Neck feathers are a type of plumage found on many birds, and two common examples are the BOA and the RUFF. The BOA is a type of feathery collar found on some species of birds, such as the peacock, and is usually composed of long, thin feathers. The RUFF is a type of neck feather found on some species of birds, such as the grouse, and is usually composed of short, thick feathers. Both the BOA and the RUFF are used by birds to attract mates, as well as to provide insulation and protection from the elements.