Stahlbaum C C, Rovee-Collier C, Fagen J W, Collier G
Physiol Behav. 1986;36(4):751-8. doi: 10.1016/0031-9384(86)90364-1.
Twenty-four-hr patterns of running wheel activity (Experiment 1) and death feigning, an antipredator behavior (Experiment 2), were studied in domestic chicks housed outside, in natural lighting, or indoors, with light onset and offset timed to coincide with the upper limbs of local sunrise and sunset, respectively. Although chicks housed outside were more active and displayed stronger death feigning reactions, the daily patterns of each activity were highly similar in the two groups. Activity peaked during the period corresponding to evening twilight and was negligible during the morning twilight period; in contrast, death feigning peaked during the morning twilight period. Activity measures indicated that chicks on the artificial light schedule had learned to anticipate dark by day 5, and subsequent ontogenetic changes in activity occurred exclusively in the evening twilight phase.
研究了家鸡在室外自然光照条件下或室内（光照开始和结束时间分别与当地日出和日落的上边缘时间一致）的24小时转轮活动模式（实验1）和假死行为（一种反捕食行为，实验2）。尽管室外饲养的小鸡更活跃，表现出更强的假死反应，但两组中每项活动的每日模式高度相似。活动在对应于傍晚暮色的时间段达到峰值，而在早晨暮色期间可忽略不计；相反，假死行为在早晨暮色期间达到峰值。活动测量表明，按照人工光照时间表饲养的小鸡在第5天时已经学会了预期黑暗，随后活动的个体发育变化仅发生在傍晚暮色阶段。
