A Guide To Aging Bald Eagles And How To Distinguish Immature Bald Eagles From Golden Eagles

Almost five years ago (1/27/13) I published a post entitled “A Guide To Aging Bald Eagles”. With over 71,000 views to date that post has been my most popular so I decided it was overdue for an update and enhancements. For this version I’ve made the following changes:

  • much of the text has been rewritten for purposes of accuracy and clarification
  • three images have been added
  • a section about distinguishing immature Bald Eagles from Golden Eagles has been included
  • formatting has been cleaned up and the title modified

 

As we approach 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 plumage stages of becoming those glorious white-headed and white-tailed adults we’re all so familiar with. And since many immature Bald Eagles so strongly resemble Golden Eagles I’ve included information and photos that should be helpful in distinguishing the two.

Raptors, including eagles, that have not reached the adult plumage stage are referred to as immature. Those in their first plumage stage are called juveniles and the term sub-adult is used to refer to any plumage stage between juvenile and adult. Depending on molt sequence, age and timing plumage stages are highly variable 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 as they mature.

 

bald-eagle adult 2172

 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.

 

 

bald eagle 0320 juvenile ron dudley

 1/200, f/6.3, ISO 800, 500 f/4, 1.4 tc, not baited, set up or called in

But immature Bald Eagles present very differently than adults, especially in the early stages of development. This juvenile is barely fledged and was still hanging around its nest in southwest Montana. Notice that the plumage is dark brownish-black throughout, though they may have some white or pale mottling at this stage especially on the underparts. Both eye and beak are very dark.

 

 

bald eagle 7024 ron dudley

 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. There’s already some color change in the eye.

 

 

bald eagle 6590 ron dudley

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 that wouldn’t normally be seen.  This stage in particular is often confused with the Golden Eagle.

 

 

bald eagle 2298 ron dudley

 1/3200, f/8, ISO 500, 500 f/4, not baited, set up or called in

Plumage colors after the first year become increasingly variable. There is more white mottling ventrally and the beak and cere are becoming less dark.

 

 

bald eagle 7599 ron dudley

 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.

 

 

bald eagle 2363 ron dudley

 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 sub-adult 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 it generally leaves a darker “eye stripe”.

 

 

bald eagle 0226 3rd year ron dudley

 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 is quite distinctive and often similar to that of an Osprey.

 

 

bald eagle 1297 ron dudley

 1/1600, f/8, ISO 500, 500 f/4, not baited, set up or called in

The beak is becoming 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.

 

 

bald eagle 8499 ron dudley

 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) they’re in transition from immature plumage to full adulthood. The head is mostly white with some dark flecking especially around the eye and forehead near the cere. The tail now lacks the dark terminal band and the beak is nearly completely yellow.

 

 

1/2500, f/8, ISO 500, not baited, set up or called in

A closer look at the same bird allows a better view of the detail of the dark flecking and the beak and eye color at this stage.

 

 

bald eagle 3237 ron dudley

 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 a small amount of dark flecking on the head.

 

 

bald-eagle-3875 ron dudley

 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).

 

 

bald eagle 1454 ron dudley

 1/1600, f/8, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in

Here we can compare three plumage stages of Bald Eagles in one photo – a sub-adult on the left, a juvenile in the middle and a mature adult on the right.

 

 

bald eagle 9847 ron dudley

 1/800, f/11, ISO 500, 500 f/4, 1.4 tc, not baited, set up or called in

 An adult and a first winter juvenile up close.

 

 

bald eagle 9961 ron dudley

 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 juvenile on the left and a sub-adult with some interesting mottling in the middle.

 

 

1/1250, f/7.1, ISO 640, not baited, set up or called in

One of the most common ID errors I see in the field is folks confusing immature Bald Eagles with Golden Eagles (the image above is of a Golden Eagle). Almost invariably novices will call any very large dark raptor a Golden Eagle while in most North American habitats it’s much more likely to be an immature Bald. Here are some guidelines that can be used to distinguish Goldens from immature Balds.

