title: Baby on board: olfactory cues indicate pregnancy and fetal sex in a non-human primate.
abstract: Olfactory cues play an integral, albeit underappreciated, role in mediating vertebrate social and reproductive behaviour. These cues fluctuate with the signaller's hormonal condition, coincident with and informative about relevant aspects of its reproductive state, such as pubertal onset, change in season and, in females, timing of ovulation. Although pregnancy dramatically alters a female's endocrine profiles, which can be further influenced by fetal sex, the relationship between gestation and olfactory cues is poorly understood. We therefore examined the effects of pregnancy and fetal sex on volatile genital secretions in the ring-tailed lemur (Lemur catta), a strepsirrhine primate possessing complex olfactory mechanisms of reproductive signalling. While pregnant, dams altered and dampened their expression of volatile chemicals, with compound richness being particularly reduced in dams bearing sons. These changes were comparable in magnitude with other, published chemical differences among lemurs that are salient to conspecifics. Such olfactory 'signatures' of pregnancy may help guide social interactions, potentially promoting mother-infant recognition, reducing intragroup conflict or counteracting behavioural mechanisms of paternity confusion; cues that also advertise fetal sex may additionally facilitate differential sex allocation.
authors.affiliation: National Evolutionary Synthesis Center, Durham, NC, USA Department of Integrative Biology, University of California, Berkeley, CA, USA Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.
authors.forename: Jeremy Chase
authors.initials: JC
authors.lastname: Crawford
authors.affiliation: Department of Evolutionary Anthropology, Duke University, Durham, NC, USA Department of Biology, Duke University, Durham, NC, USA cdrea@duke.edu.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Drea
mesh_terms: D000819:Animal Communication; D000818:Animals; D003463:Cues; D005260:Female; D005836:Genitalia, Female / Q000737:chemistry / Q000378:metabolism*; D007900:Lemur / Q000502:physiology*; D008297:Male; D009812:Odorants / Q000032:analysis*; D011247:Pregnancy / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D055549:Volatile Organic Compounds
keywords: chemosignal; gestation; hormone; olfactory communication; reproductive signal; sex allocation