Flight silhouettes of birds: how to tell the difference

There are certain times when it is incredibly easy to mistake one bird for another, especially if all you see is the bird's silhouette.  Typically we see silhouettes when the light is bad such as at dawn or dusk, or on a cloudy day.  Fog, smog or smoke from a forest fire will also make it difficult to see color.   Sometimes however, it is merely the angle of light that is wrong and / or the distance of the object that you see.  A good example is the height at which a bird flies, the greater the height, the smaller the bird appears to be and the less of it's color you are likely to see.



So how can you positively make a distinction between a Raven and an Eagle, for example, or tell one hawk from another, when all you see is a silhouette?

Take for instance an Eagle mistaken for a Raven.  I made that error once while I was standing at the bus stop on a cloudy day.   I was only half paying attention to the bird and thinking it was likely a Raven, when I took this picture above.  As it happens the next day I did in fact take pictures of Raven's in flight and was well aware of it, because the Ravens were calling out to one another.   I didn't realize my mistake with the Eagle until I loaded these pictures into my computer a few days later.

Raven in the distance

Now some Ravens are not that much smaller than Bald Eagles when their wings are spread, particularly those in Alaska.   However, although both birds have broad wings, the shape of the Raven's tail is very different from that of an Eagle.  As you can see in the picture directly below, the Raven has a wedge shaped tail. Raven's also have "fingers" at the tip of their wings which you may or may not see when they fly.  If you click on this picture to enlarge it you will see them.

Raven as seen from below

Am I ever glad that I have a habit of taking pictures of birds no matter what the conditions, because as I was viewing the pictures of what I thought to be all Ravens, it came to me suddenly that there were differences in the flight silhouettes.  So I went back and zoomed in on the first couple of pictures to discover with both shock and surprise that I had two totally different birds.  At first I felt kind of foolish, but eventually I realized that there was a valuable lesson to learn from this mistake.   Which is what brought me to writing this post.

Take a close look at the next picture on the right, which I cropped for you.  You will notice patches of white on the underside of the wings, which is the first clue that this is not a Raven.   The second thing you should notice is the curve at the front of the wing, near the tip, and  the way the wings are held when compared to that of the Raven above.  The third, and equally important difference, is the tail which has a straight edge and so appears somewhat shorter.  A little research on Eagles, both mature and juvenile, brought me to the conclusion that this is a picture of a mature Golden Eagle.  This is what makes this aspect of my now obvious error somewhat exiting, and I ended up being positively thrilled to have these pictures of a Golden Eagle, despite the fact that they are only silhouettes.

As exciting as that is, it is even more exciting to have uncovered the means of identifying bird silhouettes and eliminating previous frustrations involved in being unable to do so.  The differences that I pointed out to you  in this post are just some of the ways I have discovered in which to positively identify a bird's silhouette.  I will write more on this topic soon.

More information on the Golden Eagle and the Raven can be found at the following links:

http://www.desertusa.com/mag99/oct/papr/raven.html
http://animals.nationalgeographic.com/animals/birds/golden-eagle.html

As always enjoy,

Susan