关键词: Andrias davidianus, 人工放流, 资源增殖, 野生种群, 生境

Abstract

Chinese giant salamander (Andrias davidianus) is a native amphibian to China. It was listed as a Class II protected wildlife species under the state conservation law largely due to its sharply declined population size in the past two decades. Habitat destruction, habitat degradation and human over-exploitation have been considered as the primary causes of the declination. Designed to boost the wild population, a captive breeding program has been successfully established and artificially bred individuals have been released into the wild for many times in the Hunan Zhangjiajie Giant Salamander National Nature Reserve between 2002 and 2008. In 2007 and 2008, we examined these released salamanders to evaluate the effectiveness of the release. We also investigated covert, water quality and food organisms of the releasing sites to explore factors that may determine the success of release. A total of 995 different sized salamanders were identified as 11 cohorts at nine releasing sites. However, only four cohorts were identified as successful in terms of wild population size increase. In all successful sites, released salamanders were mature, weighing 1-4.5 kg, and sex ratios were between 1:1 and 1:1.5. Moreover, some protection measures were taken including food supplementation in these sites. Most releasing sites appeared to satisfy the demands for growth and reproduction of the salamander, however, most releases failed to boost the wild populations likely due to the limitation of the factors such as water quality, food organisms and safety. In conclusion, habitat traits of releasing sites and subsequent management measures, as well as individual size of salamanders were the major factors affecting the releasing effectiveness. In view of the habit of the salamanders, it is better to select mature salamanders for release in spring.

Key words: Chinese giant salamander (Andrias davidianus), releasing into the wild, stock enhancement, population, habitat