Eaglets nine weeks old

Chesapeake (our older eaglet) and Choptank (our younger bird) have been doing a lot of branching lately, but we hear from the Refuge staff that there are no clear signs of flying yet. Eaglets normally fledge around 9-13 weeks of age, so if they had flown, it would have been a bit early.

Cam watchers have asked about their gender. We’re not sure because it’s been hard to get a good shot of them side by side (the one on the right is about the best we have), but we do think there is a chance that Chesapeake is a female (she looks longer) and Choptank is a male, but again we’re waiting for a good shot of them lying side by side before we can be sure.

Cam watchers have also asked about what will happen to the eaglets when they do finally fledge. Normally the first flight is a short one — maybe to a nearby tree where a parent is perched and then back to the nest. Very often the landing is the most difficult part of the first few flights. Eaglets may know instinctively how to fly, but landing is a skill that must be perfected. If you visit the wonderful site ARKive, you can see an interesting video of a white-tailed eaglet (a close cousin to our American bald eagle) flapping and then taking its first flight. At the end of the clip, we see the eaglet swimming (something bald eagles can do as well). It’s not clear, but perhaps the swimming was necessary because the eaglet accidentally landed in the water. :-)

In the book The Bald Eagle: Haunts and Habits of a Wilderness Monarch (by Jon Gerrard and Gary Bortolotti) the authors witnessed a bald eaglet’s bad landing near Bernard Lake in Saskatchewan, Canada:

“Flapping slowly but strongly, C2 cruised past the nest, banked toward shore, and crashed into the canopy of a tree. We could hear the slapping of wings against branches all the way to the blind. When it was over, C2 was hanging upside down from a limb and holding on with just one foot. From out of nowhere the adult male flew in, calling excitedly, and soon perched on a spruce directly above his clumsy offspring. The adult female took off from the nest, circled above C2, and joined in the chorus of cackles. C2, rather calmly, just hung there, occasionally looking from side to side. After three minutes, C2 released his grasp and crashed to the ground.”

The authors played the good samaritans and retrieved C2, placing him on a rock near the nest. When they returned the next day, he was perched in a smaller tree near his home nest and he sported a bulging crop, showing that the parents had recently fed him and he was fine.

Once our eaglets have fledged and practiced their landings for a while, they’ll soon be as graceful as their parents. But the eaglets (or new fledglings) won’t be independent just yet. Chesapeake and Choptank will come back to the nest occasionally during the weeks that follow, and we’ll likely see them on occasion into the month of July. The parents might meet them at the nest with a meal, or the eaglets might come back to sleep or just to rest for a bit. But eventually we’ll see less and less of them, and that will mean they’re becoming independent young raptors that no longer need a nest. At that point, Blackwater Refuge — and the Chesapeake Bay area — will be their home.

Immature bald eagles do not settle down right away — they won’t even get their adult plumage (white head and tail) until about 4 years of age — so in the meantime they’ll wander around, learning to hunt and having adventures as single eagles. They might even venture to locales up and down the Mid-Atlantic coast before coming back to the Chesapeake Bay area to seek out a mate and a potential nesting site when they’re about 4 or 5 years old.

If you’ve never been to Blackwater National Wildlife Refuge and you wonder what kind of habitat the eagles have to enjoy, here are four photos that offer a nice look at the Refuge. Blackwater NWR is home to one of the largest breeding populations of bald eagles in the United States, so our eaglets are very lucky that this is where they were born and where they can one day return again to raise their own families.

Until next time,
Lisa - webmaster
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Tags:
eagles, wildlife refuge, eagle cam, Blackwater Refuge, Maryland

Eaglets seven weeks old

At this stage, our older eaglet might be only a few weeks from its first flight. Normally eaglets fledge around 9-13 weeks of age, although we expect our younger eaglet won’t fledge until 10 or 11 weeks of age since its development fell a little behind during the bullying period.

Cam watchers have asked if the eaglets can feed themselves at this stage, and we do think they are able to tear up food, although they might have trouble making the first rip in a newly caught fish. In this recent photo we can see one of the eaglets nibbling on some leftovers in the nest. Although it’s possible the eaglets can feed themselves to a certain degree, we have noticed in previous seasons that even when the eaglets can rip off food, they often like to have the parent feed them if the adult is nearby. I guess it’s just easier to have Mom do it!

