Rhythms, reproduction, and photoreception.
D000818:Animals; D001683:Biological Clocks; D001717:Birds; D001831:Body Temperature; D001835:Body Weight; D001921:Brain / Q000502:physiology; D002940:Circadian Rhythm; D003624:Darkness; D004777:Environment; D005260:Female; D005523:Food Supply; D008027:Light; D008297:Male; D009929:Organ Size; D010786:Photoreceptor Cells / Q000502:physiology*; D010870:Pineal Gland / Q000502:physiology; D012098:Reproduction; D012160:Retina / Q000502:physiology; D012621:Seasons; D012726:Sexual Behavior, Animal; D013737:Testis / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology; D013997:Time Factors