https://www.ign.com/wikis/yokus-island-express/Wickerling_Lo...I found 3/4 trackers just by playing the game. These were Crystal deep, Ivory Peaks, Marrow hills. I believe you buy crystal deep and marrow hills. You find Ivory peaks in a chest that you must use a slug for.
The 4th one for Gorilla woods is found on the right side of the waterfall. There is a rabbit you must talk to, then press
a bunch of times to get rid of the sootlings and go back to the rabbit. It is free so don't worry about needing fruit.