The Effect of Sounds on Domestic Hens' Behaviour Under Concurrent and Concurrent-chain Schedules

The effect of various sounds on the behaviour of domestic hens was examined. The effect of white noise on hens' performance under multiple-concurrent schedules was compared with the effects of an alarm call, the sounds of hens feeding, and a food call. All sound biased hens' responding away from keys associated with them, and the magnitude of this bias was largest for white noise and the food call. White noise suppressed the responding of hens when it was present, however, the other sounds did not. Next, a concurrent-chains procedure was used to assess the same hens' preferences for the same sounds. In the equal initial-links (with no sounds played) hens chose between "sound" and "no sound" terminal-links. Initial-link response biases were away from the key associated with sound for the food call for all hens and the directions of the other biases varied over hens. Terminal-link entry pauses tended to be longer in terminal-links associated with sounds where the longest pauses were with white noise and the food call. Thus, the two procedures gave some similar and some conflicting results. The various measures of behaviour, including response biases, response rates, and terminal-link pauses, will be compared and discussed.