title: A Bruce effect in wild geladas.
abstract: Female rodents are known to terminate pregnancies after exposure to unfamiliar males ("Bruce effect"). Although laboratory support abounds, direct evidence for a Bruce effect under natural conditions is lacking. Here, we report a strong Bruce effect in a wild primate, the gelada (Theropithecus gelada). Female geladas terminate 80% of pregnancies in the weeks after a dominant male is replaced. Further, data on interbirth intervals suggest that pregnancy termination offers fitness benefits for females whose offspring would otherwise be susceptible to infanticide. Taken together, data support the hypothesis that the Bruce effect can be an adaptive strategy for females.
authors.affiliation: Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Eila K
authors.initials: EK
authors.lastname: Roberts
authors.forename: Amy
authors.initials: A
authors.lastname: Lu
authors.forename: Thore J
authors.initials: TJ
authors.lastname: Bergman
authors.forename: Jacinta C
authors.initials: JC
authors.lastname: Beehner
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001522:Behavior, Animal; D001723:Birth Rate; D004967:Estrogens / Q000032:analysis; D005002:Ethiopia; D005243:Feces / Q000737:chemistry; D005260:Female; D056084:Genetic Fitness; D005865:Gestational Age; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D011270:Pregnancy, Animal; D012726:Sexual Behavior, Animal; D012919:Social Behavior; D012930:Social Dominance; D016671:Theropithecus / Q000502:physiology / Q000523:psychology
chemical_list: D004967:Estrogens