During two consecutive mating seasons from August 2001 to December 2002,we observed the sexual behavior of Sichuan golden monkeys in the Chengdu Zoo and the Shanghai Wild Animal Park. We collected urine samples from females in the early morning. We also measured urinary estradiol and progesterone levels using radioimmunoassay. Based on the estradiol concentration during the menstrual cycle, we discovered that the length of the menstrual cycle was 286 33±1 67 days. The length of pregnancy was about 200 days. The level of estradiol after impregnation was significantly different with the level during the same period in the non receptive part of the cycle. Thus we could diagnose early pregnancy in female Sichuan golden monkeys by checking their urinary estradiol level .
In order to reveal the biochemical basis for the pharmacological use of the antler velvet of Père David’s deer (Eluphurus davidianus), we analyzed the estradiol concentrations of velvet tissue samples. We collected velvet tissue from Père David’s deer, sika deer (Cervus nippon) and fallow deer (Dama dama). After extracting steroids from velvet tissue with ether, we analyzed the estrdiol concentrations using radioimmunoassay technique. We found that: (1) estradiol concentrations were significantly different in the velvet tissue of these three cervids (P<0.05) and (2) Père David’s deer stags had the highest velvet tissue estradiol concentrations, 105.29±27.53 pg/g. [Acta Zoologica Sinica 49(1):124-127,2003].
In 1999, we observed six Père David’s deer calves (3 male and 3 female), which were born in the Beijing Milu Park to study the synchronization of action and grouping behavior in those calves. The observation began in the second week of their births until their weaning, altogether, we collected 4 320 behavioral records. We established two indexes, the Index of Activity Synchrony, A, and Daily Frequency of Calves in the Same Cohort, P, for measuring aggregate behaviour in calves. Before their weaning, the calves synchronised their activity (A=0.87±0.006), and they stayed in same cohort most of the time (P=0.86±0.012). No sexual segregation behaviour was found in the calves. There were no significant differences of A (F=0.075, P=0.788, df=1) and P (F=0.489, P=0.497, df=1) in the calves of the same sex or between opposite sex. However, Index A and P changed significantly as the ages of the calves increased. Daily frequency of calves stayed in the same cohort could not present aggregation tendency of calves exactly. At 4 week old, calves expressed the highest activity synchronization.
