I'm not really sure where the birds were but I flew through this stage for quite a while and gave up. Has an endless world feel which was fun at first but then just got tedious to me. Maybe some sort of visual or audial cues to where to search? Birds chirping in the distance or something similar.
Making the birds stand out was a huge challenge and I'm definitely aware that it's not ideal. However our main focus was the visual aesthetic.
For cues, there is a white highlight around the birds and they do play an instrument that comes into hearing when you get near them; but I know that those are likely too subtle for someone new to the game.
Thanks for the feedback!