This is bird note.

One of the most difficult skills to pick up when you start noticing birds is how to identify one in flight.

You have to sort through a series of visual clues all at once, at high speed, silhouette, wing shape, how fast it flaps, dark and light patterning.

An experienced birder will take in all these and other clues.

So, if you hang around long enough, you might hear something like, look, a hawk must be a Cooper's hawk. It has that giz.

In other words, it has all the telltale signs.

But where did this bit of bird-watching slang originate?

One explanation takes us back to World War II when trained spotters scan the skies and identified airplanes by a coded system called General Impression of Size and Shape.

Or, G-I-S-S.

Each plane, enemy or friend, had a G-I-S-S.

Birders simply borrowed the concept, spelling the word by its sound, giz.

Makes perfect sense.

Except some birders apparently use the word as early as 1920, which has led to speculation that it's derived from the word giz.

Whatever the origin, getting a general impression of the size and shape is a good start for identifying a bird in flight.

For Bird Note, I'm Mary McCann.