When you think of something that all birds have in common, what is one thing you think of? Maybe you said that birds have beaks and lay eggs, but so do some other animals like turtles. Maybe you said that most birds fly, but so do bats and insects. What is something that is unique only to birds? Feathers!
So what exactly are feathers? While there are many different types of feathers they are all made of the same material, keratin. Keratin is a protein and it is the main building block of many things that we are familiar with. Hair, nails, and horns are all made of this protein. In birds, keratin is the building block of talons, beaks, and of course feathers. Depending on where a bird’s body the feathers are located, they can serve many different functions. Flight, thermoregulation, camouflage, communication, and more. The basic structure of a feather includes a rachis, which is the thick central shaft of the feather. Barbs come off of that central rachis and hook together by microscopic barbules, almost like Velcro! These intricately connected barbs form vanes. Some feathers, like flight feathers, have highly structured barbs while others like downy feathers are much looser and less structured.
Wing and tail feathers:
The barbs on wing and tail feathers are tightly connected to form a smooth vane on either side of the rachis. In wing feathers, this creates an aerodynamic surface that can create lift, the upward force that keeps a bird in the air, during flight. Wing feathers are also crucial to creating thrust. Thrust is the force that moves a bird forward in the air. Wing feathers are unique in that they usually have a wider side and a narrower side on either side of the rachis. This again helps their wings to be aerodynamic and helps to reduce drag.
Tail feathers are also highly structured. They are movable and can be separated and rotated. This is helpful in steering and landing. They are different from flight feathers in that they are balanced on the left and right side of the rachis.
Semiplume: Semiplume feathers have a looser structure than those of the wing and tail. These are feathers that are close to the bird’s body and are involved in insulation and often courtship displays
Down feathers: Down Feathers are very short and lack the micro-barbules that keep the shape in wing and tail feathers. That is why they look so fluffy and “messy”. They provide great insulation!
Across the globe, you can find birds with extraordinary feathers in every color and shape imaginable. While they may look very different, it is fun to remember that they are all made of the same building blocks, have the same basic structure, and are a characteristic that all birds have in common.