The relative roles of diurnal periods of activity and diurnal photoperiods in gonadal activation in male Zonotrichia leucophrys gambelii (Nuttall).
D000818:Animals; D001717:Birds; D006066:Gonads; D006801:Humans; D008297:Male; D017440:Photoperiod; D013737:Testis / Q000502:physiology*
BIRDS; TESTES/physiology