The response of willow grouse chicks to auditory stimuli 1. Preference for hen grouse calls.

Willow grouse (Lagopus lagopus lagopus) chicks newly hatched from mechanically incubated eggs were exposed to different combinations of sounds in a heated runway. They approached a loudspeaker playing grouse hen calls, which they had never heard, in preference to one playing the noise of the hatching machine from which they had just been removed. Similarly they preferred the hen call to another novel sound. When the three sounds were played singly instead of in pairs, only the hen call was approached.