title: Scent-marking and sexual activity may reflect social hierarchy among group-living male Mongolian gerbils (Meriones unguiculatus).
abstract: Social hierarchy plays an important role in the lives of gregarious species. We investigated how social hierarchy between male Mongolian gerbils (Meriones unguiculatus) housed together before sexual maturity affected their scent-marking behavior, endocrine status and physical traits as adults. The social rank between paired males was assessed based on sexual activity in adulthood at 18 and 20 weeks of age. In most cases, the male that showed higher sexual activity at 18 weeks also exhibited greater sexual performance at 20 weeks, suggesting a precedence relationship between paired males regarding reproductive opportunity. Sexually active males scent-marked more often than their cage mate, particularly after a sexual experience. No significant differences in physical traits (e.g., the weight of the ventral gland, testes and adrenal glands) or endocrine status (e.g., fecal testosterone and corticosterone levels) were found between the two males. These findings suggest that social rank between familiar males formed during cohabitation, and rank was closely correlated with scent-marking activity, but not with endocrine status.
authors.affiliation: Laboratory of Veterinary Ethology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Michito
authors.initials: M
authors.lastname: Shimozuru
authors.forename: Takefumi
authors.initials: T
authors.lastname: Kikusui
authors.forename: Yukari
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001835:Body Weight / Q000502:physiology; D003345:Corticosterone / Q000378:metabolism; D004291:Dominance-Subordination; D005243:Feces / Q000737:chemistry; D005260:Female; D005849:Gerbillinae / Q000502:physiology*; D006608:Hierarchy, Social; D007124:Immunoenzyme Techniques; D008297:Male; D009929:Organ Size / Q000502:physiology; D012543:Scent Glands / Q000737:chemistry / Q000502:physiology; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013731:Territoriality; D013737:Testis / Q000502:physiology; D013739:Testosterone / Q000378:metabolism
chemical_list: D013739:Testosterone; D003345:Corticosterone