This game is so well designed, I can't imagine something in it that serves no integral purpose. So what about the birds?
Is there a way to catch them, either for food or pets? (When food was scarce, I kept imagining they were like the quail in the wilderness after the Israelites fled Egypt.) Do the birds serve any role other than beauty? I paused the game while they were in flight - quite impressive!
Also, I thought the Feather Collectibles would be more prevalent after the birds leave, but it doesn't seem to be the case. Hmmmm ...
(Thanks, LDW, for the Search engine - it showed no one had mentioned avians yet. So I think I'm safe starting this new topic.)