 The calami of the flight feathers are protected by a layer of non-flight feathers called covert feathers or tectrices (singluar tectrix), at least one layer of them both above and beneath the flight feathers of the wings as well as above and below the rectrices of the tail. These feathers may vary widely in size — in fact, the upper tail tectrices of the male peafowl, rather than its rectrices, are what constitute its elaborate and colorful "train".
