Finding someone with a flying crane is a secret technique of the Taiyi Sect. One infuses a crane with a person's aura using magic, and after supplying it with spiritual energy, the crane tracks down the owner of that aura.
There is a limitation, however: it does not work beyond ten kilometers.
The fact that the crane was still flying meant that Shu Wangyue and the others were within a ten-kilometer radius.
Chapter 26