CONICET | Buscador de Institutos y Recursos Humanos

Reintroduction of captive Greater Rhea can increase wild populations of the species; however, applying this strategy involves high post-release mortality due topredation. An anti-predator training of release candidates is a useful tool for them to recognize predators and be able to escape. The aim of this work was to evaluate the effectiveness of anti-predator training in captive Greater Rheas as well as post-release survival in the wild. Training involved 11 leg-banded individuals that were exposed to a stimulus representing the main wild predator (a taxidermized puma), followed by an aversive stimulus (simulated capture). The control stimulus was an object (a chair) that was harmless to the animal and not associated with the aversive stimulus. Each animal was submitted to five training sessions with each stimulus. Control Greater Rheas (nine individuals) were not exposed to either stimulus. All of the animals were exposed to the predator stimulus 30 and 60 days after the end of training. This stimulus was not paired with the aversive one so that behavioural responses could be compared. These data were collected using focal sampling with continuous recording. The aversive stimulus was unsuccessful, since there were no differences in vigilance and defense behavioural responses between groups. Eight months after release the trained animals did not show survival advantages with respect to controls, since survival was nil in both groups. Only one Greater Rhea was killed by a puma, whereas mortality of the remaining individuals was caused by predators not included in the training sessions, such as poachers and dogs (8 and 10 Greater rheas, respectively). The reasons for training inefficiency may have been the inclusion of only the principal wild predator of Greater Rheas as well as to a possible effect ofhabituation to humans during captivity.