Birds did not rise from the dinosaurs' ashes: they lived alongside the dinosaurs for a hundred million years before the extinction.

Palaeontologist and reader in zoology at Queen Mary University of London

So birds did not appear as a result of the dinosaurs going extinct. Birds lived alongside the dinosaurs for 100 million years. The birds were not new on the scene, and it's not like, "Oh, the dinosaurs died, and from the ashes rose the birds." No, they've been knocking around forever.