Repeated exposure of the domestic chick to a novel environment: Effects on behavioural responses.

Seven-day-old male and female chicks of three strains were placed individually in an open field or novel environment for 15-min periods; this procedure was repeated daily for four consecutive days. Several behavioural characteristics were recorded and the magnitude and direction of any changes in the characteristics with repeated exposure were analysed. Significant decreases over time were observed in the following characteristics: latency to the first step, duration of freezing, sitting time, lying time, eye-closure and head-shaking, whereas significant increases with repeated testing were recorded for distress calling, number of steps taken, walking time, pecking, preening and jumping. No significant changes were observed in defaecation, standing time, bill opening or scratching the litter. The results are discussed in terms of the measurement of fearful behaviour under the assumption that experience in a novel environment may act to reduce the level of fear associated with that situation.