title: Ravens attribute visual access to unseen competitors.
abstract: Recent studies purported to demonstrate that chimpanzees, monkeys and corvids possess a basic Theory of Mind, the ability to attribute mental states like seeing to others. However, these studies remain controversial because they share a common confound: the conspecific's line of gaze, which could serve as an associative cue. Here, we show that ravens Corvus corax take into account the visual access of others, even when they cannot see a conspecific. Specifically, we find that ravens guard their caches against discovery in response to the sounds of conspecifics when a peephole is open but not when it is closed. Our results suggest that ravens can generalize from their own perceptual experience to infer the possibility of being seen. These findings confirm and unite previous work, providing strong evidence that ravens are more than mere behaviour-readers.
authors.affiliation: Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria.|Haidlhof Research Station, University of Vienna and University of Veterinary Medicine, 2540 Bad Vöslau, Vienna.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bugnyar
authors.affiliation: Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria.|Haidlhof Research Station, University of Vienna and University of Veterinary Medicine, 2540 Bad Vöslau, Vienna.
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Reber
authors.affiliation: Department of Philosophy, University of Houston, 4300 Calhoun Road, Houston, Texas 77004, USA.
authors.forename: Cameron
authors.initials: C
authors.lastname: Buckner
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D003163:Competitive Behavior / Q000502:physiology*; D046368:Crows; D005260:Female; D005793:Generalization, Psychological; D008297:Male; D056345:Theory of Mind / Q000502:physiology*; D014796:Visual Perception
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