EZ way to find them on Lost Island. Fly to the green obelisk then sight a little round island on desert shore, fly straight for that island then sight large black jutting rock formations. They can be found near those formations and along the desert boundary on the right and behind the jutts. I took a wyvern and built a low level trap, picked up a 140 and a 130 yday. Bring cryopods for easy transport..