Our eaglets are growing rapidly, and it looks like they now have their second coat of darker, heavier down. We also see that the eaglets are able to sit up more and move around a bit. In fact, our younger eaglet moved so much the other day that I got a ton of emails asking if it had left the nest! Fortunately, the eaglet had just moved to the far bottom of the nest (near the trunk of the tree) and out of our view. The eagle parents seem to like perching in that area occasionally, and that may be why the chicks sometimes wander down there as well.

As for the eaglets, we see that they’re more comfortable at being uncovered in the nest. The mother eagle only seems to cover them when it rains or when the temperature is very cool in the early morning or evening. Otherwise, the eaglets are left uncovered, but we suspect one of the parents is sitting in the tree watching them, even if we can’t see them on the cam. Once the eaglets are big enough to be safe from predators, the mother eagle will be able to leave the area for longer periods and possibly do more hunting. We hope that will increase the food supply.

As for the father, we have no idea what he does with his time since we see so little of him. As we noted on Thursday, he did show up on that particular day with a fish or two, which was the most we’ve seen from him in a while. He seems to like spending time perching on the Osprey Cam nest, but other than that, he is only visible for brief periods during the day. We hope he is defending the nest area from intruders or sharing in the eaglet-watching duties.

Cam watchers have asked if this is our same pair from last year. Again, we don’t really think so based on their performance. It’s possible one of the pair died during the off season, and the other mate had to find a new partner. Or it’s possible something happened to both our eagles, and this is a completely new pair. Eagles are normally very loyal to a successful nest (which this one is) so we think if our former pair could have returned, they would have.

It is possible this is a new male, which would account for his lackluster performance. Maybe he’s just inexperienced at the responsibilities necessary for being a father — the main one being bringing in enough food for the eaglets and the mother during these early weeks of nesting. But we can be optimistic and say that at least the eaglets seem to be getting enough food to grow, and we hope as the mother becomes less tied to the nest, she might be able to roam farther in search of food, and that will increase the quantity of fish and fowl that we see.

Big Yellow Talons

One of the most noticeable traits on the eaglets now is their big yellow talons or feet. Beaks and talons grow fastest on young bald eaglets, and by about mid April, their beaks and talons will be close to adult size. Biologists speculate that this helps the eaglets because the full-size beak aids them in feeding themselves and the full-size feet help them hold on tightly to the nest when they’re moving around their home during windy weather or when 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 then hold tight while carrying the prey home. 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.

Something else worth noting about the bald eagle’s feet is that the feathers do not go all the way down the leg (called the tarsus), unlike a golden eagle, which has a fully feathered leg. The reason for the difference is that the bald eagle’s primary diet is fish, whereas the golden eagle’s diet is primarily birds and small mammals. The bald eagle’s lower body often gets wet during fishing, so in order for its legs to dry faster and to reduce drag in the water, the legs, or tarsi, are bare of feathers.

Check out this graphic to learn more about the legs and talons of a bald eagle.

Osprey Update

For those who have been watching our trials and tribulations at the Osprey Cam, this is what we know: the fish in the Blackwater River (which is where most of the Refuge raptors fish) should have plenty of gizzard shad and catfish for our local birds. Also, from what our local experts believe, the owl and eagle that we’ve seen perched on the platform at different times would not likely prevent the ospreys from nesting at the platform.

In the past seven years of our Osprey Cam, whenever an osprey pair showed any intention to nest at the platform, the eagles vanished, so we don’t think a periodic eagle perched there is discouraging them if they really wanted the nest. The Great horned owl can be a predator of osprey chicks, but we’ve been told it is not likely the bird is discouraging the ospreys from nesting at the platform.

In the past, the ospreys have had great success at the Osprey Cam nest up until last year. As our old-timers know, 2007 was the first time in seven years of being online that we did not have chicks at the Osprey Cam nest. An intruder female osprey managed to disrupt the family structure, and our father went missing (possibly tempted by the new female), leaving the resident female on three eggs. She stayed with them as long as she could, but eventually had to get food, and while she was gone, a crow came in and punctured all three, thus ending our season.

When an eagle or osprey couple fail at producing a brood, they will sometimes change nests or partners, so it is possible our pair separated or chose not to nest again at the platform for that reason. Despite this, the Osprey Cam nest is a wonderful nesting location. It’s safe from land predators, it’s high and open (like ospreys prefer), and it’s right in front of the river, so we hope that another pair will take it, since we have a lot of ospreys arriving at the Refuge now for nesting season.

If you’d like to see what’s around the Osprey Cam, check out this web log entry I posted back in 2006. Scroll down the page a bit and you’ll see the 360-degree virtual reality Quicktime movie I put together that allows cam watchers to see what’s around the cam including the Blackwater River and the water impoundment areas that surround the nest. This movie also gives you a good idea as to the beautiful habitat that you can see if you visit our Wildlife Drive at the Refuge.

Eagle Audio

Finally, I did want to point out one more new video at the NCTC Eagle Cam blog. They have sound on their cam, and in the clip on this page you can hear not only the adults calling but also the three growing eaglets and their more developed whistles. It’s really a treat to hear the audio.

We’ll try to update the Gallery soon, and I just received a couple more videotapes from the Eagle Cam, so I’ll try to edit them and post some new YouTube videos within the next few days.

Until next time,

Lisa - webmaster
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Tags:
eagles, wildlife refuge, eagle cam, eaglets, Blackwater Refuge, Maryland

 

This entry was posted on Friday, March 28th, 2008 at 7:42 pm and is filed under Chicks, Blackwater NWR. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.