Periodicity of death feigning by domestic fowl in response to simulated predation.

The presence and extent of periodicity in the manifestation of death feigning duration was assessed in 137 week-old White Leghorn chicks. Chicks were reared on an LD 12:12 regimen with light onset at 0800 hr. Each was tested only once at one of 13 clock hours spanning a 24 hr period. Death feigning duration varied significantly with clock hour of induction, being longest from 1300-1400 hr and briefest from 0600-1100 hr. Variability was also cyclic but was distributed bimodally, being greatest in the latter half of each L and D phase. There was no significant influence of management hour on death feigning duration. The adaptive significance of the periodicity for predator-prey interactions was discussed, as were methodological implications.