Feathers have a long lineage. Quite a few dinosaurs sported these colorful bits of keratin. Now they are the hallmark of birds. If a creature has feathers, it is a bird.
All feathers have a central shaft. This is the backbone on which the feather is built. It is stiff and hollow with a big pointed end that anchors the feather in the bird and a thin end at the other end.
Wing feathers have stiff branches lined thickly along the length of he shaft. These make the feather broad to catch the wind. Yet, stiff as they are, these branches would break if they had to work alone. Strength comes in forming a wall.
A brick wall uses mortar to glue the bricks together. Feathers use tiny hooked barbs. If you take a wing feather and pull some of these branches apart, you can feel the barbs pulling apart.
Wind can pull the barbs apart. This is one of the reasons birds preen. They are using their beaks to hook the barbs back together. You can do the same by pulling the open section through your fingers. It feels a little like sealing a zipper storage bag.
As the barbs hold the feathers together, the wing holds the feathers in position. When all the feathers are held together to form a single shield, the wing catches a lot of air. Flapping such wings can carry a bird up into the sky and across a distance.
The wings work like sails on a boat. The sail are spread wide to catch the wind and propel the boat along. The sails are reefed to folded up to slow the boat. The jib can be moved so the boat can move forward in wind coming from different locations.
Vultures are fun to watch as they soar up in the sky. They do flap their wings to get up into the air. But after that they simply shift their feathers to catch or release warm air currents rising beneath their wings. To go up, the feathers gather so increase the amount of air they catch. To stay circling, the feathers are spread so not all the air is caught.
Wings spread flat catch the air. Wings pulled upward let the bird descend quickly. Wings pulled in close to the body let a bird like a hawk dive.
Braking is another important wing function. Hitting the ground at over a hundred miles an hour is not healthy. Instead curving the wings slows the bird down on approach to the ground or a tree branch. Perfect soft landings.
Feathers do wear out or get damaged. Each fall birds molt or drop the old feathers and grow new ones.
The days of market hunting of birds for their feathers spawned a law against having most bird feathers in your possession. I still pick them up when I find the old ones lying on the ground in the fall.
Birds are so untouchable and unapproachable. I can’t blame them. An approaching giant might be hungry and they have no desire to become a meal.
Picking up a fallen feather is a way to better appreciate the birds I see up in the trees and skies. Besides, a feather is a marvel itself.
Read more about vultures in “Exploring the Ozark Hills.” Visit the Shop to find out more.