Branching

Each day our eaglets get a little bigger and a little more independent, and it’s a bit sad to think that in the near future they’ll both be gone from the nest for a good part of each day, flying around the Refuge. But before either eaglet makes that scary first leap, they’ll spend a good bit of time branching. Branching is when the eaglets hop out onto the branches of their nest tree and perch there. This activity helps them develop their perching skills (remember they’ve been sitting in the nest all this time) and also gets them acclimated to maneuvering in and out of their nest and around the tree branches.

Our friend Woody Dawson, who photographs eagles near Susquehanna State Park in Maryland, loaned me this animated GIF (975KB) that he made showing one of his local bald eaglets branching. Notice how the eaglet uses its wings to maneuver its talons along the branch. Once the eaglet is in a secure place on the branch, it can perch there and observe the world around its home nest.

The loblolly pine tree that holds our web camera — and the eaglets’ home — has several branches for the eaglets to choose from. If you look in the bottom left corner of our current Eagle Cam image, you can see a branch that points to the left; in past years we’ve seen eaglets use that limb for branching, so it’s likely this year’s eaglets will use it as well.

We did see a photo from Monday where only one eaglet was clearly visible in the nest. We’re not absolutely positive, but we could speculate that during this time the older eaglet might have been engaged in some brief branching. We’ll continue to keep an eye out for photos showing either of the eaglets standing on that branch or jumping from the branch back into the nest.

In our next blog post, we’ll have some new video clips of our eaglets. And as a reminder, we’ll be announcing the winner(s) of our Eaglet-Naming Contest around the end of the week. Thanks again to all those who took the time to send in their names.

Until next time,
Lisa - webmaster
Contact

Tags:
eagles, wildlife refuge, eagle cam, Blackwater Refuge, Maryland

Eaglets six weeks old

Our eaglets are doing very well and quickly growing their dark brown feathers, which will eventually give them the ability to fly. Normally eaglets fledge between 9-13 weeks of age, with younger birds fledging in the latter part of that range.

A full-grown eagle has over 7000 feathers on its body and has a wingspan of 6-7 feet (upwards of 8 feet on the larger female). The eagle’s large wingspan means it must use a great deal of energy to flap its wings. Consequently bald eagles don’t do that much flapping but instead spend a great deal of their time soaring, which requires about a 20th the power needed for flapping.

Eagles soar or glide when they migrate, and also when they hunt and fish. Using thermals and updrafts, an eagle can soar continuously for hours while using little energy. Eagles can fly to an altitude of about 10,000 feet and during normal level flight reach a speed of 30-35 mph.

Like all birds, eagles have very light bones; in fact most of their bones are hollow and contain only air. If you added up the total weight of their bones, it would be about half the total weight of their feathers.

As I mentioned in a previous post, our two eaglets currently have blood feathers (or pin feathers) on their bodies. These blood feathers have a shaft that encases the growing feather and feeds it blood (hence the name). Once the feather grows and unfurls, the shaft will fall off or the eaglet will pull it off. Eventually the blood feathers will lead to a full coat of feathers.

Eagles have several types of feathers to aid them in flight, including the primary and secondary wing feathers, tail feathers, and coverts.

The ten outer primary feathers are on the end of the wing; these feathers are stiff and narrow because they meet the air first and must provide wind resistance. These outer primaries are also notched and they can open like fingers, which can help a flying eagle to achieve lift and drag.

The inner primaries and secondary feathers are flatter and will overlap to provide a smooth lifting surface.

Body, plume and downy feathers are needed for body covering, streamlining, waterproofing, and temperature regulation.

This graphic shows you individual samples of several different types of feathers for both the adult and immature bald eagle.

Lately we’ve been seeing photos that show our eaglets exercising their wings for eventual flight: 1) younger eaglet flapping and 2) older eaglet flapping. In a photo from Tuesday, our older eaglet opened its wings up wide, and we got a good look at its impressive wingspan.

If you were to see our older eaglet up close at this stage, it would look something like this young bird. As you can see, our eaglets are going from tiny, fuzzy chicks to large, fierce raptors. All in a matter of weeks!

In the next blog post, we’ll provide some new Eagle Cam video clips. And as a final reminder, our Eaglet-Naming Contest will end April 18.

Until next time,
Lisa - webmaster
Contact

Tags:
eagles, wildlife refuge, eagle cam, Blackwater Refuge, Maryland