by NEC Education Director Scott Mehus

Raptors seen in the Winter months with a dihedral should stop traffic! Why, you ask? That raptor could be an unseasonably late or early Turkey Vulture, wintering Golden Eagle, Rough-legged Hawk, or Northern Harrier -- all birds worth getting out of your toasty warm car to see!

A dihedral is when the wings are held up against the horizontal level like a shallow “V” or “U.” A turkey vulture has a very pronounced dihedral “V,” whereas a golden eagle has a slight “V” formation which is unlike the flat as a board profile of a soaring bald eagle.

When I observe a Golden in a full soar, about 80% of the time I see it using a slight dihedral. Definitely not as pronounced as a Turkey Vultures classic dihedral, but much more than the Bald Eagles’ “flat as a board” profile.

The best place to look for Goldens in Bluff Country are areas with several goat prairies. Goat prairies (or dry prairies) are located on the South and West facing sides of the bluffs, they are areas that get a lot of sunlight and therefore dry out more quickly than surrounding areas. Trees, with the exception of Red Cedar, do not grow well here because of the lack of moisture. Prairie grasses thrive in this type of habitat, but unfortunately, in the age of extinguishing all natural fire, Red Cedar is taking over most goat prairies. Goat Prairies get their name from the days when the bluffs were grazed and theoretically only goats could could feed on these steep slopes. Goldens like to cruise along the back side of the bluff and come, stealth-like, up and over these Goat Prairies to surprise prey feeding out in the open, attacking before the their target has a chance to reach cover.

Unless a Golden is found soaring, finding one will be much like looking for a needle in a hay stack. They just do not stick out like a sore thumb like Balds do in the landscape. Balds typically pick prominent limbs on the outer edges of the of the tree canopy to perch upon, whereas Goldens typically perch within the tree’s canopy, often times close to the center of the tree. If, while driving through bluff country and scanning the silhouetted bluff line, you spot a large raptor perched along it, nine times out of ten it will be a Bald and not a Golden. BUT, to be safe, still check it out!

Once a soaring Golden is found, notice the almost headless appearance of the bird soaring over you, very similar to a Turkey Vulture. Obviously it is not headless, but the projecting head is about one-third the length of it’s tail, and compared with seeing a Bald overhead, which has as much head projecting out in front as there is tail sticking out behind, this gives the Golden a headless appearance. Be aware that in certain light conditions (such as backlighting or overcast days) the Bald’s head is very difficult to see and could be mistaken for a “headless” Golden.

While looking at the somewhat projecting head you should note at the nape of the bird the golden color from which the bird gets its name. The nape is located just below the crown of the birds head and ends just at the upper end of where the bird’s shoulders are. The color can vary from straw yellow to a whitish bronze, and all age classes will have this color on the nape. Sometimes this can be such a bright golden color that it appears white-headed at a distance, so always thoroughly look over each bird.

Now that you’ve seen the nape color, let’s move on down the back to try to determine if the bird is a juvenile or older.

On a juvenile’s back the color will be all brown, whereas on all birds that are over one year of age there will be a tawny-colored bar on each side of the birds back; these are called upper wing coverts. It’s very similar to the light-colored bars seen on Red-tailed hawks, because on both it appears as if the birds have been wearing a backpack for too long has worn and faded the feathers in this area of the bird’s wing. This is a great way to determine if the birds are juveniles or not. Even though bald eagles may occasionally have some markings on the back, they will not be as precisely shaped and neat looking.

Watching a bird soar overhead, notice that the wings pinch in at the body along the trailing edge of the wing. This makes the secondaries bulge out and gives the wing more curvature, different from the unpinched straight plank-like trailing edge of a Bald. This gives the impression of a very large and dark Buteo (or common buzzard).

Another feature that gives one the impression of watching a large Buteo soaring over is the very “uneagle-like” tighter circle that a Golden makes in flight. Bald Eagles make a very wide circle, almost like they’re pulling a trailer and making a left hand turn onto a roadway. A Golden’s turn is more like that of a Red-tail, still pulling a trailer on that roadway, but more like a camper versus a semi-trailer.

When a Golden is observed flapping its wings, it will be unlike the deep, stiff and powerful flap of the Bald. This also gives the impression that the bird is lighter in weight. The motion of the flap is also shallower and centered at the wrist rather than along the whole arm; again, reminiscent of a Red-tailed Hawk.

Several times each week during the winter season I have people telling me that they’ve seen a Golden Eagle along the Mighty Mississippi River. Using my best teaching skills and tact I explain to them that in the past fifteen years of watching Eagles along the river. on only two occasions have I seen a Golden Eagle within 30 feet of Old Muddy!

I do see how that misidentification happens though, especially when you see a small male Bald Eagle, who may weigh in at eight pounds, sitting next to an immature female Bald Eagle who may weigh in at eleven pounds. That’s enough right there for confusion to set in, but then add the fact that immature raptors in their first year of life have longer flight and tail feathers -- up to an inch or more in eagles -- they are BIG and look VERY different to the inexperienced eye. So, accordingly, the survey routes are not along the Mississippi itself, instead located in the bluff country.  Someday when we have more observers, we may do some looking along the river, just to be sure -- after all, we want to have data to show that they are not along the river.

Donald, the NEC Golden Eagle

When observing up close or with a scope, the heavy, massive bill of the Bald should stand out in contrast to the Goldens small beak (which almost looks too small for the bird). While looking at the beak, also notice that on the Golden the beak is dark on the outer tip and pale blue on the inner half, which is very different than the Bald’s all-dark black beak, which they have the first year of life (the only year that they might be confused with Goldens, after which both the bill and body show a lot of mottling and should not be a point of confusion).

Golden Eagles are exciting to observe in their natural habitat. Keep your eyes open and you’ll be lucky enough to see these majestic creatures in action.

Turkey Vulture photo credit: Wing-Chi - Creative Commons Atribution ShareAlike

Golden Eagles Soaring photo credit: US Fish and Wildlife