Identification Series: Eagles

• by Kiah Jasper

As people who have birded with me likely know, I am always looking up. When everyone else is looking for warblers and thrushes in the undergrowth, I am trying to peak through gaps in the canopy for migrating raptors and other species found in the sky. It is probably no surprise then that it was raptors that got me interested in birding, the sighting of two Golden Eagles near my home leading me to discover the birding community. I spent countless hours of my teenage years lying atop my parents van in the front yard, waiting for eagles, hawks, and falcons to migrate overhead. I later moved on from the van, visiting most of the well known hawk watching sites across the province (including Holiday Beach, where I spent the 2024 fall season and part of 2025 as the official hawk counter). It is because of this love of raptors that I wanted to write this post about two birds that I am very familiar with. I hope the tips below can help you sort out some birds in the future.

Introduction to the problem

Is that a Bald? Or perhaps a Golden?? These two species frequently start ID discussions all across Ontario, especially during “eagle fever season” in the fall, when the first sightings of Golden Eagles turn up across the province in early October. Before we get too into the weeds about this ID, I’ll explain a bit about why these two species are some of the most frequently confused in our region. First off, you have the Bald Eagle, a ubiquitous raptor found in every county of Ontario and a species that has undergone a massive population increase in the last several decades. The appearance of an adult Bald Eagle is recognizable to birders and non-birders alike, a white head and tail and a dark body. Bald eagles take 4 to 5 years to reach this distinct adult plumage though, before then they go through many different appearances over the course of their immature years. It is these young balds that are often the ones to cause confusion among birders, because, unlike the adults, they lack the characteristic white head and tail and instead sport various shades of brown. The colouration of the body and wings of immature Bald Eagles are also incredibly variable, from mainly white with dark patches, to mainly dark with light speckling, and seemingly everything in between.

Then you have the Golden Eagle, the much more uncommon one out of the pair and a prized species among birders in Ontario. This species breeds in remote areas far to the north of most Ontarians, from northern Quebec and across the Hudson Bay region in Ontario. Birders in the southern part of the province have the chance to encounter these majestic birds each year as they migrate to and from their wintering grounds, passing through southern Ontario mainly during October and November in the fall, and March and April in the spring. Small numbers of goldens do spend the winter months in Ontario, especially in key wintering areas of Southwestern Ontario such as Middlesex, Grey, Bruce and Simcoe Counties. That said, for most birders it will be a bird encountered during migration.

Golden Eagles also take 4 to 5 years to reach full adult plumage, though unlike Bald Eagles their plumage is fairly similar in all age classes, with varying shades of brown, grey and black dominating their plumage. The immatures differ from the adults mainly in their tail and wing colouration, which show varying amounts of white. The head of a Golden Eagle, featuring a dark throat and a vibrant “golden” nape, is shown by all age groups. Because goldens are such a sought after species by birders (the case with many large, showy raptors, including owls, Gyrfalcons and American Goshawks), immature Bald Eagles can cause a lot of excitement because, at a glance, they can show many of the characteristics birders typically look for in a Golden Eagle.

Brief Note on Terminology

Before I get too far into the weeds, I wanted to go over some of the terminology used in this article. You don't have to have an understanding of all the feather tracts on a bird, but for this pair of species, knowing some of the basics helps a lot for describing a bird!

• Flight feathers - The long feathers on the trailing edge of the wing used for flight. The two feather tracts that make up the flight feathers are the primaries and secondaries.

• Primaries - The 10 flight feathers at the end of the wing.

• Secondaries - The 14-15 flight feathers that go from the base of the primaries to the body of the bird.

• Underwing Coverts - The feather tracts underneath the wing that are used to protect the base of flight feathers and the arm.

• Undertail Coverts - The feathers on the underside of the tail that are used to protect the tail feathers.

• Terminal Band - A band at the end of the tail

You will also notice that I say immature for the majority of non-adult eagles, with some specific age classes in brackets, for example "Immature Bald Eagle (Second Year)". Immature is a blanket term used for any bird that isn't an adult, while juvenile refers to only a bird's first plumage after it fledges (this plumage is retained for about one year for eagles). So all juveniles are immatures, but not the other way around. Make sense? Additionally the majority of Bald Eagles can be reliably aged by examining their underwings, however Golden Eagles are often much more difficult, requiring a view of their upperside (which hard to come by). So in this article almost all of the Bald Eagles will have a bracket noting what year they are, while Golden Eagles are left simply as "Immature". Now on to the ID!

Breaking down the identification

Let's start tackling this ID by discussing something obvious that birders often consider first when identifying a bird, the plumage. When it can be readily observed (if the bird is close enough and isn’t completely backlit), there are some helpful plumage differences between the two eagle species that can be very useful when trying to identify them.

