Learning specificity in acquired predator recognition

Predator recognition is often dependent upon experience. This behavioural plasticity can potentially be exploited to enhance the antipredator behaviour of captive-bred animals, but it is first necessary to understand the specificity of learning. We enhanced the responses of tammar wallabies, Macropus eugenii, to a model fox, Vulpes vulpes, by presenting this novel predator in conjunction with a human simulating a capture procedure. A control group had identical total exposure to fox and human, but with no such predictive relationship between these two events. Animals that experienced paired presentations of fox and human behaved more cautiously towards the fox after training than controls. To assess whether this learnt response was specific to the fox, we presented the animals with an array of visual stimuli both before and after training. The tammars generalized their acquired response from the predator with which they were trained to a predator with which they were not trained (cat, Felis catus), but not to a nonpredator (goat, Capra hircus). Tammars also exhibited a transient increase in response to a model wallaby after training. We suggest that this effect is more likely to reflect social behaviour than generalization of the learnt response from predator to conspecific. Two additional controls revealed that changes in behaviour after training were not attributable to the presentation device and were not caused by a general decrease in response threshold associated with training. Our results suggest that tammar wallabies perceive predators as a natural category.