野生大熊猫生命表初编

A STUDY ON THE LIFE TABLE OF WILD GIANT PANDAS

本文用门齿齿质生长线数目共鉴定69号大熊猫标本的实际年龄,结合野外观察资料编制出大熊猫的生命表、内禀增长率及繁殖价表。并对大熊猫犬齿的直径和高度进行统计分析,确定了用犬齿大小辨别大熊猫性别的方法。

During 1984-1986, we have got 69 specimens died in the field and determined the age of each specimen by cementum layers of incisors. According to the specimens we have studied the life table.The results are as follows: Through the x2-test the sex ratio of pandas is 1:1. After calculating forth-back, left-right width and height of the upper and lower canine and through variance anal-ysis we find the male panda's canines are much bigger than those of the female pan-das.We can judge the sex by the canines. The youngest reproductive age of male panda is 7.5-8.5 -year-old and the female panda's6.5-7.5.The oldest leproductive age of the male perhaps is 21 and the female can not be exactly known.But at least a 13-year-old female can breed. According to the 61 specimens and observed directly the cubs,death rate we have made the life table,survival curve,death curve and death rate curve.The survival cu-rve is like the letter 'L' which indicates the high death rate of cubs.The death curve shows two death peaks:cubs and 12-14-year-old. The net reproductive rate R0 =1.0672,the intrinsic rate of natural increase r =0.0056 the mean time per generation T = 11.6790. The 6-8 year-old pandas have the greatest reproductive value.As the age increa-ses the reproductive value increases before 6-8 and decreases after 6-8. As the bamboo has died of blooming in large area in recent decade and the food shortages during the past,the population are constantly declining.According to Ro>l we know that the population may slowly increase as long as we protect the habits and renew the food bases.The herd of 'WUYIPENG' has verified this point.