Regulation Of Sex Hormones And Behavior On The Reproductive Strategies Of Wild Rhinopithecus Roxellana In Qinling Mountains

Among the social animals with seasonal breeding strategy,the intrasexual reproductive competition will be more intense because the mating behavior concentrated in a certain period.Therefore,animals maintain different reproduction strategies to adapt to the environment,which are usually regulated by behavior and endocrine.Golden snub-nosed monkeys(Rhinopithecus roxellana),a unique and endangered primates in China,are typical seasonal breeders which employed a polygamous system.Research on the regulation of the breeding strategy of golden snub-nosed monkeys can provide a scientific theoretical basis for the protection of this species.In this study,I used all occurrence sampling methods to collect the behavioral data,such as spatial proximity,grooming,and mating behaviors among two focus units in October to December of 2017 and March to June of 2018.I also used non-invasive method and Radioimmunoassay methods to measure the estradiol,progesterone and testosterone levels extracted from dry fecal samples of adult individuals in two one-male units according to different seasons and reproductive status.I explored how female individuals can regulate their reproductive strategies through behavioral and endocrine combinations in different physiological states in different seasons by combining behavioral and physiological approach.The results indicated that the levels of estradiol,progesterone and the frequency of solicitation among pregnant individuals(pregnancy group)in November and December were higher than unpregnant individuals(non-pregnant group).After giving birth in the next year,the hormone levels of pregnancy group members were returned to the normal contents of the non-pregnant group,and only the non-pregnant group members had mating solicitation behavior in spring.In the autumn and winter,the average testosterone cycle of all females was shorter than that in spring,the frequency of solicitations was correlated with testosterone in autumn and winter,and there was no correlation in spring.However,there was no inter-group difference or seasonal difference in the interaction and association between individuals.Females in the same unit may stagger the reproductive station and mating behaviors to adapt the seasonal changes in the environment and reduce the stress of intrasexual reproductive competition.Meanwhile,testosterone has a certain degree of influence on the mating behavior of females during the mating peak season.Meanwhile,the sex hormones did not have too much influence on the interaction and association of individuals.