{"id":11888,"date":"2013-01-27T09:01:33","date_gmt":"2013-01-27T16:01:33","guid":{"rendered":"http:\/\/featheredphotography.com\/blog\/?p=11888"},"modified":"2017-11-26T13:19:20","modified_gmt":"2017-11-26T20:19:20","slug":"a-guide-to-aging-bald-eagles","status":"publish","type":"post","link":"https:\/\/featheredphotography.com\/blog\/2013\/01\/27\/a-guide-to-aging-bald-eagles\/","title":{"rendered":"A Guide To Aging Bald Eagles"},"content":{"rendered":"

As we go into prime “eagle watching” season here in northern Utah I thought it might be timely to present a guide that\u00a0would be helpful in aging Bald Eagles as they progress through the 5-6 year process of\u00a0becoming adults.\u00a0 Many of these younger birds are\u00a0mistakenly identified as Golden Eagles by the general public.<\/p>\n

Eagles that have not reached the adult stage are referred to as immature, juveniles or sub-adults.\u00a0 Plumage stages are highly variable, depending on molt sequence, age and timing so other factors like\u00a0iris and beak color are\u00a0also taken into account when estimating age.\u00a0 Eyes gradually change from dark brown to yellow\u00a0while the\u00a0beak goes from blackish-gray to yellow.<\/p>\n

 <\/p>\n

\"bald-eagle<\/p>\n

\u00a01\/4000, f\/8, ISO 500, 500 f\/4, not baited, set up or called in<\/strong><\/em><\/p>\n

\u00a0The adult Bald Eagle is unmistakable with its distinctive bright white head and tail contrasting with the dark brown body and wings.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/200, f\/6.3, ISO 800, 500 f\/4, 1.4 tc,\u00a0not baited, set up or called in<\/strong><\/em><\/p>\n

But juveniles present very differently than adults, especially in the early stages of development.\u00a0 This very\u00a0young bird is barely fledged and was still hanging around its nest in sw Montana.\u00a0 Notice that the plumage is dark brown throughout, though they may\u00a0have some white or pale mottling at this stage\u00a0–\u00a0especially on the underparts.\u00a0 Both eye and beak are very dark.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/2000, f\/6.3, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

This is a first year bird during winter.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

1\/800, f\/8, ISO 500, 500 f\/4, natural light, not baited, set up or called in<\/p>\n

A side view of the same bird as in the previous image.\u00a0 The warm, early morning light gives it a bit of a golden glow.\u00a0 This stage is often confused with the Golden Eagle (Golden Eagles have feathered lower legs or\u00a0tarsi while Bald Eagles do not).<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/3200, f\/8, ISO 500, 500 f\/4, not baited, set up or called in<\/strong><\/em><\/p>\n

Plumage after the first year becomes increasingly variable.\u00a0 There is more mottling and the beak and cere are becoming less dark.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/1600, f\/6.3, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

\u00a0The\u00a0iris is beginning its transformation to yellow and there’s also some yellow at the base of the beak.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/1250, f\/7.1, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

As plumage stages develop through the second and third years the tail\u00a0becomes whiter with a dark terminal band and more white appears elsewhere.\u00a0 The beak is less dark and as the head becomes lighter generally it leaves a darker “eye stripe”.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/1000, f\/8, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

The eye is becoming more yellow and the eye-stripe quite distinctive.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/1600, f\/8, ISO 500, 500 f\/4, not baited, set up or called in<\/strong><\/em><\/p>\n

The beak becomes more yellow (though not as bright as in the adult).\u00a0 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.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/640, 7.1, ISO 800, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

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.\u00a0 The tail now lacks the dark terminal band and the beak is nearly completely yellow.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/1600, f\/6.3, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

\u00a0This bird is very nearly in full adult plumage.\u00a0 The tail is now bright white but there remains some dark flecking on the head.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald-eagle-3875<\/p>\n

