Gonadal Hormones And Mating Strategies Of Female Golden Snub-nosed Monkeys (Rhinopithecus Roxellana) In Qinling Mountains

Mating and reproduction are the way to expand fitness of individuals and the amounts of population.We can have a better understanding of species by studying reproductive behaviors and the inner endocrine mechanism.It can also do good to protection of endangered animals.As an endangered species,Rhinopithecus roxellana will be in better preservation if we thoroughly realize their mating behaviors and some other concerned staff.Mating behaviors in two one male units were recorded by focal unit sampling and all-occurrence recording,and fecal samples of all focal individuals were collected from September 2015 to January 2016 and March 2016 to June 2016.We used enzyme linked immunoassays to measure the estradiol,progesterone and testosterone of adult females.Results suggested that estradiol and progesterone contents of non-breeding females had cyclical fluctuations in both mating season and breeding season(the mean time length of menstrual cycles= 24.3±2.3 d,n=12).These contents were high in mating season than in breeding season(mating season:E2:80759.30±24658.55 pg/g,n= 216;P:94.45±63.88 ng/g,n= 231.Non-mating season:E2:74417.43±11163.95 pg/g,n= 120;P:65.12±38.79 ng/g,n= 105).Breeding members got much more high gonadal steroid contents when they were pregnant,but dropped to a low level after giving birth to infants.Their solicitation behaviors in both units were imitated more often than non-breeding members(Mann-Whitney U test:WF:U=8586,P<0.01;SQ:U=6626,P<0.01)and they still solicited resident male in pregnancy.Individuals with low gonadal steroid contents in the whole mating season are of less proceptivity than those who are ready to conceive.Mating competition is hence decreased.Testosterone may affect the proceptivity of female snub-nosed monkeys to a certain degree.