title: Hormonal correlates of male attractiveness during mate selection in the mallard duck (Anas platyrhynchos).
abstract: The aims of the present study were (1) to examine if feeding condition prior to mating influences male hormone levels and behavior, (2) to evaluate the effect of age on male hormone levels, (3) to examine a possible association between male social display activity and four steroid hormones (testosterone, dihydrotestosterone, estrogen, and corticosterone), and (4) to examine if female behavior influences male hormone levels. Thirty male and fifteen female mallards were used in this study. Observations were made on a mixed flock of mallards for 10 consecutive days in autumn. Five weeks before the observations, males were randomly assigned to a feeding regime with either an unlimited food supply (UL group) or a limited food supply (L group). Males in the UL group showed significantly greater social display activity compared to the L group males. Females never incited (courted) males from the L group. Dihydrotestosterone levels were significantly higher in males showing social display activity as compared to males not showing these behavior patterns. Testosterone levels were significantly higher in males incited by females compared to males not incited by females.
authors.affiliation: Department of Zoology, University of Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Klint
authors.forename: L
authors.initials: L
authors.lastname: Edsman
authors.forename: K
authors.initials: K
authors.lastname: Holmberg
authors.forename: B
authors.initials: B
authors.lastname: Silverin
mesh_terms: D000367:Age Factors; D000818:Animals; D001143:Arousal / Q000502:physiology; D003345:Corticosterone / Q000097:blood; D003380:Courtship; D013196:Dihydrotestosterone / Q000097:blood; D004372:Ducks / Q000097:blood*; D004958:Estradiol / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D008297:Male; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013739:Testosterone / Q000097:blood
chemical_list: D012739:Gonadal Steroid Hormones; D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol; D003345:Corticosterone