I think I saw a nest with eggs on the west side of North Island (area between Wlling and Kelan Village) but the nest is in the terrain that can't be traveled by foot (I didn't see any path to the nest besides flying). It looks like the nest where the egg was stolen from and it is unoccupied. Sorry, I'm not far enough in the game to get to the nest and find out. The nest can be seen north-west from 1762, 1595 so I hope somebody that could fly to the nest will see if it is where you get the egg.