However, the biggest part of the contour feathers belongs to the body feathers (coverts) which are covering the body of the bird,
as you can assume from the name. You can also distinguish these in various groups of body feathers, which however only partly have own names.
The coverts are arranged imbricate one upon the other and protect against moisture and wind quite well. Every vane of a feather has got side
branches of first and second order, the ramus and the radius of a feather. At the lower part of the feather quill the side branches are arranged
loosely; they form the down part, generally
called sub-plumage. Like the downs this feather part is responsible for warmth protection. More above the feather radius are hooked
together and so they form a more or less closed surface. The basis of the tail feathers is covered
by the upper and the under tail coverts, respectively, on the top side as well as on the underside. The body feathers can be
symmetrical as well as asymmetrical, rounded or pointed and huge or small.
Downs: Like the down part of the coverts they are completely fit out with a loose, fluffy cave. The side
branches are practically not hooked together. The downs (also called downy feathers or plumules) form the sub-plumage. They have a soft
shaft and only serve for the regulation of warmth. Usually, these feathers are grey at the Lineolated Parakeet,
however, at the "Inos" they are white.
Powder downs: Apart from the parrots, you can find these feathers at e. g. doves and herons as well. They produce a fine-grained, wax-like
skin powder which serves for plumage care and supports the
function of the plumage as e.g. protection against water.
Hair feathers (or filamentous plumes): Actually, they only consist of a more or less long shaft. There can be a little feather cave at
the end. Hair feathers can be found separately or in groups in the direct neighbourhood of the coverts. Their follicles are placed
in an area rich of nerves, so that the hair feathers are able to correct the position of the body feathers in case of
Bristle feathers: They mainly can be found in the nose region and as "eyelashes". The bristle feathers show a short,
stiff shaft, with or without a thin feather cave. Possibly they fulfil a function like the tactile hairs of the mammals.