From the Contact Station March 2024

A Lesson from a Young Bird

In about a year, I will be able to say I have been birding or have been a birder for fifty years. My interest in birds came earlier than that. One of my friends in my college biology class was a birder and was always talking about wonderful birds he had seen. We called him Hawk. So, I took an ornithology class in the spring of 1975. It has been a tremendous learning experience ever since.

Everywhere I go, I bird. I have gone down the block and around the world to bird. I live in Ridgefield to be near a national wildlife refuge where I can bird. I consider myself a good birder, but not an exceptional birder. I am still learning. The last few weeks have provided an exceptional learning experience. We have had a large and overall dark eagle flying around the refuge for about a month. I’ve run into several friends who have mentioned spotting an eagle that looked like a Golden Eagle. I had seen it too and that was also my thought.

We were doing our twice-monthly winter goose count when I got a text message that the eagle in question was perched in the twin trees between Rest Lake and Swartz Lake. Since I was doing the River S route for the count, it was just a matter of getting there to get a good look at this bird. I had seen it twice and both of those times were low flybys with little to go on but ‘wow, was that a Golden?’ I approached the perched eagle slowly stopping along the road past #12. I didn’t want to scare it off before I could get within phone camera range. I spent some time looking at it high up in the thick branches of the tree along Swartz Lake. I inched up to get a better look. It was not out of the question that it could be a Golden. After a while I was able to get close enough. Looking up through my sunroof I was able to get a nice shot, if not exactly a clear shot. Thinking it was what I thought it was, a Golden Eagle, I had a bit of a celebration with a friend. At that point we were discussing nesting and the eagle population. And he told me of a place where there was an active nest that I didn’t know about. So I deviated from the goose count just long enough to be shown a Bald Eagle nest which can be viewed at the southern end of the auto tour in the big bare cottonwoods just beyond the south dike.

After the introduction to the new nest, I went back to the tree to take some more time looking at the eagle in question. And I found it, not in the tree, but sitting on the ground in the field just past #13. It was having a stare down with the Northern Harrier. Was it wondering if the harrier had caught a mole or vole and probably thinking about stealing it? I know who would have come out first in that duel. The harrier was rather vocal and eventually flew off then circled back over the eagle still on the ground. I was close enough to get some reasonable additional shots of the eagle. Two other birds stopped by the contact station later in the day to discuss differences between Bald and Golden Eagles. We all had similar impressions and questions. If we had a Bald, it was probably a Juvenile, first year bird. If it was a Golden, harder to say, but probably younger.

Bald Eagles change appearance through their first four years until they get their stunning white head and tail as an adult in their fifth year. As they move through their molts, to me the young birds look like someone flicked a paint brush full of white paint at them and scattered white spots here and there in no particular pattern. Although somewhat variable in amount, the white on the underwing of the Golden Eagle is organized into patches where the flight feathers have white bases. As the Golden Eagle ages, some of the body and wing feathers begin to appear mottled, dark and light, because of the mixture of new and old feathers.

A great way to distinguish the Golden from the Bald eagle is to look at the silhouette. Unfortunately, none of the sightings, and certainly not the photos, provided a good view for the comparison. Bald Eagles are always proportionately short-tailed and large-headed, whereas Golden Eagles have long tails and small heads. In addition, the Golden Eagle has long outer secondaries that produce a noticeable round bulge, or shallow ‘S’ shape, on the trailing edge of the wing. The trailing edge of the wing is straighter for Bald Eagle giving it what is often referred to as a washboard look.

Also, Golden Eagle has a shallower wing beat than a Bald Eagle but that is hard to assess. However, if it pauses to soar the wings are held in a slight dihedral while a Bald Eagle keeps its wings flat. If you get a good view of a flight over the Refuge, you would probably be able to pick this out.

There is one other factor we had talked about. By now, Golden Eagles are probably thinking of nesting and it is not probable they are nesting anywhere around here. So that begs the question, what would a Golden be doing here at this time of year? According to WDFW, nests are situated on cliff ledges, rocky outcrops, large trees, or human made structures, such as power poles and transmission towers. Most eastside nests (80% of the breeding populations) are on cliffs, while westside nests are above timberline or in very large trees that border on extensive clearcuts.

All that is good information, but none of it was helpful in this situation. I thought about using Merlin to identify the eagle. But Merlin said it was a Peregrine. Well, I knew that wasn’t correct. Probably a critical comment on my photography skills. So, I shared the photos with another friend that I consider an exceptional birder. She studied the photos and came up with an answer I think is spot on.

Ok, this is what I see:

As we already discussed, the bill protrudes quite a bit, consistent with Bald.

The cere is black, expected in a 1st winter Bald, but should be yellowish in a Golden.

The tarsi are bare (seen in the flight photo), these would be feathered all the way to the foot in a Golden.

The “block-head” appearance with the rear crown feathers somewhat erect is a characteristic of Bald Eagles.

I would expect some gold feathers at the nape showing in a Golden, even in this lighting, but I see no evidence of them.

I can’t really get a good impression of the outer secondaries from these pics, so that doesn’t help. 

The white scattered spotting is consistent with a first winter Bald, but not with any age Golden.

Even if we ignore the bill and plumage characteristics, I would say the bare tarsi alone would help rule out Golden. 

So, with this bird, the devil was in the details. When perched, Bald Eagle often holds its head feathers semi-erect, making the head appear ‘blockier’ than that of Golden Eagle. A young Bald Eagle has a darker (blackish) bill and cere (where the nostrils are) than Golden Eagle, which has a yellow cere. At close range, the Bald Eagle has naked tarsi, in contrast to the feathered tarsi of the Golden Eagle. Even in the bad photo, you can see that well. All useful details to discover the identity of what we have been seeing.

Wherever you are in your adventure with birds, there is always time to learn something new. I often talk to people at the contact station about whether they saw a Golden or a young Bald Eagle. This month I learned a whole lot more about the details that can separate them. Talking with friends, following up on hunches, digging into bird books was satisfying. Even if the end result is not what you hope for, you’ll still be a better birder for the effort. (Big thank you to Cindy McCormack from Vancouver Audubon.)

-Susan Setterberg, Contact Station Volunteer
images by Susan Setterberg of Juvenile Eagle, February 2024