Abstract: In an ideal world, estimation of wildlife populations would always use rigorous methods and statistically valid sampling. Unfortunately, field conditions sometimes make violating important model assumptions unavoidable or obtaining random samples impossible. In such cases, proceeding as though these difficulties did not exist and reporting unreliable results as though they arose from rigorous procedures can be worse than having no data at all. For some management objectives however, it is not necessary to obtain accurate enumerations of an entire population; rather, the long-term population trend is sufficient to guide managers. In China, objective and quantitative long-term monitoring of large mammal species has not often been conducted. Here, we provide an overview of 2 long-term trend monitoring programs focusing on wild ungulates of the Tibetan plateau in Qinghai and Gansu provinces. We stress the importance of maintaining consistency in methods among years, and in understanding that numerical results contain uncertainty. Despite this uncertainty, large changes in abundance are very likely to be detected using such trend monitoring, and can help managers respond appropriately.

Key words: Aksai County, Argali(Ovis ammon), Chiru (Pantholops hodgsoni), Gansu, Qinghai, Trend monitoring, Wild yak( Bos grunniens), Wild Yak Valley

摘要： 大型野生动物种群数量估算的理想条件是使用数学模型以及严格的实验设计来选择样本。可是，野外条件状况往往违背数学模型假设前提，不可能随机地选择样本。于是，计算的结果不但不可靠，而且很可能没有意义。就野生动物管理来说，不需要获得一个准确的种群数量，只需一个长期的数量趋势，就可以指导相关管理工作。在中国大型哺乳动物长期监测还没有纳入常规。本文报道了位于青海野牛沟和甘肃阿克塞县两个野生有蹄类动物种群数量的长期趋势监测项目。我们这些年里一直用相同的方法持续监测，并明确了监测数值结果包含有不确定性。尽管存在不确定性，仍可以发现监测地点野生有蹄类动物种群变化趋势，这些结果可以帮助野生动物管理者据此变化及时作出相应管理计划。

关键词: 青海野牛沟, 甘肃阿克塞县, 盘羊, 野牦牛, 藏羚羊, 狩猎, 趋势监测