Behavioural persistence in captive bears and its implication for reintroduction success
We investigated the relationship between stereotypic behavior and abnormal behavioral persistence,a trait that could have potentially negative implications for reintroduction efforts, for 18 Asiatic black bears (Ursus thibetanus) and 11 Malayan sun bears (Helarctos malayanus) individually housed in a government confiscation facility in Thailand. Reintroduction or augmentation programs using captive-reared animals are typically less successful than those involving wild-reared con-specifics. One reason for this may lie in deficiencies in the behavior of captive animals. Attributes of stereotypy performance were quantified by observing bears from blinds. Mean stereotypy frequencies ranged between 0 and 51% (mean = 18%, SE = ±3), of all observations, and stereotypy frequency increased with age. To assess behavioral persistence, 12 bears were trained in a spatial discrimination task; once a performance criterion had been met, further responses were unrewarded and the ability to cease responding was assessed. The number of trials for which bears continued responding without reward was positively related to stereotypy frequency. This finding suggests that captivity can exert subtle but potentially detrimental influences on behavioral control that could possibly be manifest even in non-stereotypic animals. In the wild, where behavior must be adaptive and flexible to meet fluctuating conditions, such behavioral deficiencies could help account for reduced survivorship of reintroduced subjects.