Sunday, January 1, 2012

What Can A Wing Tell You?

Wing shape

As you observe the birds around you while walking through the forest, sitting in your yard or visiting the World Bird Sanctuary, you will notice that bird wings come in many different shapes and sizes. 
 The above silhouettes illustrating different wing shapes
You can tell a great deal about a bird’s lifestyle just by looking at the shape of its wings.  The variation in wing form is due to the different uses each bird species has for these marvelous appendages.  Some birds need to soar for long periods of time.  Others need to use their wings for very rapid flight.  Still others need wings that allow for agility so they can evade predators or avoid running into trees.
 A wild Turkey Vulture soaring on the thermals
The next time you are outside, see if you can spot one of the many Turkey Vultures found in our area.  You will notice that they flap their wings very rarely. Using very broad wings with long, slotted primaries (furthest feathers from the body), they can ride on the rising thermals.  That way, they will expend as little energy as possible while they searching for carrion below.
Millenium, a young Peregrine Falcon, displays her long pointed wings  
In contrast, falcons can’t just cruise the region in search of ready-to-eat meat.  If a falcon had broad wings like a vulture, it would fly too slowly to catch its prey.  If a falcon wants to catch, for example, a pigeon, it needs long, pointed wings, which give it the capability of high-speed dives.  The Peregrine Falcon’s wing shape allows it to reach record dive speeds of well over 250 mph! 
Trucker, a Swainson's Hawk, displays his more rounded wing shape 
Raptors in the accipiter family, such as the Sharp-shinned Hawk and the Cooper’s Hawk have short, rounded wings. Their wing shape gives them the capability of explosive bursts of speed and the agility they need to maneuver through their forest homes and catch other birds.  Wing shape is an important adaptation that is a reflection of the bird’s way of life.

The next time you visit the World Bird Sanctuary pay particular attention to the shape and size of the wings of the different birds on display.  If you’re lucky you may see them extend their wings in a nice big stretch or flap.  See if you can guess what kind of lifestyle their wing type is suited for.

Submitted by Leah Sainz, World Bird Sanctuary Naturalist/Trainer

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