title: Female behavioral proceptivity functions as a probabilistic signal of fertility, not female quality, in a New World primate.
abstract: The interests of males and females in mating contexts often conflict, and identifying the information conveyed by sexual signals is central to understanding how signalers manage such conflicts. Research into the information provided by female primate sexual signals has focused on exaggerated anogenital swellings as either reliable-indicators of reproductive quality (reliable-indicator hypothesis) or probabilistic signals of fertility (graded-signal hypothesis). While these morphological signals are mostly confined to catarrhine primates, these hypotheses are potentially widely applicable across primates, but have not been tested in taxa that lack such morphological signals. Here, we tested these hypotheses in wild black capuchins (Sapajus nigritus), a species in which females lack morphological sexual signals but produce conspicuous behavioral estrous displays. Specifically, we examined the proportion of time different females spent producing these signals with respect to measures of female quality (dominance rank, parity, age-related fecundity and cycle type) and in relation to the timing of fertility, as determined by analysis of fecal progesterone. Time spent displaying did not vary across females based on measures of female quality, but increased with the approach of ovulation. Further, male mating effort varied according to the timing of female fertility. Proceptive behaviors in this species thus meet predictions of the graded-signal hypothesis, providing the first support for this hypothesis based solely on behavioral signals.
authors.affiliation: Cognitive Ethology Laboratory, German Primate Center, Goettingen, Kellnerweg 4, 37077, Germany; Courant Research Centre "Evolution of Social Behaviour", University of Goettingen, Goettingen, Kellnerweg 7, 37077, Germany; Instituto de Biologia Subtropical, Universidad Autonoma de Misiones, Puerto Iguazú, Bertoni 85, 3370, Argentina. Electronic address: batiddi@gmail.com.
authors.forename: Barbara
authors.initials: B
authors.lastname: Tiddi
authors.affiliation: Cognitive Ethology Laboratory, German Primate Center, Goettingen, Kellnerweg 4, 37077, Germany; School of Anthropology & Conservation, University of Kent, Canterbury, United Kingdom.
authors.forename: Brandon C
authors.initials: BC
authors.lastname: Wheeler
authors.affiliation: Endocrinology Laboratory, German Primate Center, Goettingen, Kellnerweg 4, 37077, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Heistermann
mesh_terms: D000818:Animals; D002428:Cebus / Q000502:physiology / Q000523:psychology; D003463:Cues; D005260:Female; D005298:Fertility / Q000502:physiology*; D008297:Male; D010060:Ovulation / Q000502:physiology; D011323:Primates / Q000502:physiology / Q000523:psychology; D011336:Probability; D011374:Progesterone / Q000097:blood; D012098:Reproduction / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012930:Social Dominance
chemical_list: D011374:Progesterone
keywords: Graded-signal hypothesis; Multimodal communication; Non-invasive endocrinology; Proceptive behaviors; Reliable-indicator hypothesis; Sapajus nigritus