Wednesday, October 21, 2015

Fabulous Feathers

We learn at a young age that birds have feathers. Feathers help a bird to fly.  While I’m not about to refute that fact, it must be said that there is so much more to feathers that makes them truly fascinating.

First of all, there are seven different kinds of feathers.  There are wing feathers, tail feathers, contour feathers (which cover the bird’s body), semiplumes (slightly fluffy), down feathers (REALLY fluffy), filoplumes and bristles (long skinny whisker-like feathers).  Each different kind of feather serves a different kind of purpose.
Keeoo the Augur Buzzard displaying the overlapping pattern of wing feathers and the rudder-like tail feathers (photo: Gay Schroer)

Wing feathers help form the shape of the wing into an airfoil to gain lift, and tail feathers act as a rudder to help a bird steer.  Of course, this assumes that the bird in question can fly at all.  In some species, such as the ostrich, flight is not an option.  Oftentimes, when this is the case, the wing and tail feathers are not stiff and flat, but have evolved to become more ornate for use in territorial or courtship displays.
Another view of how Keeoo's wing feathers overlap (photo: Gay Schroer)

Contour feathers form an interlocking, overlapping pattern over the bird’s body.  This helps to streamline the bird…and keep it waterproof.  Thanks to the pattern of the contour feathers, only the waterproof tips are exposed, allowing water to bead up and roll right off of the bird.  This is especially important in waterfowl, which would otherwise be soaked and cold.
A Snowy Owl is a perfect example of the insulating properties of feathers--even the bottoms of their feet are feathered (photo: Gay Schroer)

Semiplumes and down feathers are located underneath the outer feathers, where their fluffy barbs act as insulation.  The delicate fluff on these soft feathers creates small pockets of air next to the bird’s body.  These pockets of air under the contour feathers help insulate and keep the bird warm as outside temperatures cool down.   Down feather coats and comforters keep us so warm the same way.
A White-faced Barbet (Photo: wikipedia)

Filoplumes and bristles hardly look like feathers at all.  They have no barbules branching out from the central part of the feather, also called the rachis, so they resemble whiskers more closely than feathers.  This is rather appropriate, since the purpose they serve is similar to that of whiskers.  Filoplumes, which have teeny-tiny barbules at the very tip of the feather, help to sense the position of the contour feathers; and bristles, which have almost no barbules at all, are often found on or around the bird’s face.  Bristles may act as whiskers but also likely serve to protect the bird’s eyes and face, much like our eyelashes.

So yes, birds have feathers.  One could leave it at that, but why on earth would you want to, when there is much more to be learned once you delve into the fascinating and fabulous world of feathers?

Submitted by World Bird Sanctuary Naturalist JoHanna Burton

Editors Note:  The World Bird Sanctuary, and the blog in particular, are sad to say farewell to Naturalist JoHanna Burton who is leaving us to move across the country  We wish her godspeed and know that with her strong work ethic she will do well in any future path she chooses.

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