Operant conditioning in the newly hatched chicken.

Techniques are described for conditioning key-pecking reinforced with food and for recording cheeping in newly hatched chickens. A mirror in the test box is essential when conditioning isolated chickens up to five or more days old. Conditioning proceeds more rapidly when frequently pecked objects and materials that move when scratched are not present. Stimulus control over key-pecking is present in the three-day-old chicken and multiple fixed-ratio, fixed-interval schedule control develops in succeeding days. In young chickens, pecking and cheeping are inversely related. The newly hatched chicken is useful for pharmacological studies and appears to offer other advantages for behavioral studies.