Colour counts: Effects of aposematic colouration in chick learning

Abstract

Much has been written about the effects of bead colour and sheen on the consolidation of one-trial passive avoidance learning tasks in day-old chicks. Laboratories have adopted a variety of training procedures using beads of varying sizes, colours and textures. We were interested in whether beads with aposematic colouration (bright 'warning' colouration) would alter memory consolidation of the weaker form (10%MeA) of passive avoidance learning in chicks. Thus, day-old chicks were trained and tested using the standard Open University, UK protocol on the 'weaker' form of the task, but using beads that were chrome, black, yellow or black-and-yellow stripes. Chicks tested 24hr following training with either chrome, black or yellow beads showed no avoidance of the training bead, whereas chicks trained on the black and yellow striped bead showed high levels of avoidance (and significant discrimination ratios) at test. These data, together with data from experiments in which chicks were all trained with the black-and-yellow striped bead and tested with either a black, yellow, chrome or black-and-yellow striped bead suggest that bead colouration, specifically aposematism, is a significant factor in the salience and thus recall of this task.