湖北石首麋鹿国家级自然保护区麋鹿种群动态

Population dynamics of the Père David’s deer Elaphurus davidianus in Shishou Milu National Nature Reserve, Hubei Province, China

为实现麋鹿回归大自然的目标,1993年和1994年,湖北石首麋鹿国家级自然保护区(以下简称石首麋鹿保护区)分别从北京麋鹿苑引入麋鹿30头(8♂,22♀)和34头(10♂,24♀)建立了繁殖种群。自2000年6月开始,作者每月一次(7-10d)实地监测石首麋鹿保护区内、外的麋鹿种群动态。到2006年产仔季节结束后,该保护区内的麋鹿种群达522头,2006年产仔前性比为1∶1.22。用指数增长模型拟合种群增长曲线,1998年后石首麋鹿保护区内的麋鹿种群呈指数增长(Nt=84e0.226t),其瞬时增长率为0.226;1998年夏季长江暴发特大洪灾,石首麋鹿保护区内的部分麋鹿逃逸到长江南岸,形成了自然野化麋鹿种群。该自然野化种群比保护区内麋鹿种群增长快,其瞬时增长率达到0.267。湖北石首和江苏大丰两个国家级自然保护区内麋鹿种群的出生率和增长率差异显著,而两地的死亡率无显著差异。石首麋鹿保护区内的麋鹿种群年均出生率(26.8%,P=0.010)和年均增长率(21.7%,P=0.038)均显著地高于江苏大丰国家级自然保护区内麋鹿种群的年均出生率(21.6%)和年均增长率(17.0%)。由于生境退化和人为干扰,当前石首麋鹿保护区内的麋鹿种群增长已开始出现密度制约迹象,亟待采取有效措施来改善麋鹿的生存繁衍条件。

In order to establish a wild population, Hubei Shishou Milu Natinal Nature Reserve introduced 30 （8♂ , 22♀ ） and 34 （10 ♂, 24-9♀ ） Milu （Pere David＇s deer） from the Beijing Milu Park to establish a breeding herd in 1993 and 1994,respectively. Since June 2000, we have monitored the population trends of reintroduced Pere David＇ s deer in Shishou Milu National Nature Reserve. Until the end of the calving season of 2006, there were 522 P^re David＇ s deer in the reserve. The growth of Milu population fits the equation： Nt= 84e^0.226t . The sex ratio in the Milu population was 1 ： 1.22 （ ♂ ： ♀ ） before the calving season of 2006. Owing to heavy floods in the Yangtze River during the summer of 1998, some Milu escaped from the fenced area in the reserve to the south of the Yangtze River. According to the fitted population growth model, the population growth rate of Milu inside the reserve was 0.226 which was lower than that （0.267） of the Milu that live outside the reserve. The mean annual population growth rate of the Milu that live outside the reserve was also higher than the population inside the fenced reserve. Compared with those of the Dafeng Milu National Nature Reserve, the mean annual birth rate （26.8%, P = 0.010） and the mean annual population growth rate （21.7 % , P = 0. 038） of the Milu population in Shishou Milu National Nature Reserve were significantly higher than that of the Dafeng population. However, there was no significant difference between the mean annual mortality rates between the Shishou and Dafeng populations. Due to habitat deterioration and human interference in the Shishou nature reserve, some conservative measures should be taken urgently to improve the living conditions of Milu because the growth of the population has started to show a density-dependent pattern [ Acta Zoologica Sinica 53 （6）： 947- 952, 2007].