Only the 180 birds from base game and swift-start pack were considered.
Check out Flan's channel, Wingin' It:
https://www.youtube.com/channel/UC1gZvCZ3qUyRKdBeB1jChyQ
Thumbnail image credit:
Andrew Weitzel from Lancaster, PA, USA, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons