Pennaceous feather

The contour feathers (Latin Pennae conturae ) are a type of spring. The contour feathers form the predominant part of the externally visible plumage. The whole of the contour feathers that serve the body covering is referred to here as small feathers, the flight feathers of the wing and tail feathers of the tail as big plumage.

Classification

The contour feathers are functionally and according to their location further divided into:

• Body feathers ( Pennae conturae generales ): coverts of the hull
• Flight feathers ( remiges ): form the actual bearing surface of the wing at hand ( swing ) and forearm ( secondaries )
• Tail feathers ( rectrices ): tail feathers. They are numbered from the inside to the outside. The mean is therefore S1, the outermost S6, when six springs are present on each side.
• Coverts ( Tectrices ): other feathers on wings and tail

Construction

The contour feathers consist of a long and solid quill ( scape ) and a feather banner ( vexillum ).

The quill is further divided into the feather shaft ( rachis ) and the spring coil ( Calamus ). At the coil, there are two openings: an upper navel (umbilicus superior) and a lower navel (umbilicus inferior). The coverts are found in many species above the upper navel an extension spring ( Hypopenna ).

The spring tab is divided into an outer flag ( vexillum externum ) and indoor banner ( vexillum internum ). The outer webs covering part of the adjacent spring, while the internal flag is covered by the adjacent spring. Both flags are made from the feather shaft outgoing front and rear spring branches ( barbae or Rami ), of which each again arc rays ( Barbulae proximal ) and hook rays ( Barbulae distal ) arise. Sit fine hooks that stick to the arc rays of neighboring Federastes and thus make the necessary rigidity and strength of the spring tab on the hook rays.