Accessory reproductive organs of male fringillid birds:  seasonal variations and response to various sex hormones.
D000818:Animals; D001717:Birds; D005835:Genitalia; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D008297:Male; D012098:Reproduction; D012621:Seasons
D012739:Gonadal Steroid Hormones
BIRDS; GENITALIA; SEX HORMONES/effects