Abstract # 2737 Event # 180:

Scheduled for Monday, September 21, 2009 10:00 AM-10:10 AM: Session 16 (Mission Bay Ballroom AB) Oral Presentation


B. Wallner1, D. Aspernig2 and I. H. Machatschke3
1Department of Anthropology, University of Vienna, Vienna, Austria, 2Institute of Biochemistry, Veterinary University of Vienna, 3Department of Behavioural Biology, University of Vienna

During the estrus cycle, females of some macaque species change the color intensity of their secondary sex characteristics. These changes are dependent on fluctuating sex-steroids. The steroid estradiol seems to be responsible for intensifying the coloration whereas increased progesterone concentrations affect the reverse. Generally, the strength of coloration seems to be correlated with sexual attractivness. Japanese macaques are seasonal breeders. During the sexual active phase, females show increased redness of face, anogenital region and mammillae. The aim of our study was to investigate whether the color intensity of these regions was different, retrospectively analyzed during sexual inactive (SI) and active periods (SA) between females with reproductive success and those without. The redness scores of 19 adult females were classified by using color tables. Sex steroids were determined in fecal samples. During SI and SA, prospective mothers [N=12] showed increased redness of the anogenital region and the mammillae [Mann-Whitney U test, p<0.01], but not for the face compared to females who did conceive. Endocrinologically, mothers had decreased progesterone und increased estradiol levels during SI. Throughout SA, concentrations of both sex-steroids were elevated corresponding to levels of fertilized females [Mann-Whitney U test, p<0.001]. The results of this work indicate that during SI, increased sexual attractiveness, as advertised by more intense redness, is related to sex steroids and ultimately results in reproductive success after SA.