That's how I got my lvl 56 4* bird. But, I've retried this method multiple times with no success. I've tried following the gems, essences, etc to no avail. The highest I've been able to get to since, is level 20 or so. I wish instead of doubling gems each time a pig was encountered, that it cost 50 or even 100 gems each time. That way unlucky players have a better chance it getting a high level bird. ANGRY BIRDS EVOLUTION - EAGLE MOUNTAIN (BLACK) to LEVEL 60 - GET 4 STARS BIRD MORE ANGRY BIRDS EVOLUTION https://www.youtube.com/playlist?list . Signed in this morning to find there was an additional feature called "eagle mountain" where > Angry Birds Forums > Angry Birds Evolution in Eagle Moutain .