As we go into prime “eagle watching” season here in northern Utah I thought it might be timely to present a guide that would be helpful in aging Bald Eagles as they progress through the 5-6 year process of becoming adults. Many of these younger birds are mistakenly identified as Golden Eagles by the general public.
Eagles that have not reached the adult stage are referred to as immature, juveniles or sub-adults. Plumage stages are highly variable, depending on molt sequence, age and timing so other factors like iris and beak color are also taken into account when estimating age. Eyes gradually change from dark brown to yellow while the beak goes from blackish-gray to yellow.
 1/4000, f/8, ISO 500, 500 f/4, not baited, set up or called in
 The adult Bald Eagle is unmistakable with its distinctive bright white head and tail contrasting with the dark brown body and wings.
 1/200, f/6.3, ISO 800, 500 f/4, 1.4 tc, not baited, set up or called in
But juveniles present very differently than adults, especially in the early stages of development. This very young bird is barely fledged and was still hanging around its nest in sw Montana. Notice that the plumage is dark brown throughout, though they may have some white or pale mottling at this stage - especially on the underparts. Both eye and beak are very dark.
 1/2000, f/6.3, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
This is a first year bird during winter.
1/800, f/8, ISO 500, 500 f/4, natural light, not baited, set up or called in
A side view of the same bird as in the previous image. The warm, early morning light gives it a bit of a golden glow. This stage is often confused with the Golden Eagle (Golden Eagles have feathered lower legs or tarsi while Bald Eagles do not).
 1/3200, f/8, ISO 500, 500 f/4, not baited, set up or called in
Plumage after the first year becomes increasingly variable. There is more mottling and the beak and cere are becoming less dark.
 1/1600, f/6.3, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
 The iris is beginning its transformation to yellow and there’s also some yellow at the base of the beak.
 1/1250, f/7.1, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
As plumage stages develop through the second and third years the tail becomes whiter with a dark terminal band and more white appears elsewhere. The beak is less dark and as the head becomes lighter generally it leaves a darker “eye stripe”.
 1/1000, f/8, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
The eye is becoming more yellow and the eye-stripe quite distinctive.
 1/1600, f/8, ISO 500, 500 f/4, not baited, set up or called in
The beak becomes more yellow (though not as bright as in the adult). Some birds at this stage (like this one) exhibit a few secondary flight feathers that are longer than the rest at the trailing edge of the wing.
 1/640, 7.1, ISO 800, 500 f/4, 1.4 tc, not baited, set up or called in
By the fourth year (though there’s much variation) the head is mostly white with some dark flecking around the eye and forehead near the cere. The tail now lacks the dark terminal band and the beak is nearly completely yellow.
 1/1600, f/6.3, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
 This bird is very nearly in full adult plumage. The tail is now bright white but there remains some dark flecking on the head.
 1/1250, f/7.1, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
A fully mature adult.  Both head and tail are now completely white with overall dark brown plumage elsewhere. This bird has fish blood on its beak and if you look closely you’ll see that it has a “blown eye” (misshapen pupil, possibly due to injury).
 1/1600, f/8, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
 Here you can compare three plumage stages of Bald Eagles in one photo.
 1/800, f/11, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
 An adult and a young juvenile.
 1/1000, f/11, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in
An adult on the right, a first year bird on the left and an intermediate juvenile in the middle with some interesting mottling.
If the weather and many other factors cooperate, the month of February often provides some fantastic opportunities for eagle watching in northern Utah, especially at some of the wetlands around the Great Salt Lake like Farmington Bay NWR.  Hopefully some will find this post useful in helping them to appreciate these magnificent birds even more.
Ron
Note: It’s possible that the last two images in this series were baited. I learned after the fact that on some days photographers had been moving some of the carp the eagles were eating to more photogenic locations. I don’t believe the birds in these two images were baited, but it’s possible…
[…] eyes. Based on what I have read online (a nice photographic summary of aging Bald Eagles is at http://www.featheredphotography.com/blog/2013/01/27/a-guide-to-aging-bald-eagles/), I am guessing this is a first year bird, due to the dark iris and fairly dark […]
[…] In their first two years Bald Eagles are dark feathered and have dark eyes and beak; each succeeding year for the next three, the head feathers and tail feathers gain a little more white, and the eyes and beak become paler and finally yellow. Â Click on the photo below to see Ron Dudley’s fantastic photographic essay on “A Guide to Aging Bald Eagles“. […]
Ron, thank you for posting this astoundingly beautiful and informative illustration of the plumage stages of the Bald Eagle.
