Vitapet: Bird Grit 350g
Birds are not too particular and will ingest some items that are easy to digest and some items that are not.
The purpose of grit is thought to help the bird grind up difficult to digest items.
By grinding, it is thought that these food items become better utilized by the bird.
Since the primary purpose of grit is to help remove husks and shells from seeds, birds that ingest whole seeds, like doves, would likely be the best candidates for needing grit in their diets.