【摘要】 198 1年重新发现朱后 ,至 2 0 0 0年的 2 0年中 ,朱的繁殖状况有了明显改善 .朱营巢地由 1981年的两处 ,增加到 36处 ,36处营巢地分属秦岭南坡中山区、秦岭南坡丘陵低山区、汉中盆地区和巴山低山丘陵区四种生态环境 .2 0年中 ,朱共计繁殖 12 1窝 ,产卵 36 4枚 ,窝卵数平均为 3 0 6枚 ,孵化率 75 5 4% ,繁殖成功率 85 95 % ,生产力 1 8.死亡雏鸟 6 0只 ,造成死亡的主要原因有疾病、天敌危害、人为因素和不良气候条件 .1981年只发现两对亲鸟繁殖 ,出飞幼鸟 3只 ,至 2 0 0 0年已有 19个繁殖对 ,累计出飞幼鸟 2 16只 ,种群数量增加了 30 9倍 ,其自然增长率γ =0 9119 (只 ·a) ,周限增长率λ=1 2 2 0 a.更多还原

【Abstract】 Since the discovering of Nipponia nippon in 1981, the environment for the reproduction of Nipponia nippon has improved alot during these 20 years.The number of the nest sites increased to 36 from 2 in 1981. They are located in the Southern part of the QinLing Mountain, in the hills of Southern part of QinLing Mountain, in Hanzhong Basin Area, and in the hills of Bashan Mountain. During the 20 years, Nipponia nippon reproduced 121 nests, with 364 eggs. Each nest averaged in 3 06 eggs, and the average hatching rate was 75 54 percent. The successful rate of reproduction was 85 95 percent. The production capacity was 1 8. Sixtybaby birds died of diseases, natural enemies, man_made factors and bad weather. In 1981, there were only two couples founded, whohatched three young birds. To the year of 2000, there were all to gether nineteen couples hatched, and 216 birds were given birth. The population size increased 30 9 times. The instantaneaus rate of increase was γ =0 911 9 bird per year; and the finite rate of incyease was λ =1 220 birds per yeas.更多还原