title: An oestrogen-mediated effect of photoperiod on the reproductive behaviour of the budgerigar.
mesh_terms: D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D008027:Light; D011563:Psittaciformes / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000187:drug effects*
chemical_list: D004958:Estradiol