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

Eaglets almost five weeks old

We have a few new videos to post in the blog. These videos are also on our BlackwaterRefuge YouTube Channel — see the first three videos on the channel page.

To view the videos below, left-click on the video link to open in Windows Media Player, or right-click the link and choose “Save Link As” to download.

In the March 8 clip posted below, you notice a common sight from this season — the mother eagle digging up grass and putting it over the fish meal and then the eaglets. We’ve noticed the mother eagle covering the chicks more frequently this year, although we’re unsure as to why she’s doing it even now when they’re bigger. But she probably covers them to camouflage the chicks (or the meal) from birds flying over the nest. After this clip ended, the eaglets quicky uncovered themselves again. :-)

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In the clip from March 15, you see the father eagle fly in with a fish during a pause in a rainstorm. The mother takes the fish and starts to feed one of the eaglets, although the eaglet seems to get distracted by something toward the end of the clip and the mother is left holding out the food.

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And in the clip from March 21, you see the parent come in with a meal that appears to be the foot of a bird. The younger eaglet starts to feed, but the older eaglet asserts its dominance by pecking the other chick on the head, and the younger eaglet puts its head down and turns away from the meal. This is how the bullying by the older eaglet worked, although there does appear to be much less bullying in the nest at this time. At the end of this clip, the younger chick sneaks a bite.

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We have some additional video from the nest, but I haven’t had time to edit it, so we’ll save it for another post. But both eaglets seem to be doing well and, as I mentioned earlier, there does appear to be less bullying now that the younger bird is getting bigger.

Also, I wanted to repeat something I mentioned on the cam page — folks have asked about the gender of our chicks. We won’t know that until they are close to fledging. By then they will be almost fully grown and we’ll be able to compare their size (to each other and to their parents) to see what gender they are.

On a slightly different topic, I had someone ask about us setting up a deer cam, but the person didn’t include their email address. We don’t plan on starting a deer cam, but there is a good one currently online in western Pennsylvania. Be forewarned that they have a couple different cam shots, and one of them sometimes has a deer carcass, which is used to attract other animals like foxes and birds. The PA cam is especially interesting at night when the live deer and raccoons can appear in large numbers. During the early morning, the cam often has wild turkeys.

As a reminder in case you missed it, we recently updated the Eagle Cam Gallery. Also, our Eaglet-Naming Contest is open until April 18.

Until next time,
Lisa - webmaster
Contact

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

Eaglets almost one month old

First, I wanted to remind everyone that the Eaglet-Naming Contest is open and you have until April 18 to get your names in for our two eaglets. Much thanks to those who have already submitted their names.

Second, I wanted to briefly mention our osprey action — or lack thereof. We’re a little confused by the lack of nesting action from our migrating ospreys this year. We had heard that action was slow at many local nests, which seemed to indicate that the ospreys may have started their migration late because of the cooler weather. We recently heard from photographer Bob Quinn — who makes frequent visits to Blackwater Refuge — that many of our Refuge nests are light on action at this time. We did see two ospreys on the cam nest Saturday and they brought in a few sticks, but then we’ve seen very little of them, so at this point we’re just in a waiting mode to see what our local ospreys are going to do. Hopefully we’ll eventually get a pair (any pair!) at the Osprey Cam nest.

Speaking of ospreys, many folks might not know that Finland is home to a very large and healthy population of ospreys, and there are two Finnish osprey cams that offer some of the most beautiful views I’ve ever seen on a bird cam. I wanted to point out two recent photos from these cams that offer an interesting look at some non-osprey action in Finland. The first Finnish cam offers a view of a forest behind the nest, and recently there was a raven making itself at home. As you can see, they’re still battling with the last bits of winter in Finland. The second Finnish cam offers a stunning view of the water, and this nest often sees action from white-tailed eagles — a raptor that is a close cousin to our American bald eagle. When visiting these cams, just keep in mind their daylight hours are a bit different than ours.

Talons and Pin Feathers

I know folks have been worried about our younger eaglet, although the youngster seems to be doing rather well the last couple days. The food has been pretty good in the nest, and we’ve seen both chicks getting fed. As I mentioned on the cam page, our younger bird lost the white down on his head a little faster than normal because he was being pecked by the older bird, but the youngster won’t have any lasting damage from this.

The white down on our older eaglet’s head is the last of the bird’s first coat of down (they lose it on their heads last). The eaglets are now dark gray on their bodies because they have their second woolier coat of down, and in addition to this gray coloring you can also see the eaglets’ pin feathers starting to come in on their backs and their wing tips. If you were to see our eaglets up close, this is what they would look like at this stage (note the feather shafts starting to appear on this eaglet’s wing).

We’ll talk more about pin feathers in another post, but in addition to their beginner feathers I also wanted to point out the eaglets’ big yellow talons, which are often visible when the birds are sitting up in the nest or sprawled out in the sun.

The beaks and talons of young bald eaglets grow faster than other parts of their bodies, and by about mid-April, their beaks and talons will be close to adult size. Full-size beaks allow the eaglets to feed themselves and full-size feet allow them to hold on tightly to the nest when they’re moving around during windy weather or when they’re flapping their wings in practice for eventual flight.

The eagle’s talons are comprised of four powerful toes that can break through tough fish skin or animal skin and can hold tight to their prey while carrying it home or to a branch. These talons are similar to the osprey’s in that they both have tiny spicules on the toes (spicules are little bumps that help the raptors hold onto slippery fish). But the osprey has one advantage that the eagle does not have — an opposable toe. One of the osprey’s front toes can rotate backwards so that two toes are holding the fish from the back and two from the front. An eagle can only hold the fish with one back toe (called the hallux). This means an osprey has an easier time holding onto a thrashing fish.

Norfolk Eagle Cam

If you haven’t been watching the Norfolk Eagle Cam, I strongly urge you to check out their live video. They’ve been offering some wonderful close-up shots of the three new eaglets. The Norfolk parents have been providing a huge amount of food to this hungry mob, and both parents have been helping to feed the chicks. Also the other day I saw the male adult feed the female adult a few pieces, which she ate. I had seen this behavior with osprey parents before, but never with eagle parents.

I borrowed a few photos from the Norfolk slide shows because I wanted to point out some interesting action here:

• in the first shot you can see one parent passing food to the other. The Norfolk blog said sometimes the male would pass food to the female who would then feed the food to the chicks
• in the second shot you can see the last eaglet hatching next to its two siblings
• in the third shot is a great close-up of two young bald eaglets. Note the white tip on the eaglets’ beaks — that’s the egg tooth which falls off not long after hatching
• and in the fourth shot you can see the large quantity of food — in fact at least three fish and one bird in this view

We feel especially glad that Norfolk is enjoying such great success this year because if you remember, last year they had only one chick and it developed avian pox. Biologists decided to remove the bird and it was taken to the Wildlife Center of Virginia for treatment, and it remains there at this time.

We’ll try to get the Gallery updated later this week. Also, I’ve been told that some new videotapes from the Eagle Cam are on their way to me, so we should have some new clips to post online soon.

Until next time,
Lisa - webmaster
Contact

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