Circadian involvement in termination of the refractory period in two sparrows.
Endogenous daily rhythmicity is involved in the short-day photoperiodic response of breaking the refractory period in both white-crowned and golden-crowned sparrows. Under a modified "coincidence model," short-day photoperiodic induction occurs when light is noncoincident with a specific phase of an internal rhythm.
D000818:Animals; D001717:Birds; D002940:Circadian Rhythm; D008027:Light; D008297:Male; D010507:Periodicity; D012098:Reproduction; D013737:Testis / Q000502:physiology*