Photoreception in sparrows: response to photoperiodic stimuli.
D000818:Animals; D001717:Birds / Q000502:physiology*; D001766:Blindness; D008027:Light; D008297:Male; D009929:Organ Size; D010507:Periodicity; D011336:Probability; D011830:Radiation Effects; D013737:Testis / Q000033:anatomy & histology*