Abstract
In my experiment I studied domestic chicks (Gallus gallus domesticus) to find out how different sounds and colours affect their behaviour in a feeding process. Previous studies have found the wasp’s buzzing to be a negatively associated sound, triggering innate biases and increase learning speed. Hen cluck is found to be a positively related sound to chicks, uttered by a maternal hen to attract her chicks to the food. In my experiment I performed a 12-trial discrimination-learning task on inexperienced chicks, serving them mealworms combined with a visual signal (yellow, green or brown colour) and a sound signal (no sound, buzzing or hen cluck). Half of the prey was manipulated and unpalatable and the other half were palatable with neutral brown colour. The aim of these trials was to test whether there are innate biases toward these signals and how they affect the speed of aversion learning. I found that buzzing sound triggered an innate bias against novel prey in the first trial. In the aversion trials I found great differences between how the hen cluck affected the chicks served yellow prey and chicks served green prey. Among chicks served green prey the hen cluck group attacked most prey, while this effect was the opposite among the chicks offered yellow prey. The innate fear of yellow may have overshadowed the hen cluck as a positive signal. The yellow colour was also found to be the best cue to distinguish between the unpalatable and palatable prey. Chicks offered brown mealworms, with sound as the only distinguishing cue did not learn to distinguish between the unpalatable and palatable prey. Obviously, sound alone was not enough to learn the task. Three extinction-learning trials where also performed to study how memorable the signals were to the chicks. Higher memorability was shown for groups receiving hen cluck as part of their treatment. This is to my knowledge a new theory, ready to be further investigated and hopefully confirmed.