presumably conscious) who often act without conscious awareness of factors controlling their behavior. We propose that, to engage in complex information processing, animals likely exhibit perceptual consciousness sensu Natsoulas (1978), i.e., are aware of what is being processed. We discuss these issues and provide examples suggesting perceptual consciousness