Eagles can be difficult to spot
OUR CHANGING SEASONS: Tim Dyson offers tips on what to watch for
Eagles may or may not be encountered if we are simply just out hiking in a area where they are known to occur. Being in an area with a lot of open sky, however, is a good idea. Try lakeshores, open fields, or any exposed spot in areas where eagles can be expected to be found in winter (refer back to Part 1 in the Nov. 9 Examiner for the best local areas).
High-soaring eagles can be quite difficult to spot, so pausing often and frequently looking up, can only increase your chances of seeing one. Another thing that will certainly aid with your search for eagles is if you learn a certain alarm call given by crows when they spot a soaring eagle.
Crows will give a certain call when they spot an eagle. In fact, the number of times I have spotted eagles over the past several years would be a lot lower than it is, had I not learned to search the sky more thoroughly after hearing this special call. It is a series of loud and very sharp notes sounding like “BOK, BOK, BOK, BOK, BOK!” given very quickly, and repeated several times as the crow keeps its eye on the apparently offensive eagle slowly moving across the sky.
Now, suppose you are watching a distant soaring eagle. Is it a Bald Eagle or a Golden Eagle? Over the years, non-birders and/or novice birders will tell me of the time they "saw nine Golden Eagles, and two Bald Eagles perched in trees near a road-killed deer”. Rarely can I convince them that those birds that they believed to be Golden Eagles, were almost without doubt, young Bald Eagles (in this part of the world, at least). It seems, (barring veteran birders), that most people believe that any eagle that does not have a white head and tail, must be a Golden Eagle. This is far from true, and is one of my inspirations for choosing this topic in the first place.
First off, lets determine which eagle species we are looking at. One clue is that the soaring Bald Eagle will hold its wings in a rather flat manner. Golden Eagles will usually soar with a slight dihedral, (wings raised at an angle to be held a little higher than the body).
Additionally, if the silhouette shows the head protruding about the same distance out in front, as the tail does behind, it is almost certain to be a Bald Eagle. The Golden Eagle, however, shows a comparatively smaller head, and longer tail, (and if viewed close enough to see it), has a golden sheen to the feathers of the top of the head on down over the upper part of the neck... hence the name "Golden.”
Let’s have a look at plumages (see picture) to determine what kind of eagles we are seeing and learn to tell the various ages of some.
Distinguishing young Bald Eagles from Golden Eagles can be as simple as noting if there is white, and where it is on each bird we see. The sorting out of the younger ones – those eagles that are four years old or less – can really present some challenges.
Bald Eagles
In the top row is featured five plumage phases of Bald Eagles, and although there will be individual deviation from these examples when viewing soaring eagles in the field, these are quite typical depictions of what you can expect of most you might encounter.
B1: A Bald Eagle in its first year plumage. Its body is generally all dark underneath, but the belly area of most first year birds will appear as a slightly paler brownish than the upper breast. The shorter three innermost primaries, (the ten long feathers making up the outer tip half of the wing) have much whitish towards their outer tips which form a distinct whitish patch. The secondaries, (the long flight feathers of the half of the wing closest to the body), have pale length-wise lines running along most feathers, with pale tips. The trailing edge of the secondary portion of the wing shows a very even and serrated flow, as no molt has yet occurred.
The wing coverts, (small feathers forming the covering of the base of the flight feathers), are in rows of light and dark tones. The tail of a younger Bald Eagle is generally white, but with black edging along the outer portions of each feather, and with a black terminal band across the tip in birds of first, second, and third year plumages. (However, those of third year birds often show far less uniformity, and with much more white appearing in their tails).
B2: The second year Bald Eagle has now completed its first partial molt. Its head and neck is still dark, but the breast and belly are now white and with dark speckling. With wings similar in appearance to B1, some of the secondaries have been replaced during the first partial molt, and those new feathers are noticeably shorter than the retained 1st year feathers. This creates an un-even line along the trailing edge of the secondary portion of the wing. **This can be one of the best points to support the identification of one as "2nd year", along with the lightly spotted white belly. The under-wing pattern of B2 is similar to that of B1.**
B3: Typically, a much darker bird than B1 & B2. The overall appearance of a soaring 3rd year bird as seen from underneath could be described as a "dark eagle with small white spots just about everywhere".
**Many individuals will show a whitish speckling on a dark belly, (quite the opposite arrangement in a typical 2nd year bird).**
B4: The fourth-year plumage and apart from a few bits of white within the dark, and dark within the white, after three molts, the bird has nearly reached maturity.
B5: The adult Bald Eagle will now retain this plumage of dark brown body and wings, with a pure white head and tail, for the rest of its life.
The bill and eye colour of a Bald Eagle will gradually change from dark (1st year) to white-eyed and yellow-billed (adult). However, neither is reliable alone or together, to determine age definitively.
Golden Eagles
The bottom row of birds in the chart shows variations of Golden Eagle plumage.
G1: A Golden Eagle in a typical first year plumage. The overall colour is very dark over the entire body and wing coverts, with large white patches at the base of the primaries and outermost secondaries, and a white tail with a broad black terminal band.
G1b is simply a darker extreme of G1a, but included here since the reduced amount of white in the wings can create the illusion of a sub-adult bird similar to G2.
G2: Many of the white-based flight feathers of a 1st year wing have been replaced through an incomplete moult into 2nd year plumage. (3rd year plumage is similar, and whether a bird is in 2nd or 3rd year plumage has much to do with how rapid the moult of the individual in question has been or not. In other words, it is very difficult in the field to determine without doubt, the exact age of a Golden Eagle in the plumages between the extremes of 1st year and adult.) The otherwise darker, new fight feathers of the wing are now showing thin, gray bands as well. The tail of the 2nd year bird has begun to show a less-abrupt contrast between the white base and black band. Also, note that the first grayish band has now appeared just inside the dark terminal band of the tail.
G3: With just a few slight traces of white now showing in the flight feathers of the wing and much more wavy gray banding of the same feathers, this is a 3rd or 4th year bird, and very near mature. The white in the tail is much more reduced, a second thin gray tail band has appeared, and an overall darkening of the tail is evident.
G4: In its fourth year or older. Having attained a very dark appearance with fine gray banding in the flight feathers of the wing and tail, this is an adult Golden Eagle. Some individuals can be quite dark, and barely display any gray banding in the flight feathers at all.
So there you have it. If you have some spare time on your hands, head on out to Burleigh Falls, Stoney Lake, or even check out the river between Peterborough and Lakefield on some sunny day and try your luck at spotting an eagle or two! And be sure to post your observations and images to Drew Monkman's "Sightings" pages so we can all continue to learn from each other about these magnificent birds!
NOTE: In his absence, Drew has asked me to attach the following on his behalf: Local Climate Change News: As severe weather becomes increasingly common, insurers will have to recover their costs by raising premiums. Eventually, the cost of insurance could become unaffordable for many of us. On Tuesday, November 27, Eric Monkman, of Monkman, Gracie & Johnson Insurance will speak on "How climate change will affect your insurance rates". The talk will take place at Trinity United Church, 360 Reid Street, starting at 7:00 pm. Kate Grierson, an Al Gore-trained climate change communicator, will also provide a brief update on the larger picture of climate change in 2018. A question and answer period will follow the talk.