FeathersPsittaciformesEstradiolbeta-KeratinsCorpus LuteumProgesterone CongenersBirdsMifepristoneProgestinsEstrusParrotsLuteinizing HormoneMoltingBeakBird DiseasesUterusPregnancyOvariectomyLuteal PhaseIntegumentary SystemPigmentationPregnancy, AnimalOvulationEndometriumReceptors, EstrogenOvaryHormone AntagonistsPasseriformesEstrogensDinoprostMenstrual CycleChickensHydroxyprogesteronesDinosaursLuteal CellsPseudopregnancyColorChorionic GonadotropinFollicle Stimulating HormoneFossilsGonanesGonadal Steroid HormonesGranulosa Cells20-alpha-DihydroprogesteroneChick EmbryoFlight, AnimalOvarian FollicleSheepNorpregnadienesOviductsSteroidsPhthirapteraEstrous CycleFollicular PhaseLuteolysisCastrationCattleSongbirds