摘要
研究青藏高原胡兀鹫的繁殖成功率、种群现状、种群变化趋势和致危因素,为制定和实施合理有效的保护措施提供参考。[方法]主要调查时间为2010—2013年以及1991—1993年。调查区域包括西藏的昌都、林芝、那曲和拉萨地区,四川的甘孜和阿坝自治州,青海的海北、海西、果洛和玉树自治州以及甘肃的甘南自治州。在这些区域中的7个胡兀鹫繁殖地,对某些繁殖巢进行日活动行为观察,以确定其繁殖参数。繁殖成功率依据2010年冬季至2013年秋季观察的繁殖巢中离巢出飞的幼鸟数量确定。由于缺乏对大范围面积（超过1万km2）内准确繁殖对数目的调查数据,仅能以繁殖对之间的繁殖巢间距来换算其领域面积。种群结构大多情况下采用路线统计法（截线法）调查记录,少数情况下在动物尸体附近进行观察。将胡兀鹫划归为3～4个年龄组：幼体（〈3年龄）,未成熟体（3～4年龄）,亚成体（4～6年龄）和成体（〉6年龄）。针对胡兀鹫种群结构的观察记录工作分别在1992年的4月—1993年2月下旬（合计48天）和2010年12月初—2012年10月下旬（合计103天）进行。繁殖种群数量评估,参照文献报道的高山兀鹫种群数量,以同期（2010年冬季至2012年底）调查的胡兀鹫繁殖巢数量与高山兀鹫繁殖巢的数量进行对比,其比值乘以高山兀鹫种群数量,以此估算胡兀鹫的繁殖对数量。[结果]胡兀鹫产卵期为12月上旬—1月末（12月7日—1月28日,n=4）,孵化期为55～61天（n=3）,窝卵数平均为1.86枚（n=14）,测量3枚卵的平均长和宽为84.4（83.1～88.3）mm和68.03（67.0～70.0）mm。繁殖成功率为81.82%（2010年—2012年,n=22）。巢址分布海拔为2 600～4 575 m。在具有代表性的繁殖地内,繁殖对之间距离平均为35.84 km（25.10～47.3 km）,领域平均面积为1 284.51 km2（630.01～2 237.29 km2）。20年来（1990年以来）种群结构变动为：胡兀鹫幼体数量比例从30.17%（n=116）降低到16.67%（n=96）。估算青藏高原250万km2面积的胡兀鹫种群数量不超过1 410个繁殖对。[结论]初步确定胡兀鹫的致危因素超过10个。人类社会的现代化进程、各种基础工程设施的建立,尤其是边远荒僻区域居民生活方式的改变是影响胡兀鹫繁殖成功率和种群稳定性的重要因素。
[Objective]Bearded Vulture （ Gypaetus barbatus ） is listed as one of the first-grade national protected wildlife species in China,which means the population of Bearded Vulture is at the margin of extinction. Nevertheless, very little information has been published on the basic aspects,such as the reproductive ecology,population status and endangerment mechanism. For the sake of protection of this endangered species,it is necessary that systematic researches should be carried out on its reproductive ecology, the human disturbance impact on its population dynamics, the mechanism of endangerment,the negative factors from human and nature and its own defects of behaviors responding to the changes of environment. The objective of this study is to curb the tendency of endangerment of Bearded Vulture and other endangered species,and find the strategy to save the species from extinction in the wild.[Method]Study area：The survey was carried out in the Qinghai-Tibetan Plateau from 1991 to 1992 and from 2010 to 2013 . The survey covers the work area includes the following：1） Changdu,Linzhi,Nagqu,Lhasa area of Tibet Tibetan Autonomous Region; 2） Ganzi,Aba Autonomous Prefecture of Sichuan Province; 3 ） Haibei,Haixi,Guoluo （ Golok ） and Yushu Autonomous Prefecture of Qinghai Province;4）Gannan Autonomous Prefecture of Gansu Province. In these areas,there are 7 breeding places of the Bearded Vulture to be found. Data collection：Observations of daily activity behavior were performed for some nests,in order to determine the reproductive parameters. The breeding success rate is based upon the number of young fledg/number of breeding pairs in the winter of 2010 to the autumn of 2013 . The data were not included in the uncertainty whether the young birds flew out of the nest. In view of the lack of investigation data with regard to the exact number of breeding pairs in a large enough area （ 〉10 000 km2 ） ,therefore,the territory area can be converted only by the distance between the nests of 2 -3 pairs in the suitable breeding habitat. As for population structure,survey data were collected by using transect investigations which mainly was conducted with motor vehicle,sometimes on horseback or on foot,and random observation samples （ mostly from vantage points with good views over the sampling areas, also including observation on the carcasses） . These investigations were conducted for 48 days from 1992 April to 1993 late February and 103 days from 2010 early December to 2012 late October,respectively. Each Bearded Vulture sighted was classified to one of four age classes： juvenile （ 〈3 years）,immature （3 -4 years）,sub-adult （4 -6 years） and adult （ 〉6 years）. According to the total population size of the Himalayan Griffon Gyps himalayensis that has been reported,the Bearded Vulture breeding nests were compared with breeding nests of the Himalayan Griffon at the same period （ from the end of 2010 to the end of 2012） to estimate the total breeding population size of this species.[Result]The results indicated that laying date of the Bearded Vulture began in early December and lasted until late January （ range from 7 December to 28 January,n = 4）,and incubation period was 55 to 61 days （n = 3）. Mean clutch size was 1. 86,and 85. 71% of nests contained two eggs （n = 14）. The mean size of 3 eggs measured was 84. 4 （83. 1 -88. 3） mm in length and 68. 03 （67. 0 -70. 0） mm in width. Breeding success rate was 81. 82% （2010 -2012,n = 22）. The altitude range of nest sites was from 2 600 m to 4 575 m. The average distance between the breeding pairs was 35. 84 km （25. 10 -47. 3 km）,and territorial area was 1 284. 51 km2（630. 01 -2 237. 29 km2）. The proportion of juveniles was reduced from 30. 17% （n= 116） to 16. 67% （n = 96） during the past 20 years,and the reduction rate was 44. 75%. The proportion of adults was increased from 61 . 21% to 70 . 83% （ since 1990 ） . Those results suggested that the reproductive success rate and population quality decreased obviously. According to the published literature data for the evaluation and analysis,we＆amp;nbsp;believe that the total population size of the Himalayan Griffon in the Qinghai-Tibet Plateau would be about 100 000 , therefore,the number of breeding pairs should be less than 50 000 （ if considering the non-breeding birds,the value would be reduced by at least 30%）. When the research project was implemented during the 2012 to 2013,a total of 11 Bearded Vulture’s breeding nests and more than 390 Himalayan Griffon’s breeding nests were found. According to the proportion calculation,we estimated the population size of the Bearded Vulture was less than 1 410 breeding pairs in the plateau region （ about 2. 5 ＆#215; 106 km2 ） .[Conclusion]It can be preliminarily determined that there would be more than 10 threaten factors to the Bearded Vulture. The modernization process of human society life,the establishment of various infrastructure projects,especially,people＆#39;s lifestyles change in the remote mountainous area,would be important factors to affect the breeding success and population stability of the Bearded Vulture.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2015年第9期78-89,共12页
Scientia Silvae Sinicae
基金
国家自然科学基金项目(31071933)
国家科技基础条件平台"自然保护区生物标本资源共享子平台"(2005DKA21404)
关键词
胡兀鹫
青藏高原
领域面积
种群密度
种群结构变化
Tibetan Plateau
territorial area
population density
variation in population structure