\u00a01\/1250, f\/7.1, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

A fully mature adult.\u00a0\u00a0Both head and tail are now completely white with overall dark brown plumage elsewhere.\u00a0 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).<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/1600, f\/8, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

\u00a0Here you can compare three plumage stages of Bald Eagles\u00a0in one photo.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/800, f\/11, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

\u00a0An adult and a young juvenile.<\/p>\n

 <\/p>\n

 <\/p>\n

\"bald<\/p>\n

\u00a01\/1000, f\/11, ISO 500, 500 f\/4, 1.4 tc, not baited, set up or called in<\/strong><\/em><\/p>\n

An adult on the right, a first year bird on the left and an intermediate\u00a0juvenile in the middle with some interesting mottling.<\/p>\n

If the weather and many other factors cooperate, the month of February often provides some fantastic opportunities\u00a0for eagle watching in northern Utah, especially at some of the wetlands around the Great Salt Lake like Farmington Bay NWR.\u00a0\u00a0 Hopefully some will find this post useful in helping them to appreciate these magnificent birds even more.<\/p>\n

Ron<\/p>\n

Note:\u00a0 It’s possible that the last two images in this series were baited.\u00a0 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.\u00a0 I don’t believe the birds in these two images were baited, but it’s possible…<\/em><\/p>\n

Addendum: In November of 2017 I updated this post to include three additional images, more detailed information on aging Bald Eagles and a guide to distinguishing immature Bald Eagles from Golden Eagles. That updated and improved version of this\u00a0post can be found here<\/a>.<\/strong><\/p>\n

 <\/p>\n

 <\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

As we go into prime “eagle watching” season here in northern Utah I thought it might be timely to present a guide that\u00a0would be helpful in aging Bald Eagles as they progress through the 5-6 year process of\u00a0becoming adults.\u00a0 Many of these younger birds are\u00a0mistakenly 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.\u00a0 Plumage stages are highly variable, depending on molt sequence, age and timing so other factors like\u00a0iris and beak color are\u00a0also taken into account when estimating age.\u00a0 Eyes gradually change from dark brown to yellow\u00a0while the\u00a0beak goes from blackish-gray to yellow.   \u00a01\/4000, f\/8, ISO 500, 500 f\/4, not baited, set up or called in \u00a0The adult Bald Eagle is unmistakable with its distinctive bright white head and tail contrasting with the dark brown body and wings.     \u00a01\/200, f\/6.3, ISO 800, 500 f\/4, 1.4 tc,\u00a0not baited, set up or called in But juveniles present very differently than adults, especially in the early stages of development.\u00a0 This very\u00a0young bird is barely fledged and was still hanging around its nest in sw Montana.\u00a0 Notice that the plumage is dark brown throughout, though they may\u00a0have some white or pale mottling at this stage\u00a0–\u00a0especially on the underparts.\u00a0 Both eye and beak are very dark.     \u00a01\/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,…<\/p>\n

Continue reading<\/span><\/i><\/a> <\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[355,334],"tags":[1182,24,43,1180,399,1176,1179,1181,397,134,153,160,400,768,190,1177,1178,311],"class_list":["post-11888","post","type-post","status-publish","format-standard","hentry","category-bald-eagles","category-birds","tag-1182","tag-adult","tag-bald-eagle","tag-beak-color","tag-blown-eye","tag-eagle-watching","tag-eye-color","tag-eye-stripe","tag-farmington-bay","tag-farmington-bay-wildlife-management-area","tag-golden-eagle","tag-great-salt-lake","tag-haliaeetus-leucocephalus","tag-immature","tag-juvenile","tag-plumage-stages","tag-sub-adult","tag-utah-2"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p1zzJh-35K","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/posts\/11888","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/comments?post=11888"}],"version-history":[{"count":0,"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/posts\/11888\/revisions"}],"wp:attachment":[{"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/media?parent=11888"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/categories?post=11888"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/featheredphotography.com\/blog\/wp-json\/wp\/v2\/tags?post=11888"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}