The majestic Bald Eagle has one of the most incongruously odd calls, given its size. It reminds me a bit of the funky sound that is referred to as elk “bugling.” Such a high-pitched, surprisingly puny sound from such a massive creature! Give a listen here; scroll down to “typical voice”and try not to laugh. I dare you.
Bald Eagles attain their iconic adult plumage around 4 or 5 years old. Prior to that, they exhibit a variety of confusing plumages of brown and white. Here’s a photo of a young eagle. The photographer of this photo suggests that this bird is 2 1/2 years old. This photo is likely an older eagle, likely a 3rd year bird (often called a “subadult” before it displays the adult plumage), according to the photographer’s blog. And this is just a few of the variations. You can imagine how confusing and challenging identifying subadult Bald Eagles can be! But once they sport the adult plumage—pretty much anyone can identify them.
This past summer (2011), I stopped by a Bald Eagle nest in the Longmont area once a week or so and watched the parents raise 3 lively, healthy, huge nestlings in a huge cottonwood in the middle of a field and across the road from a fish-stocked reservoir. The nestling you can see in the is nearly the size of the adult, so you can get a sense of how large this nest is. In the photo on the left, one nestling is sitting up in the nest and you can make out the head of another one, hunkered down in the nest, just to its right. In the photo on the right, you get a sense of the “lumbering around” the nest that the kids do as they exercise their wings and practice tiny take-offs by jumping up in the air while wildly flapping their wings. It’s amazing that they didn’t knock each other of the nest, with all 3 of them rattling and stomping around up there. (Click on any photo to see a larger version.)
The photo below shows the two parents keeping an eye on things from a branch a short ways away from the nest tree. The male is on the left, clearly showing the typical size difference between male and female raptors (referred to as “gender-dysmorphic size).
Pueblo Reservoir hosts a good number of wintering Bald Eagles each year: Christmas Bird Counts in the last 10 years have averaged 8 Balds during the one-day counts. Every year, before the wintering eagles leave the area, Lake Pueblo State Park holds an Eagle Days celebration. This year (2012), the dates are Friday, Feb. 3 – Sunday, Feb. 5. You can read more about the event here.