Identifying Bald Eagles, Ravens, Crows, Turkey Vultures by Wing Pattern
Bald Eagle, Madeline Island, Wisconsin
Some Facts About Bald Eagles
I have lived in northern Michigan for twenty-nine years. It has been my joy to observe the rebounding of the Bald Eagle population firsthand. Today, I can go to my favorite natural areas and am almost guaranteed to see at least one Bald Eagle. Often I see two or more.
My son and I were kayaking on a small inland lake two years ago. We saw a large bird across the lake standing on a dead, fallen tree. We proceeded slowly and quietly. We came about one hundred feet from the bird and stopped. By then we knew it was an immature Bald Eagle. It did not yet have the white head and tail. Suddenly, but quietly, my son got my attention and pointed. I followed his direction and saw a mature eagle in a tree, then another, and another. I looked up and saw, directly above us, four more Bald Eagles. Seeing seven bald eagles at one time is still a record for me.
It is estimated that in the 1700s there were between 300,000 and 500,000 Bald Eagles in the lower 48 states. Over the years, due to hunting and pesticides, the population dwindled to an all time low of 500 nesting pairs.
DDT, or dichloro-diphenyl-trichloroethane, is a pesticide that was developed in the 1940s and used by the military to fight malaria, typhus, body lice and bubonic plague. DDT was later used in agriculture, but was banned in 1972 in the United States. The chemical was concentrated in animals at the top of the food chain. DDT caused Bald Eagles to produce eggs with extremely thin shells that could not bear the weight of the incubating parent. Many broke or simply never hatched.
By 1978, Bald Eagles were officially considered an endangered species. With the protection which that designation provided, along with the banning of DDT, the Bald Eagle population rebounded so that in 1995 they were removed from the Endangered Species list and considered a threatened species.
Today there are an estimated 70,000 Bald Eagles in The United States, and Canada. While there is much sadness in that story, there is also a great deal of joy and hope.
The Eagle and the Turkey Vulture (Click on thumbnails)Click thumbnail to view full-size
Silhouettes of Large Birds
Identifying Large Birds by Silhouette
Have you ever seen a large bird flying above you, and wondered if it might be a Bald Eagle? Most of us need to be close enough to these magnificent birds to observe their white heads and tails. There is another way to identify birds other than by color. A friend who has a bit of experience with raptors, tells me that the best way to learn to identify these large birds is by their wing pattern or silhouette, when they are soaring.
A bird soars when it stops flapping its wings and spreads them to catch the wind, thereby staying aloft. This is the best time to identify the wing pattern as it is silhouetted against the sky.
There are a few other large birds which also soar, so we need to be able to tell the difference. I will use the species of my area as an example. You might need to learn the wing pattern of a species that is particular to your area.
The large birds I see in northern Michigan skies which might be confused with Bald Eagles are Turkey Vultures, Crows, Ravens and Red Tailed Hawks, It might seem that it would be easy to discern crows, ravens and hawks from a Bald Eagle, but when these birds are flying high in the sky, with nothing else to provide perspective, it can be difficult to tell.
Comparisons of Wing and Tail Shapes of Bald Eagles, Turkey Vultures, Ravens, Crows and Red Tailed Hawks
Examples of Large Birds
View from below-straight on front and back; squared off at ends. Shape from front view-flat
Fan shape. Proportionately shorter than other large birds.
View from below-Curved leading edge; Long finger-like feathers at ends. Shape from front view-Wing bows downward to the middle and back up at ends.
Long and narrow. Longer than Bald Eagle's
View from below-bowed forward at middle then tapers back at ends. Long feathers at ends are straight out
Broad, fan shaped.
View from below-long feathers at ends taper back
Narrow, longer than Raven's
Red Tailed Hawks
View from below-bows out to middle and back toward end. Back follows contour of front.
Very long and narrow
Avoid Using Color as the Only Means of Identifying Bald Eagles and Other Birds.
As you attempt to learn to identify these large birds, try to get away from using color as the primary means of identification. Bald Eagles pass through a four year period during which they change dramatically. If you are looking only for a white head and tail, you will likely misidentify the younger birds.
In their first year, the Bald Eagle is very dark brown. Over the next three or four years it will slowly lighten in color and the underside will be a mottled brown and white or white with brown flecks. In years four and five, the characteristic white head and tail develop.
So you can see how coloring alone might lead you astray when identifying these birds. The shape of the bird is a more trustworthy method and can be verified somewhat if the bird comes close enough for you to observe its coloring.
Immature Bald Eagle and Mature Bald Eagle
I hope this gives you a little more knowledge to draw from as you watch the skies and observe these beautiful, majestic creatures called Bald Eagles.
In the comments section, let us know where you live and if you have seen an increase in the number of Bald Eagles in your region.