Having written about birds preening yesterday, I walked around our garden early this morning looking for feathers that have dropped to the ground. This might occur as a result of a feather becoming worn or damaged so that it can no longer be smoothed into place. When this occurs, that feather will begin growing back immediately.

It is useful to know that feathers are made of keratin, as are our hair and fingernails. There are different parts to a feather and – although I couldn’t find a variety in our garden – different types of feathers, such as those shaped for the tail, wings, and breast of the birds, each fulfilling a different function. If we look at the complete feather below, we can see the main parts that make it up.

Basically, a feather is made up of a calamus (which could also be called a quill – hence quill pens), which is the hollow portion of the shaft that anchors the feather in the skin of the bird. The shaft (or rachis) is the solid, slender central part of the feather which tapers to a fine point at the tip of the feather. The vane is the plumed part of the feather that grows from this central shaft. Then there is the downy bit called the afterfeather. Here is a closer look.

You can clearly see the hollow portion of the shaft, the downy, lower barbs of the afterfeather, the solid rachis, and the vane – the plumed part of the feather that grows from the central shaft. What is really interesting about the structure of feathers – a lot to do with the preening process – is that the vane is made up of tiny structures called barbs. They are tightly packed together and each barb contains small ‘hooks’ called barbules that interlock with each other. Those lower, downy barbs lack barbicels because they are used for warm and are not needed for flight. The next time you find a feather lying on the ground, take a closer look at it. You might be surprised.

https://www.birdsoutsidemywindow.org/2010/07/02/anatomy-parts-of-a-feather/