Study On Mating Behavior And Sex Hormone Levels Of Artificial Auxiliary Food Provisioned Female Rhinopithecus Bieti

The reproductive behavior of primate is mainly determined by the estrus status of female, and it is an important approach to reveal the evolutionary development of the species through studying the reproductive behavior. Meanwhile, the level of sex hormone secretion directly reflects the reproductive status of animal, and it is an important means to explore the reproductive behavior by determining the sex hormones level of female.. Yunnan snub nosed monkey(Rhinopithecus bieti) is an endangered primate, and also endemic to China, living in the dense forest of high mountains. At present, there is still a lack of research on reproductive physiology. Therefore, from August 2014 to 2015 July, mating behaviors of 13 adult females in 5 OMUs of the artificial auxiliary food provisioned group were observed in Baima Snow Mountain National Nature Reserve throughout the year, using Ad libitum sampling and all occurrence recording methods, and the fecal estradiol(E2) and progesterone(P) level of female Rhinopithecus bieti in different seasons and under various physiological states were determined by chemiluminescent immunoassay.The purpose of this paper is:(1) Understanding the relationship between mating behavior and sex hormone level of the female Yunnan snub nosed monkey in different seasons;(2) Revealing the difference both in the aspects of mating behavior and hormone levels among the females under different physiological states. The main results showed as follows:1. In total, 345 times of successful mating behaviors were recorded during this study. The monthly average mating frequency was 29 times,ranging from 10 in December to 54 and 65 in August and September respectively.And among them, 113 times of mating ejaculation were also recorded, accounting for 32.75% of the total copulations. There were significantly higher in the ratio of mating ejaculation to copulations in the mating season,accounting for 81% than that in the non-mating season, accounting for 29.64%(χ2=49.603,df=1,p<0.01).2. Analysing the data of birth records from 2012 to 2015, we found that 28 infants was born from February to May, and 60.71% parturitions was found in March. It indicated that Rhinopithecus bieti had obvious seasonal birth peak.3. In the mating season, the estradiol(E2) levels of adult female was in continuous peak, and the fluctuation was not big, which was a sign of ovulation. After fertilization, the estradiol(E2) and progesterone(P) concentration of female were significantly increased, maintaining such a high concentration of persistent secretion, and the fluctuation range is bigger, that was a sign of pregnancy. A brief peaks both in estradiol(E2) and progesterone(P) concentration of adult female occurred in the birth season, then suddenly reduced, and maintaining in low concentration level, which was a sign of childbirth; During pregnancy, the estradiol(E2) and progesterone(P) of adult female suddenly reduced, which can be used as a reference of abortion. The estradiol(E2) and progesterone(P) of adult female was in the status of disorderly volatile with no regularity all year around, which was usually a sign of lactation.4. Although a peak of mating behavior of adult female individuals under different physiological status occured in the mating season, the ejaculation frequency of the lactating female was significantly lower than that of others.