The Orcish Trackers (Or."Gayirmi") or Snufflers (Or."Smakurr") were a special breed of lesser Orcs.They were small, swarthy and squat with wide nostrils and had a superior sense of smell.They were skilled Hunters, Archers, Scouts and Spies.
In LOTRRPG the orcish trackers are equated with the wood- or forest breed orcs.
In the LOTRSBG orc Trackers are a special Unit of Mordor.
Some fan-fiction stories set in Middle-Earth give the orcish Trackers the name Gimba-Hai ("Finder-People").