What Are Pinfeathers on Birds?

smaller. These barbs and barbules have small hooks that allow the bird to zip her feathers and preen them to make her feathers lay very orderly and neatly on her body. This grooming is necessary for the feathers to function properly while flying as well as trapping air between the feathers and her body keeping her warm. This zipping hooks up the feathers using the barbules as fasteners. When a bird is properly groomed with all of her feathers zipped it forms protection from wind and moisture. 
Contour Feathers
Contour feathers are the majority of what you see on the bird. The contour feathers follow the shape of the bird quite closely making the bird quite streamlined. A good example of this can be seen on the penguin where the feathers are so close together and tight on the body that it actually looks like skin rather than the feathers that are actually 

present.
Arranged in an overlapping pattern very similar to scales on a fish or a reptile the tips of the feathers are exposed and can be seen while the fluffy bottoms of the feathers further down the shaft of the feather to the base are folded in close to the body. You will find that females are a more drab or plain color than the male of the same species in many cases. This makes it easier for the female to stay camouflaged while she is sitting on her eggs or protecting her babies. 

Pinfeathers During Preening
While birds remove most of their pinfeathers during preening there are always a few most notably on the top of the head that they cant quite reach. In the wild other members of the flock would help with the pinfeathers during natural grooming behaviorsbut in captivity you can assist with this preening by
removing the shafts from the pinfeathers. You can do this by gently rolling them between a thumb and forefinger.