I've been looking for these things in the mobile revamp version. I found that if you don't find them near the obelisks, you should keep killing stuff there and leave the area, then return to keep killing until they spawn. There's also a good chance you'll find them in the redwood area; for instance, I found three of them flying above the redwood trees right in the center of the mountain. Another tip is to try eating rare flowers and then use a trap, or you can use the slow flyer grapple tactic to catch them.. Hope it helps people find them.