  • Golden Eagles have a distinctive golden nape (back of neck) that is usually easily seen in direct light and is completely lacking in Bald Eagles of any age.
  • Though it can’t be seen well in this photo the legs of Golden Eagles are feathered all the way down to the toes while the lower legs (tarsi) of Bald Eagles are not feathered.
  • Typical of most fishing eagles Bald Eagles have a very large bill, noticeably larger than that of Golden Eagles.

There are other more subtle plumage differences that I’ve chosen not to include here.

 

 

1/1600, f/7.1, ISO 500, not baited, set up or called in

Another helpful tool is behavior and habitat. Golden Eagles very rarely feed on fish and as a result they’re less likely to be found in aquatic habitats so if the eagle you’re attempting to ID is associated with fish, fishing or aquatic habitats it’s very likely to be an immature Bald Eagle. That’s not an absolute guarantee but it’s a helluva clue.

 

For many of us Bald Eagle season is almost upon us so I hope these tips and guidelines will be helpful to my readers. After all, no one wants to misidentify an eagle of either species!

Ron

Notes: 

  • For this updated version I’ve used several resources for guidance including “Birds Of North America Online”, my own photos and knowledge and friend and raptor expert Jerry Liguori’s excellent book “Hawks From Every Angle – How To Identify Raptors In Flight”.
  • It’s possible that the third and fourth photos from the bottom 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 feeding on to more photogenic locations. I don’t believe the birds in these two images were baited, but it is possible.
  • I believe all of the images in this post were taken with my Canon EF 500mm f/4L IS USM lens (either version I or version II) though I ran out of time to verify. Most of the photos were taken at Farmington Bay WMA in northern Utah.

 

 

77 comments to A Guide To Aging Bald Eagles And How To Distinguish Immature Bald Eagles From Golden Eagles

  • Roselia Panacci

    They are Great Photos. I have been watching -Southwest Florida Eagle Cams -Since Last Year. Harriett and M15 – Great Bald Eagles/Parents to
    E9 That Hatched December 31st 2016. These Amazing Life has come into this world. Many Wildlife out there, but The American Bald Eagle- is Number 1. I am from Canada and enjoy watching the Cams/Pictures and Comments from People all over the World. Thank you for this site of great work put together.
    Thank you From -Toronto, Ontario, CANADA

  • Excellent post with such useful information and elegant photos!

  • What an awesome article Ron! Thank you, I really learned a lot. I am also blown away at how each image is tack sharp and perfect. I have some very good raptor text books, and your article on eagles blows them away. Thanks again !

  • Judy Eberspaecher

    As usual, Ron, you answered every question that popped into my head and more. Your written details are excellent and if the reader misunderstands, your beautiful images tell it all.
    I hope you don’t mind but again, I am sharing this excellent post with my birding groups in Canada. Around the Southern Ontario area of Canada, Bald Eagles have made a significant comeback and are nesting here. In Nova Scotia on the Atlantic Coast, Bald Eagles have been numerous for many years, even when they were threatened in the U.S.
    I’m sure all the members will appreciate your knowledge and expertise.
    Happy Thanksgiving to you and yours, Ron.
    PS: Right now I am enjoying the birds of Botswana as I spend time in this wonderful part of Africa. Lots of lifers!

    • Judy, Share away! If posts like this make folks appreciate and respect birds even more I’m all for it.

      Your time in Botswana sounds like a dream trip!

      • Patty Chadwick

        When I taught at at the childrens’ rehab. hospital. One of my students was the teenage son an official from Botswana. He’d received a head injury in a car crash. Every time we looked at each other, we’d start laughing…it was crazy! I used to like to rub his nose which was a little lighter in color…(from all the rubbing?). We were good buddies…I miss him….a lot!!!

  • Cat

    Great write-up Ron. I find it very helpful in my eagle watching! Do you think there are many differences in eagles geographically? I live in Central Florida and see many eagles. I’m just wondering if the cycle (plummage, colors, etc), are the same. Thanks!

