The role of differential reinforcement in predator avoidance learning

Little is known about how predator recognition develops under natural conditions. Predispositions to respond to some stimuli preferentially are likely to interact with the effects of experience. Convergent evidence from several studies suggests that predator-naïve tammar wallabies (Macropus eugenii) have some ability to respond to vertebrate predators differently from non-predators and that antipredator responses can be selectively enhanced by experience. Here, we examined the effects of differential reinforcement on responses to a model fox (Vulpes vulpes), cat (Felis catus) and conspecific wallaby. During training, tammars experienced paired presentations of a model fox and a simulated capture, as well as presentations of a wallaby and a cat alone. Training enhanced responses to the fox, relative to the conspecific wallaby, but acquired responses to the two predators did not differ, despite repeated, non-reinforced presentations of the cat. Results suggest that experience interacts with the wallabies' ability to perceive predators as a natural category.