Pecking and chomping is pretty much their job description!
Unicum arbustum haud alit duos erithacos
(One bush does not shelter two Robins)
Zenodotus (3rd Century B.C.)
Not forgetting that Goldfinches tend to reject about 5 out of 6 Sunflower hearts before eating one, and then a little forest of sunflower plants feebly begins to grow under the feeders in the grass!
Kind regards, Ann