Birds have feathers for different reasons. It gives them good insulation against cold conditions and a waterproofing ability against rain. In the breeding season, it gives a colourful and attractive look to impress each other, more specifically, the females. Do not forget the very importance of camouflage as a part of their survival. This very light and strong aerofoils (feathers), make it possible for sustained flight in the most efficient way.
Feathers demand respect for its strength when you realize:
- A bat’s webbing is not as strong or light.
- The wings of insects are much more vulnerable and not as resistant to damage as those of birds.
This light aerofoils have different functions and can be divided into five basic types. The most visible feathers that provide streamlining, protection and shape are called the contour feathers. Like humans, the body of the bird needs to operate at the most ideal temperature. The feathers that provide warmth and insulate the body are called down-feathers. Young birds are covered with these feathers.
With adult birds between the contour and the down feathers, there are gaps that need to be filled. The feathers filling those gaps are called semiplume feathers.
The visible organs of birds get protection from the bristle feathers. These bristle feathers act as eyelashes for the eyes, cover the nose and sit around the beak. It is important to keep these feathers in tip-top condition. This action is called preening. The feathers that act as sensors and which will tell the bird when some of the feathers are out of place is called filoplumes and is scattered throughout the body.
The light aerofoils or feathers are made out of dead protein material called keratin. This keratin is tucked away within a follicle in the skin of the bird. From the follicle, it will grow to a strength greater than the hair, horns or hoves of mammals. Feathers grow in lines called tracks. When a feather is shed a new growth starts from the same follicle.
Birds use their bills or claws to zip up ruffled feathers. This is made possible by a part of the feather called barbicels and not all feathers pose this part.
We will talk more about birds in later blogs:
What do you think……?
- Why do birds fly in formation?
- How high can birds fly?
Author: Reinier Bredenkamp