The group and activity law of large-billed crows (Corvus macrorhynchus) have been studied in the alpine area during spring of 2004. 35 representative zones were sampled as line transects, which are between 30 and 50 km in length.

• 在2004年春季,对高寒地区大嘴乌鸦(Corvus macrorhynchus)的集群与活动规律进行了调查研究,共设置了35个有代表性的样线。