Study On The Relationship Between Sex Hormone Levels And Reproductive Behavior Of A Provisioned Female Yunnan Snub-nosed Monkey Group

Reproductive behavior has always been an important part of zooecology ecology feilds.To explain the reproductive behavior strategies adopted by animals,Zoologists have proposed relevant ecological hypotheses,such as female active invitation hypothesis,breeding seasonal hypothesis,etc.Sex hormones are closely related to the reproductive behavior of animals,which can lead to the reproductive system and regulate their reproductive function of animals,therefore the reproductive physiology hypothesis have also proposed by Zoologists to try to explain this phenomenon.Yunnan Snub-Nosed Monkey,is distributed the highest altitude among non-human primate in the world.which belongs to seasonal breeding animals.Due to the inconspicuous redness and swelling of the sex skin during the breeding period,and the changes in the abdomen after pregnancy are not prominent,aditionally,the habitat of Yunnan Snub-Nosed Monkey is complicated,which has led the studies of the reproductive physiology of the species is relatively lagging behind.The research on the reproductive physiology of Yunnan Snub-Nosed Monkey is mainly based on caged objects,and there are few studies on wild monkeys;the research results only stay in the status of presumed ovulation period,conception date and delivery date;there are little known for differences in sex hormone levels among different reproductive status,different primipara and different non-prime groups;there are no reports of differences in sex hormones at different reproductive stages.The trends of sex hormones in different physiological states and different periods may vary among different primate species,and if their sexual behaviors are related to sex hormones is yet to be verified.Compared with a large number studies of sex hormones on Rhinopithecus roxellana,as neighbor in the taxonomic,Yunnan Snub-Nosed Monkey has still a long way to go in the sex hormone research.Based on this,in order to understand the changes of sex hormones throughout the year,the differences of hormones in different reproductive states and different reproductive stages,and whether the sexual solicitations behaviors are related to sex hormones,and further insight into the breeding strategy of female Yunnan Snub-Nosed Monkey,during the period from June 2016 to August 2017,we conducted a full-year monitoring of sex hormone levels and invitation behaviors of a provisioned female Yunnan Snub-Nosed Monkey group of the Baimaxueshan National Protected Area.The main studies contents and results are as follows:1.By comparing the sex hormones of female Yunnan Snub-Nosed Monkey in different fertile stages and different reproductive stages of two fertile stages,the results showed that Estradiol(E2)and Progesterone(P4)in the fertility group and non-fertility were significantly different in the whole year,breeding period and pregnancy period.The E2 and P4 levels in the fertile group were the highest during pregnancy,more lower before pregnancy,the lowest in lactation,indicating that E2 and P4 are extremely important for maintaining copulation,pregnancy,and reproductive behavior in female monkeys.Female monkeys maximize their reproductive benefits by regulating sexual reproduction in their body by sex hormones.The results of this study support the reproductive physiology hypothesis.2.By comparing the sex hormones in different reproductive stages of the primiparous and non-primiparous groups of female monkeys,the results showed that the level of E2 in the primiparous group was significantly higher in the gestational period than in the non-primiparous group;the age of the primiparous group in the female monkey,we presumed that the age may be the main reason for the significant difference in the level of E2 between the primiparous group and the non-primiparous group,the reason is that the change pattern of E2 in female monkeys is consistent with the female human beings,which changes of E2 in mid-peak mode cross whole developmental stages.3.The analysis of the sexual solicitations behavior of female monkeys showed that the sexual solicitations of 6 female monkeys was concentrated in July,August and September.The behavior match to the maximum temperature,food supply period and peak rainfall period,which also related to ensuring the rich food supply when the baby monkey is born,our results are consistent with the breeding seasonal hypothesis.4.Correlation analysis between the sexual solicitations behavior and sex hormones showed that the sexual solicitations was significantly correlated with E2 during the breeding period.After into the pregnancy,there was still an sex behavior,but it was significantly lower than the breeding period.The correlation test showed that there is no correlation between the two in pregnancy period;the sexual solicitations behavior is not related to P4 during the breeding and non-breeding period,which is mainly affected by E2 in the menstrual cycle.The sexual solicitations behavior is more determined by the community environment during the non-breeding period,which is more related to the consolidation of reproductive relationships and other social functions.