Shyness and boldness in greater rheas Rhea americana Linnaeus (Rheiformes, Rheidae): the effects of antipredator training on the personality of the birds

The shy-bold continuum is an axis of behavioural variation for some species, but the consequences of shyness and boldness in antipredatory behaviour is unknown. Bold animals have the tendency to be predated first after release in comparison to shy animals, who naturally avoid the predators. Antipredatory training has been used to enhance the defence behaviours of naive animals by various researchers around the world. For greater rheas, Rhea americana (Linnaeus, 1758), this kind of study is pioneer. In this study we have investigated if there are relationships between personality and performance of greater rheas in antipredatory training. We also investigated if the training procedures influenced the behaviour of the birds when presented to novel objects. Fifteen zoo-borne greater rheas were studied and 16 personality tests were run, being eight before the application of antipredator training, and eight after the training. We presented to the birds four novel objects (ball, box, bag and person) and recorded their behaviour and the distance of the birds in relation to the objects. Results showed that the birds behave boldly before training and shyly after it. The antipredator training modified significantly the behaviour of the rheas, making them more careful about novel situations. Personalities affected the behaviour of the birds during antipredator training. The study of the animal personalities can be an useful tool in reintroduction programs since it helps to choose the animals with the highest chance of survival to reintroduce. O contínuo timidez-coragem é um eixo de variação comportamental para algumas espécies, mas as conseqüências da timidez e coragem no comportamento anti-predação não são conhecidas. Animais corajosos tendem a ser predados primeiramente após a reintrodução em comparação com os animais tímidos, que naturalmente evitam os predadores. O treinamento anti-predação tem sido usado para aumentar os comportamentos defensivos de animais nascidos em cativeiro por vários pesquisadores ao redor do mundo. Para emas, Rhea americana (Linnaeus, 1758), este tipo de estudo é pioneiro. Neste estudo, foi investigado se existe relação entre a personalidade e a performance das emas no treinamento anti-predação. Também foi investigado se o treinamento influencia o comportamento das aves quando apresentadas a novos objetos. Foram estudadas 15 emas nascidas em cativeiro, através de 16 testes de personalidade, sendo oito antes da aplicação do treinamento ant