[...] Dudley gives us a photographic guide to aging Bald Eagles at Feathered [...]
What a beautiful set of pictures! Ron, your descriptions have helped us quite a bit in identifying the eagles on and around our Florida lakefront. We are truly blessed to have them here and appreciate your work very much.
We have a cabin on an island in a backwater bay at the very northern end of Georgian Bay (lake Huron). Canada geese are moving in (unfortunately). Earlier this month I observed an interesting event. I had flush the goose family out of a marshy shore unintentionally as I landed my boat. The family moved across the channel and hung around for a while. I have grown accustomed to the sound of the geese “talking” to their young – sort of like background music. But suddenly their vocalizing changed dramatically to a deep low honk, which caught my interest. I looked up and saw a bird of prey flying low over their heads. As I am not an experienced bird watcher, I could not identify the bird immediately, but my instincts told me it was a young eagle. I saw it again this morning, taking off from a nearby island, about 200 meters away. Your images helped me recognize it as being a young eagle. Thanks!
As a wildlife painter and nature lover, your photos and comments are priceless. We see plenty of baldies here on the Hudson , esp. In the winter and their numbers are increasing. How does the eye color of the golden eagles change as they age? I’m working on a watercolor of a juvenile golden now that has dark eyes. Will they change and get lighter like the eyes of the baldies? What will they change to? I notice a lot of variation in the “golds” on the napes of various goldens. What are typical colors? The particular juvenile I’m working on now, has a very light nape or mantle, almost off white ( it has “long pants” and is definitely a golden). J Will it change as he/she ages? Thanks for your great photos and for sharing them. Excellent work!!!t
Patty, The eyes of juvenile Golden Eagles are dark brown while those of adults can be dark brown, light yellow with flecks of gold and brown, hazel and a few are almost white. Lots of variability. Solid brown or hazel are most common.
I’m less sure about any nape color changes as these eagles mature. Sorry…
Thank you Ron!!! From egglet to adult they’re beautiful.
It is great to see all the ages. I hope you can get Golden Eagle pictures the same way.
Thanks for all the valuable information. We are in South Rustico, P.E.I., Canada and today saw a second siting of what we thought was a Golden Eagle. It was truly a magnificent size and through the binoculars I could see its mottled amber breastfeathers. Comments to mine on Birding PEI told me that only a few Golden Eagles have been sited in the past century so Im probably mistaken. We live right near the St. Lawrence River and see quite a few Bald Eagles in groups.
Thank you, Ron. Saw a juvenile/subadult yesterday with really interesting mottling. Now I know it was a young bald eagle. I live along the Colorado River corridor so get to see eagles often, especially in the winter because the river flows freely here during the winter. I was in Grand Junction yesterday and much of the river is solid ice on top. Saw no eagles there. That area is for viewing at times other than winter.
Ron: fabulous guide, thank you. Any way you could make it available in printable form? I would love to be able to take it with me when I am out watching/photographing eagles. Thank you so much!
I love this! Thanks so much for all the info! The last 3 years, we have had a “family” of Bald Eagles close to our house, in the wintertime– We live in Illinois– close to the river– I enjoy seeing all of the Bald Eagles, now I feel like I will be able to tell the age of the younger ones now!
Thank you for the wonderful write-up / descriptions. Your pics are just absolutely stunning!
Ron, this was so helpful to me. It’s only since I moved to the Northwest that I’ve had the privilege of watching eagles. I know adults and young juveniles, but the intermediary, mottled plumage throws me in terms of aging the eagle. This is great. Most of the subadults I see around here look like your Photo #5. I rarely see the transitional stage closer to full-adult plumage. Or perhaps, I’m thinking it’s an adult but there’s still transformation occurring. The last shot … the subadult with the white … what a gorgeous bird. I wonder if any of the eagles I’ve seen here were baited prior to my arrival and I just didn’t know it? I recently learned of a guy on one of our river systems who does this, but I haven’t been up to his neighborhood. I will keep that in mind when I see photogenically placed fish, that it might not have been a natural occurrence.
Ron, I was guided here by another BE-watching friend– what a fabulous sequence, and how fortunate you are to have access to such numbers of the bird! Thanks for posting!
