How does the tracking window work?

[Ooloo]

I've always wondered about the specifics of the tracking skill and how it works.

What determines the order of mobs listed in the tracking window? Their relative proximity to you, or how long they've been alive? Or neither? Or both?

Why do mobs disappear in real time from the tracking window when killed, but it doesn't update with new mobs that spawn or new mobs that you've come into the proximity of without having to wait and actually use the skill again to refresh it?

Other than skill = diameter of trackable area, it's still a big mystery to me.

Yes I'm trying to kill quillmane.