  • Alice Beckcom

    Ron, I share other’s comments such that this is a beautiful and educational posting. Both the Bald Eagles and the Golden Eagles are spectacular looking birds…very majestic. I hope I get to see either or both of them in my lifetime.

    Thanks for the posting and have a Happy Thanksgiving!!

  • Kim Lopez

    Thank you so much for the magnificent photos and the id lessons. Now I live in Cuernavaca, Mexico, further south from the capital and where we see a completely different variety of song birds and raptors. It is unlikely we will ever see a bald eagle in this region mainly because it is not their range. I have seen bald eagles perched and in flight in the northern part of the country, closer to Texas especially near the Rio Grande. I also recommend Jerry Liguori’s book on raptors from every angle. Also super helpful is the Crossley ID raptor guide that Liguori publishes with Richard Crossley and Brian Sullivan. Greetings!

    • Kim, in my view Jerry’s raptor knowledge is unsurpassed. And I can vouch for the fact that he knows ALL OF IT off the top of his head! He’s amazing to have around anytime but especially when there are raptors around.

  • Laura Culley

    I need to begin with a hearty THANK YOU for all the work you do here. What a joyous way to begin my day (even if the day’s half gone before I get here). Along with your stunningly beautiful images, you almost always take care of that learning-something-new-every-day thing and that almost always saves me a lot of time and effort…LOL! Not today, though. I knew this progression in bald eagles and the difference with goldens. But seriously, THANK YOU! You and Mia are a delightful pleasure!
    And a happy Thanksgiving to everybody!!

  • Marty K

    I’m so glad you updated and ran this post again! MAGNIFICENT* shots of MAGNIFICENT* birds!!!!! (*continue to add favorite superlatives ad infinitum!) 😀

    I’m particularly partial to this post because it was a link to the original from dceaglecam chat that first drew me to your blog a couple of years ago. It was “love at first bird” and I’ve been hooked ever since!

    Happy Thanksgiving to everyone who is celebrating and have a marvelous Thursday tomorrow to all. I am eternally thankful for the beauty of this blog community!

  • I will probably never see either a Golden or a Bald Eagle (of any age) for myself but loved this lesson. And the images.
    Megathanks – and a Happy Thanksgiving to you and yours.

  • Patty Chadwick

    Just have to comment, again…thanks to this posting, I FEEL RICH!!!!

  • Dan Sedenquist

    Very helpful series, Ron. Wish we had more opportunity to see them in our area… They are coming back!

  • Eloise Rivera

    Breathtaking!!! Wonderful lesson!

  • Eloise Rivera

    These images are breathtaking. And very informative. I learned a lot new today.

  • Wow! Tremendous photos! Thanks for going through the different Bald Eagle molts with words and photos; I enjoyed seeing the changes. The last photo is amazing!!!

  • Dick Harlow

    Hey teach, you’ve done it again – given a fantastic lesson, with awesome images, Well Done!
    Living in the east I use two major clues that you outlined! Is the bird near, over or beside water – probably a Bald Eagle, but still need to check field marks..
    Over land either cruising or perched, look at the head and neck area, is it golden, yellow to tawny brown, a Golden Eagle.
    However, I have seen Goldens flying over trees beside a river that empties into a lake, so one needs to be cognizant of the field marks!
    Many thanks for lesson, great post!!

  • Patty Chadwick

    WOW! WOW! WOW! I’m taking this posting “personally”!!! As if it was tsilor-made for me…..PERFECT!!! Love it!!! Thank you!!! Drooling over every, single image…hard to pick a favorite, but one of the golden flying probably is one of them…thanks ,again. HAPPY THANKSGIVING, EVERYONE. I’m especially thankful for getting to “know” all of you, especially you and Mia, Ron.I THANK THE EAGLES FOR THIS!0

  • Charlotte W. Norton

    Awesome informative series Ron!

    Charlotte

  • Betty Sturdevant

    This is a wonderful post. I love the educational aspect of your work as well as the beautiful pictures. I have been to Alaska and seen so many there. They seem as plentiful as sparrows and are very majestic. Wonders of the world.

