An integrative approach to the study of ‘theory-of-mind’-like abilities in ravens

抄録

Due to new impressive results in primates and even non-primates such as dogs, dolphins, and corvids, the question whether or not non-human animals possess elements of a ‘Theory of Mind’ (ToM) has recently gained momentum. Indeed, attempts have been put forward to test species with ecologically relevant tasks, leading to the development of new test paradigms, such as the competitive conspecific or ignorant helper, and to run controls for behaviour-based alternatives. I here argue for strengthening this integrative approach and present preliminary data from our model system, the common raven Corvus corax. Based on observations of tactical manoeuvres of wild and captive ravens during foraging, we have tested the ability of hand-raised birds to differentiate between conspecifics that do and do not know about cache locations because they have or have not been able to see the caches being made. In addition to this version of guesser-knower experiments, we have been investigating (i) if the birds' performance is affected by the manipulation of observable cues, (ii) how likely the performance can be achieved by attending to observable cues, (iii) how flexibly birds can apply their skills across contexts, (iv) how the skills develop during ontogeny and (v) how they are affected by experience. The potential implications of incorporating tests for behavioural cueing and learning as well as the issues of ontogeny and flexibility to studies on ToM are discussed.