1) – Head Colour

Bald Eagles have all white heads as adults, so if you see the bird well there’s no real confusion there. When they are in their immature plumages though, their heads can appear to be almost completely dark, light brown or a patchy mix of brown and white… sometimes they even have a large white “eyebrow” and other interesting patterns. Goldens are less variable, and while they can have some individual variation, almost all show very similar head colouration and pattern. The classic Golden Eagle head pattern features a brown head and throat, and a contrasting golden nape. In the photos below note that the Golden Eagle has a much smaller bill compared to the Bald Eagles.

1. Left to right; Golden Eagle (adult), Bald Eagle (adult), immature Bald Eagle (second year)

2) – Location of white on the wings

Both Golden Eagles and Bald Eagles have white in their underwings when they are immatures, while adults of both species have all dark underwings. The key to separating the young eagles is the location and pattern of the white. Bald Eagles show incredible variation, with some having mostly white underwings with dark patches, and others showing almost the opposite. The white on Bald Eagles underwings is normally spread out across the whole wing, with extensive white on the underwing coverts. Many individuals also show a lot of white in the “armpit”, where the wing connects to the body of the bird. By comparison Golden Eagles are much less variable, while many individuals show different amounts of white than one another, the white on their underwings is usually restricted to the bases of the outer secondaries and primaries (the flight feathers). This white is usually in very defined patches (I think some birds look like they have white “lightning bolts” on their wings), nowhere near as messy as Bald Eagles. Goldens have totally dark underwing coverts (remember bald has extensive white here), and dark feathers in the armpit at the base of the body.

2. Top left - adult Bald Eagle; Bottom left - immature Bald Eagle (second year); Top right - adult Golden Eagle; Bottom right - immature Golden Eagle.

3) - Tail colour and pattern

Another helpful feature for separating the two eagles is the colour and pattern shown on the tail. Immature Golden Eagles have a contrasting tail with a white base and a black band on the end (referred to as a terminal band). Even at extreme distances this is very visible when the birds are circling and have their tails fanned. Even in an overhead glide this black and white pattern is often noticeable. Adult goldens lack the white band, instead showing a dark brown tail, often with neat grey barring and brownish-orange undertail coverts (the feathers at the base of the tail behind the feet). Immature Bald Eagles are once again, incredibly variable. Their tails can be mostly dark, mostly white or a mix. Note though that they don't show as stark of a cutoff line like goldens do... there is often a dark base and a dark tip to the tail, with white splotches in between. The base of the tail can be dark, and the tip white. Especially older birds (3rd-4th year) typically show more white in the tail, with black restricted to near the base. I encourage you to browse some photos on eBird (click here) to see some of the variability of young Bald Eagles. You will see that a fairly common pattern is a light coloured "bar" across the middle of the tail, with a dark tip and a dark base.

3. Top and bottom left - immature Bald Eagles (second years); Top and bottom right - immature Golden Eagles

Now lets move away from plumage and discuss some other helpful (and unhelpful!) clues for ID.

1) - Proportions and size

One of the things I frequently hear from birders after they saw an eagle was “it had to be a golden! It was huge!” and “there’s no way this was a bald, it was massive!”. They are right of course, eagles are truly enormous birds, something you especially notice if you ever get the chance to see one up close. Size, however, is not a good way to separate golden vs bald. On average Bald Eagles are 86cm (34”) tall, with a 203cm (80”) wingspan, while Goldens average 80cm (31”) tall and have a wingspan of 201cm (79”). Like most other raptor species, females are considerably larger than males, so a female golden would likely be larger than a male bald, but on average Bald Eagles are slightly bigger. Size can be quite deceiving to judge on a distant, flying bird, so because they are so close, this is not a helpful way to distinguish the two species.

That said, there are differences in proportions of some parts of the bird’s bodies that can be readily observed and can be very helpful for telling them apart. The main one is the head. Bald Eagles have large heads and thick, heavy bills, while Golden Eagles have much smaller heads and bills proportionately. Goldens do have large heads and bills compared to most other raptors, they are nowhere near as monstrous as a Bald Eagle. Check out the following two silhouettes, can you guess which is which?

Quiz Bird 1

Quiz Bird 2 - Answers at the bottom of the article!

2) - Impression

When identifying raptors in flight, the impression that a bird gives can often be a helpful initial clue to identify it. What do I mean by impression? Picture a flying Turkey Vulture, teetering back and forth on seemingly unstable wings held in a dihedral (upwards V shape), slowly rising on a thermal. Even if the bird is several kilometers away, it’s distinct way of flying makes it recognizable as a Turkey Vulture, even though no plumage features were observed. Of course that was a very obvious example, and many other birds are not so distinct.

