had the young out this morning they were just landing on loft when I heard a kerfuffle in the tree by loft out came my young one followed by the sparrow hawk thankfully youngster was ok and all safely back in now after flying round for ages and dropping on house roofs instead of loft as they usually do I lost its nest mate Sunday after hawk came flying round and scattered them
using black minerals yes, its mainly the young who have it, but yes it does look like when they are feeding air is good doors open all day and vents at bottom and a 2inch gap all round top theres 20 birds in a 6x 6 section