内蒙古贺兰山冬春季岩羊种群现状及保护

为调查内蒙古贺兰山国家级自然保护区内岩羊（Pseudois nayaur alashanicus）的种群现状，通过样线法在2017、2018年冬季，2018、2019年春季进行了调查，利用R 4.0.3中的Distance 1.0.2对样线观测数据进行分析，估测保护区内岩羊的种群数量及密度，分析其种群结构。结果显示，调查共观测到岩羊6299只，其中，2018年冬季种群数量最高，约为2654（2230-3161）只（括号内为95%数量置信区间），种群密度为3.921（3.293-4.668）只/km²。与2003年同季节的调查数据对比发现，保护区内岩羊的种群数量在15年间增长迅速，岩羊的种群密度累计增长了约53.17%，年平均增长3.54%。岩羊集群形式：混合群（88.03%，80.95%）为岩羊冬、春最主要的集群形式，且混合群的数量冬季多于春季，独羊出现的次数最低（1.99%，2.86%），不同的集群类型在不同的季节的差异极显著（P<0.001）；岩羊平均群大小：春季为（13.439±12.085）只，冬季为（9.011±8.610）只，调查季节中集群大小多为1-10只，岩羊的不同季节的群大小差异极显著（P<0.001）。种群成体与幼体比在不同季节的变化范围为1.411-2.673，雌雄比在不同季节的变化范围为0.934-1.469，种群结构的季节性差异极显著（P<0.001）。集群类型、群大小及群组成的调查表明，不同季节间岩羊种群结构差异明显。

Population status and protection of Blue Sheep in Helan Mountains of the Inner Mongolia, China

In order to investigate the current population status of blue sheep (Pseudois nayaur alashanicus) in Helan Mountain National Nature Reserve of Inner Mongolia, field work was conducted in the winter of 2017 and 2018 and spring of 2018 and 2019 by using the line transect method. Distance sampling (v1.0.2; R 4.0.3) was used to analyze the observed data to estimate the population size, density and structure of blue sheep in study area. Our results showed that a total of 6299 were observed, of which the highest population size was about 2654 (2230-3161) (The 95% quantity confidence intervals are in parentheses) in the winter of 2018, and the population density was 3.921/km²(3.293-4.668/km²). Compared with the monitoring data of the same season in 2003, it is found that its population has increased rapidly in the past 15 years, and the population density has increased by approximately 53.17%, with an annual average increase of 3.54% in study area. Meanwhile, different group types of blue sheep were monitored and showed significant differences in variant seasons (P<0.001). The mixed group was the main group form of winter (88.03%) and spring (80.95%), and its number in winter was more than that in spring, and the lowest frequency of occurrence was single individual, which lives alone both in winter (1.99%) and in spring (2.86%). There was a significant difference in the population size between winter (13.439±12.085) and spring (9.011±8.610) (P<0.001), and the population size of blue sheep was mostly 1-10 in survey season. The ratio of adult/juvenile and female/male varied from 1.411 to 2.673 and 0.934 to 1.469 in different seasons respectively, which indicated a significant seasonal difference in population composition and structure (P<0.001). Based on the results obtained in current study, we demonstrate that the population structure of blue sheep varies significantly among different seasons. In common sense, climate and resources are important drivers of species development, therefore the further study should focus on the factor of phenology and resources.