Lateralization in spatial orientation and self-recognition in tortoises (Testudo hermanni)

Cerebral lateralization is a widespread phenomenon among vertebrate species, such as mammals, birds, amphibians and fishes (for a review, see Rogers & Andrew, 2002). Interestingly, some forms of perceptual lateralization seem to be strictly linked to the social environment. For example, birds (Daisley et al., 2009) and fishes (Sovrano et al., 1999; De Santi et al., 2000; Bisazza et al., 2003) tend to observe their conspecifics using preferentially the left eye, suggesting that the contralateral right hemisphere seems to be specialized in the processing of social stimuli. So far, few researches have involved Reptiles in the investigation of cerebral asymmetry and, among these, only one has focused on the group of Chelonia, in which a preference to re-set the posture upwards with the right forelimb was found (see Stancher et al., 2006). The aim of this study is to test whether non-social species, such as Chelonians, manifest lateralized behavioural responses in relation to the social environment. Moreover, we observed whether a non-social task, such as spatial orientation, is likely to elicit a different lateralized behaviour.