Responses of Chicks To Brightly Coloured Insect Prey

In experiments 1 to 3, domestic chicks that had not previously been fed were given a choice between olive-green painted mealworms and mealworms that were painted with single colours (black, yellow or red), stripes of alternating colours (black-and-yellow, black-and-red or yellow-and-red) or half one colour and half another (black-and-yellow, black-and-red or yellow-and-red). Relative to olive-green mealworms, chicks showed a strong aversion to black prey, a milder aversion to black-and-yellow striped prey, and a marginal aversion to red prey. All other colours and patterns were either neutral or preferred. We conclude that neither striped prey nor unstriped bicoloured prey are necessarily more aversive than prey of a single colour, and that the results are best explained in terms of specific aversions to certain colours and patterns, rather than to some general feature of the prey such as novelty or contrast. Experiment 1 also showed that rearing chicks in black-and-yellow cages reduced or reversed their aversion to black-and-yellow striped and black prey, and increased their preference for yellow and bicoloured prey. We conclude that while preferences and aversions towards prey of these colours are unlearned their development can be affected by experience. Experiment 4 showed, using a one-trial learning procedure, that prey colour (black-and-yellow striped, black, yellow or bicoloured) did not significantly affect the strength of avoidance learning when the prey was distasteful. We conclude that unlearned preferences and aversions for particular prey do not interact with the effectiveness of avoidance learning.