Several neo-tropical butterfly species were presented to 171 wild-caught adult Blue Jays to determine if insects of unfamiliar color pattern would elicit an attack response from an avian predator regardless of the visual characteristics of the prey. It was found that unfamiliar insects do not always elicit an attack response. Four aspects of the birds' behaviors were noted: 1) the initial responses to various training diets were different; 2) the training diets had a direct effect on the reactions of the birds to new insects; 3) there was a difference in the attack responses of the birds to different novel insects; 4) there was an interaction between training diets and novel insects. Four aspects of avian feeding behavior were discussed as possible explanations of the results: preference for familiar food, generalization from previous experience, innate avoidance of specific stimuli, and innate avoidance of novel stimuli.