  • Elmer Deloso

    Another great tutorial & photo series, thank you!

  • Joanne OBrien

    Thanks for the beautiful photographs and educational post!! I learn so much from your blog.

  • Susan Stone

    Very helpful post, though I think one would have to do a lot of study to not be confused by the maturity stages of Bald Eagles. I think they, along with various Gulls have the most complicated plumage changes as they mature. Supposedly we have Goldens at the park, but I have yet to see one. I think I thought I saw some Goldens on Kodiak Island some years ago, but based on what you’ve said in this post, I am now pretty sure they were juvenile Balds.

    • I’ll bet your Kodiak eagles were immature Balds too, Susan. Personally I don’t even try with gulls – they overwhelm me and I have more interests (and challenges) in other groups of birds.

  • Carol Vavra

    Beautiful images, especially of the sub-adults! I also wonder why the mature adults will tolerate a sub-adult around, especially with their own fledglings. I didn’t think they would recognize their offspring from previous years. Wonderful job catching these photos!

    • Carol, it’s not a matter of toleration as much as it is the fact they had no choice. When conditions are right (very cold winter and lots of dead carp concentrated in a relatively small area) eagles have no choice but to feed in close proximity to each other. And there’s many, many fights.

  • Kevin Collie

    Ron – that last image is just spectacular! What a moment you captured there. That’s pretty special.

  • Gail Rich

    Thank you so much for the info and the beautiful photos! Last year my 4 juvenile eagles here in North Florida had a lot of mottling underneath while they were still in the wingersizing stage and couldn’t fly. Is that unusual?

    • Gail, I’m not sure how to answer your question because I’m unsure about what you mean when you say “wingersizing” stage…

      • Gail Rich

        Sorry! Our local Eagle Watch group calls it wingersizing instead of exercising when the eagles hop and flap around in the nest tree, getting ready for their first flight, and first landing! I couldn’t find a way to attach a photo, but during this stage you can see the underside of the wings quite well. In all 4 of the eaglets I watched grow up last year, the underside was very noticeably mottled in appearance at this stage.

        • Ok, now I get it (a little slow on the uptake…).

          No, I don’t think it’s unusual. Here’s what Jerry Liguori has to say about it in his book:

          “Juvenile bald eagles are mostly blackish underneath with white axillaries and varying amounts of white along the underwing coverts and secondaries”.

        • Laura Culley

          At the Cornell Redtail Hawk Nestcam, we called that stage of development flappercizing. And boy was it a challenge to keep up with three baby redtails on the cam, while they were trying out those new wing/feather thingies, figuring out how the controls worked! 🙂

  • Marina schultz

    Beautiful!!! Awsome!!!! And one of my favorite pictures of yours the eagle feeding while flying !!!!!

  • This was really interesting, especially the photos with a few eagles in various stages of development shown together. I had no idea that it took so long for bald eagles to acquire their white heads and tails. One of the things I’ve noticed here in Minnesota the past several years is that bald eagle sightings are not as rare as they were when I was a kid. They are really beautiful creatures.

  • I’m so glad that you published this wonderful series— I hadn’t seen the original version. As there are several pictures which contain 2 stages of immatures with a full adult, i wondered– was
    that happenstance, or do family units stay closely linked for a number of years ?

  • Judy Gusick

    Wonderful photo’s and commentary, Ron! Thx for the lesson on Bald vs. Golden. We do get both here tho I suspect some of what we “think” are Golden are actually immature Bald. I tend to look for a definite white patch on the lower side if the wing for Golden………. Is that a clue or not?

  • Colin McKee

    Awesome and informative post Ron. Great pics and info. I think this may have been the post I found on the net several years ago when I first reached out to you. I sent you a few photos and asked your thoughts on what type of eagle I had captured in some pics southern Ontario. And you let me know it was a juvenile bald something, I had never seen in the wild before or since. Keep up the awesome posts.

  • Great info and beautiful photos.
    Now….if only I can remember all of this.

  • Thanks for the lesson on identity, especially with photos!

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