Animal behaviorists involved in the introduction of captive-bred endangered species have long recognized the need for pre-release training in various elements of survival such as finding food and shelter. Recently, New Zealand researcher Ian McLean has united academic and agency biologists in efforts to demonstrate how naive wild and captive animals can be taught to recognize and avoid predators simply, quickly, and economically enough to be part of every introduction program. The conditioning of animals to avoid predators highlights the importance of an ethological perspective in appreciating the necessary stages and likely pitfalls of the task. The research also provides opportunities to test hypotheses about the extent to which anti-predator behavior is learned in species with different social systems, habitats, and degrees of 'evolutionary exposure' to various predation strategies.

The rufous hare-wallaby (Lagorchestes hirsutis) went extinct in mainland Australia in 1991 but persists today on two islands and in captivity. The species decline is attributed to a combination of human disturbance, introduced predators (foxes and cats), and ill-timed droughts. Despite intensive predator control at release sites, initial releases of the species failed quickly due to predation. McLean et al. (1996) showed that hare-wallabies responded warily (staying out of sight, increasing vigilance) when novel stimuli were placed in their enclosures, particularly fox and cat models, suggesting an innate avoidance of unknown animals that could be, and was, accentuated by training. Successful training involved 1) the sudden bursting of the model predator from a box in association with a loud noise and recordings of hare-wallaby alarm calls or 2) a model that 'lept' at hare-wallabies as they approached and a simultaneous squirt from a water gun.

A less encouraging result was the apparent loss of memory of the model after several months. This raises the interesting question of how frequent and intense predator encounters must be in the wild for learned avoidance to be maintained - and the role of a critical period for the development of stronger associations. Similar questions are addressed in studies that show how anti-predator behaviors are lost in wild populations of prey animals in places where large predators have been extirpated (Berger 1997).

McLean et al. (1999) conducted a similar study in a wild population of the New Zealand Robin, as a surrogate for the endangered Black Robin. Conditioning involved free-ranging young birds 1) watching a predator model 'leap' at their foraging parents while alarm calls were played and/or 2) being detained in an aviary and exposed to the lunging model and alarm calls themselves. Conditioned birds were less likely (longer latencies and refusal) to retrieve food placed on the back of a predator model than naïve birds were. Studies with more realistic models and live predators (rendered harmless) are ongoing.

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Berger, J. 1997. Future prey: Some consequences of the loss and restoration of large carnivores. In: Caro, T. (ed.). Behavioral Ecology and Conservation Biology. Oxford University Press, Oxford. pp. 80-100.

McLean, I.G. 1997. Conservation and the ontogeny of behavior. In: Clemmons, J. R. and Buchholz, R. (eds.), Behavioral Approaches to Conservation in the Wild. Cambridge University Press, Cambridge. pp. 132-156.

McLean, I.G., Holzer, C., and Studholme, B. J. S. 1999. Teaching predator-recognition to a naive bird: implications for management. Biological Conservation 87: 123-130.

McLean, I. G., Lundie-Jenkins, G, and Jarman, P. J. 1996. Teaching an endangered mammal to recognise predators. Biological Conservation 75:51-62.

McLean, I. G. and Rhodes, G. I. 1991. Enemy recognition in birds. Current Ornithology 8: 173-211.