Characteristics of the four networks (Backbone, Frequent, Intermediate, Occasional) and the Overall one in the two periods of the year (January-August, September-December).

Characteristics are summarized by species involved, means of transportation, national or not and reason of the movement (types of activity at origin and destination). Volume is expressed in million heads. Percentage referred to the volume specific of the period.

本数据集的特征按涉及物种、运输方式、是否跨境以及移动动因（起运地与目的地的活动类型）进行汇总。总量以百万头为单位计量。相关百分比均以对应时段的特定总量为基准计算。