Welcome, Chris, and thank you. Yes, I am fortunate indeed to have access to lots of eagles for part of the year.
This is both wonderful in terms of both photos and commentary! Thanks so much for sharing!
Thanks, Charlotte
Ron, your pictures are amazing! Thank you so much for the detailed chronology of the changes! We often get them in for rehab here in Klamath Falls, OR, and I typically rely on the feathering on the legs to determine BAEA vs GOEA, but these pictures are a HUGE help with not only determining which it is, but with age. Thanks again!
Thanks very much for the feedback, Liz. I’m very happy to hear that these photos and info will be helpful to you in your work with the eagles.
Thanks so much for this post and great pictures. I seldom get to see eagles but sometimes volunteer at refuges where I need to know this information in order to give visitors a better time and greater understanding of the birds they are seeing.
I’m delighted to hear that some of this info might be helpful to you in your volunteer refuge work, Marilyn. And I applaud you for doing it – what you’re doing is a very valuable service for your visitors and for the birds.
Once again, Ron, great post and excellent photography. Keep up the great work!
Thank you for the encouragement, Ken!
Thanks so much Ron for this information must of it i already knew but I love to read about this magnificent bird. Where i am from we have a dam on the Susquehanna river that is a major feeding spot for hundreds of eagles of all stages .In the last weeks of Sept all of oct,nov,and dec we can be assured to see between 50 to 150 birds a day.If you are not to booked up i would love to invite you for next years season.You can find me on Fred Miranda or flickr Thanks again for this info
Thanks Michael, very much. I appreciate the offer but I don’t fly well and it’s too far to drive. Thankfully we usually have lots of these birds Dec through about March 1 (last year was an exception though…)
What a magnificent journey through the stages Ron, I knew you had some Bald Eagle treasures and more to come!
LOL! I TOLD you I’d likely post some more Bald Eagles in the near future, Maria…
What a wonderful tutorial! And timely, too, as we’re seeing lots of eagles on the nest locally and every trip I’ve taken this year I’ve seen at least one immature Bald Eagle.
Thank you so much, Ron!
Thanks Wally. As I type I’m also watching a literal blizzard outside my window so I’m having a hard time imagining birds of any kind “on the nest”. Sure hope you’re enjoying them. And your much better weather…
When I first saw the title of this entry, I thought, guide to old eagles? LOL. Really nice shots and info, thank you. It’s getting to breading season here in the San Antonio and Corpus Christi areas, and I’m very much looking forward to the awesome waterbird and pelagic raptor plumage we’ll be getting. Thanks again. Lane
Lane, I actually thought of that possible interpretation of the title but chose to go with it because most others I thought of were either too long or less accurate in depicting the content.
Hi Ron. How wonderful to be able to see the different stages of the Eagle, your beautiful photos and your descriptions in one page. I follow two Eagle cams and was wondering if I could share this link with them. A lot of people do not realize the transformations this amazing raptor goes through before full adulthood. They only get to see the chicks grow into jurvies at which point they fledge. This would make for a wonderful teaching tool. Thank you.
Of course, share away Debbie. And thank you.
Ron, this is SO informative! As usual your photos are amazing and in conjunction with your focus on writing about the behaviors of these wild creatures, I’m hooked.
Thanks so very much!
I’m glad you find the info helpful, Blue. Thanks for tthe feedback.
Thanks Ron that was great and the photos incredible as a norm for you.
Thank you, Earl.
Thanks for explaining and showing the stages of the juvenile bald eagles, and the awesome photos!
You’re very welcome, Angie.
Yes, thank you! We have been fortunate to watch this progression in Teasdale as the eagles that nested there for several years came back each season. But these pictures really make it easy to identify the different stages. Your blog is fantastic!
Tana, I’ll bet you do become attached to those Teasdale birds since they return every year. It’s gratifying to know more eagles are nesting in Utah now. I remember back in the 70′s when the only breeding pair left in the state was at Fish Lake.
Thank you Ron for the beautiful chronology ! It must take an immense amount of skill, instinct, and sometimes just luck for the Bald Eagle to reach the fully mature stage and live long enough to breeding age.
Thank you for taking the time and explaining the various phases.
John, Watching these birds trying to scrape out a living while they’re down here in the depths of winter always reminds me of the same thing – the long odds they must have of ever reaching breeding age.