The flight impression of a Golden Eagle is more similar to Rough-legged Hawk or Turkey Vulture than Bald Eagle, something that many people find surprising when they first learn it. To start, Golden Eagles usually soar with their wings held upwards in a dihedral, something Bald Eagles very rarely do. When viewing very distant birds, a banking Golden Eagle will often reveal a bold white tail with a black band (a feature shown by immature Golden Eagles, but not adults) and a flash of golden colouration on their nape (shown by all ages). Rough-legged Hawks also soar with a dihedral, have a black and white tail and a light brown nape (at least in most plumages). Granted, Rough-legged Hawks have much thinner wings and a smaller body, but at a large distance the similarity is there. Turkey Vultures also fly with a dihedral, and during migration Golden Eagles, sometimes stealthily pass over with large groups of vultures. The structure of a Golden Eagle is quite difference from a Turkey Vulture, but if you aren’t paying close attention an eagle could easily slip by with a group of vulture – especially adults that have all dark flight feathers and tails.

When they are flapping their wings or in a powered flight, Golden Eagles seem labored, but more sleek and fluid than Bald Eagles. Bald Eagles also have a much deeper wingbeat than Goldens, appearing stiffer. In a glide Golden Eagles have slightly bowed wings, sometimes held in a slight dihedral. Not an ID feature, but gliding goldens can be very sneaky for such a large bird, sometimes I only notice them when they are almost directly overhead, high above me.

Two immature Golden Eagles soaring, with wings held in a dihedral. Also note the prominent white patches on the flight feathers, the white tails with black terminal bands and the golden napes.

Examples and discussion

Now that we have gone over the basics of eagle identification, lets look at some photos and go over them.

This Bald Eagle is a second year bird photographed in March (hatched the previous spring). Birds like this individual with a lot of retained juvenile plumage usually pose the largest identification issues with Golden Eagles due to their dark plumage. Note that there is still significant white in the underwing coverts, especially close to the body. Also note the large head and massive bill.

This immature Golden Eagle has considerably more white than is typical for the species. The white extends all the way from the outer primaries almost to the base of the secondaries near the body. Note though that the underwing coverts and still completely dark. Also note the white tail with the defined black terminal band, and the small head with a (barely visible due to photo quality) golden nape.

This Golden Eagle is an adult, the much more uncommon age class to see in Ontario during migration. The underwings are completely dark except for a few light specks caused by wing molt, and the tail is totally dark as well. The underwing coverts are a darker colour than the flight feathers, giving the wings a very crisp aand neat appearance. There is a hint of a golden nape visible on a small head. Note how the tail projection is very long.

This Bald Eagle is in its fourth year, showing a mainly white head and mostly yellow bill. The wings are mainly dark, but still have a lot of white in the underwing coverts. The belly also shows considerable white on it.

This Golden Eagle is high up and in a glide, often how they are observed during migration. Note the long tail with white near the base, limited white restricted to the flight feathers, and a small head and bill.

Quiz Bird 1 from the silhouettes above - Golden Eagle. Note the small head and bill, and long tail. Also this bird has an all dark body and underwing coverts, with white restricted to the flight feathers.

Quiz Bird 2 from the silhouettes above - Bald Eagle (second year). Note the large head, heavily bill. Note the splotchy white belly and white underwing coverts. This bird shows a mostly white tail with a dark terminal band, similar to a Golden Eagle. Note that it's only a white band though, and the white does not go to the base of the tail. Some balds such as this one cause a lot of confusion due to their tail pattern, however it is almost always messy and less defined (black bleeding into the white, white splotches on the black, etc) than a golden.

Here is another Bald Eagle (third year during March) that shows a tail with a dark tip and white in the middle. Note that is is a bit "messy", with dark splotches coming into the white, and also the tail base is dark. Golden's tails are more defined and crisp. This Bald Eagle shows extensive white on the body and underwings, which immediately rules out Golden Eagle without even considering the tail.

Takeaway

I hope this short article was helpful! I recommend following this up by going to eBird and scrolling through some photos of both species. Building up familiarity with the variation of appearance is a great way to create a image in your mind of what both species should look like. With good views, remember, the white on Golden Eagles wings is restricted to the flight feathers, the white on the wings of Bald Eagles can be across the entire wing, with the most white frequently in the underwing coverts. Focus on the head and bill proportions too. Seeing more birds will greatly help your ID skills too. Consider visiting hawk watches during Golden Eagle season in the fall (Oct-Nov), particularly along concentration points such as the North shoreline of Lake Erie and Lake Ontario, and the East shoreline of Lake Huron. North winds and sunny days will lead to higher numbers of migrating raptors.

Feel free to reach out to us via email or social media with any ID requests!

Good Birding,

Kiah