Oddly enough, the anthropological literature is fairly silent on the specifics of tracking; I really can't think of any decent references, although surely some must exist somewhere.

I am afraid I can only recommend Tracking: A Blueprint for Learning How, by Jack Kearney. "La Migra" (Border Patrol) is probably not what you had in mind when you specified indigenous groups, but I'll bet the basic skills are cultural universals and require intimate knowledge of the local environment in order to detect disturbance.

In few other pursuits does Yogi Berra's famous dictum, "You can observe a lot just by looking" apply more aptly than to tracking. Another cliche - practice makes perfect.