A simple method for testing odor detection and discrimination in chicks

A simple procedure for testing newly hatched chicks' responses to olfactory stimuli is described. Chicks that were hand held under a heatlamp became i nactive and closed their eyes (as if asleep) within 2 min. Sleeping chicks displayed overt behavioral responses to an odorized q-tip (head shaking, be ak clapping) that were not observed in awake chicks. Sleeping latencies wer e shorter for 1-day-old chicks that had been food deprived prior to testing than for chicks that had ad lib access to food and water. When airborne od ors were presented by squeezing a soft plastic odor bottle near the beak, s leeping chicks' reactions to mint were of a greater magnitude than their re sponses to lavender or orange scents. Nonetheless, all three odors elicited more pronounced behavioral responses than did the water control stimulus. This method allows rapid testing of individual chicks for odor detection an d discrimination. (C) 1999 Elsevier Science Inc.