title: Fatal sibling aggression, precocial development, and androgens in neonatal spotted hyenas.
abstract: Fatal neonatal sibling aggression is common in predatory birds but has not been previously reported in wild mammals. Spotted hyena females are strongly masculinized, both anatomically and behaviorally, apparently by high levels of androgens during ontogeny. Neonates display elevated androgen levels, precocial motor development, and fully erupted front teeth. Litters are usually twins, and siblings fight violently at birth, apparently leading to the death of one sibling in same-sex litters, whereas in mixed-sex litters both siblings usually survive.
authors.affiliation: Department of Psychology, University of California, Berkeley 94720.
authors.forename: L G
authors.initials: LG
authors.lastname: Frank
authors.forename: S E
authors.initials: SE
authors.lastname: Glickman
authors.forename: P
authors.initials: P
authors.lastname: Licht
mesh_terms: D000374:Aggression / Q000502:physiology*; D000728:Androgens / Q000097:blood*; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D002335:Carnivora / Q000502:physiology*; D003817:Dentition; D005260:Female; D008297:Male; D009043:Motor Activity / Q000502:physiology; D012727:Sex Characteristics; D012744:Sex Ratio; D012801:Sibling Relations; D014078:Tooth Eruption / Q000502:physiology
chemical_list: D000728:Androgens