Like a puppy…the one year old has over sized feet and beak. So glad he grew into his features. Lovely and no doubt time consuming series. Thank you, Mia. Hershell, Googling albino Bald Eagle did bring up some images of leucistic eagles so it is possible.
You might want to contact someone from a local bird watching group and see if anyone else has reported it. It would be an awesome bird to see. Mia,Thanks as always for the awesome photos they should be used as great teaching ones as well!
I am blessed to live on a river in Mn and see this in my backyard but no matter how many times I see it I never tire of it. Just beautiful! Stunning and breathtaking. These pix just add to the amazing beauty and enjoyment I get out of watching them.
Seeing your wonderful pictures are a great way to de-stress and enjoy the majesty of these gorgeous Raptors. Thank you for sharing. Thank you very much Marcia, Eagles are one of my favorite subjects to see, observe and photograph.
Thank You for the pics of Eagles at various ages. It was very informative and I will be checking out your other postings. Again, thanks and the info along with the pics was great. Thank you for visting and commenting Judy. Great post! We had been trying to decipher the distinguishing characteristics. Another great series. The age progression is fascinating.
You are fortunate to live in such a bird-rich area. I also like to photograph the various plumages throughout the life cycle. Do you find it easier to get closer to the juveniles? Thank you for the Bald Eagle series. It is often said that eagles win their white crowns as they reach maturity because as soon as they are five years old they will start breeding for the first time, however, some eagles get their white heads a year before that. The all American bird goes through several plumage transitions that makes the bald eagle almost unrecognizable for the first years of its life.
From the moment they are born until they reach full maturity, the bald eagle goes through several molting stages to obtain their whiteheads. A bald eagle spends most of its juvenile years covered from head to toe in dark feathers, anywhere between brown and black. As years go by, with each molt the eaglet comes closer to its definitive color, but before it does, a bald eagle goes through four different plumage stages.
We will talk more about each stage later on, but during these years the head stays mostly brown before reaching maturity, while the rest of the feathers go on the reverse, from dark to light and back to brown again. Just like being brown serves juvenile bald eagles survive and camouflage, the white feather crown on adults can serve as a hunting aid to camouflage amongst the sky, it is also a trait to impose their presence in the presence of other eagles or birds.
As eagles reach their sexual maturity by the time their heads turn white, it is also believed that it is an indicator and attractor to find a mate.
As a fun fact, bald eagles mate for life. Young bald eagles can seem to be a completely different species as their color, structure, and their attitude are very different in their first five years. For starters, juvenile bald eagles are mostly dark colored with some visible white feathers along their bellies but not on their heads.
The feathers are brown as soon as they start to appear, which happens starting at 5 weeks of age; they are pretty well fully feathered by 9 weeks. How do eagles find their old nest? Since the nests are so large, it's probably pretty easy, especially if they haven't gone too far!
I suspect though, that you are asking about birds that migrate long distances to and from their nests. In that case, since eagles are diurnal daytime fliers, we believe they use familiar landmarks to guide them to the general area, and once there, use more familiar and specific cues to find their particular lake and then the nest tree. Such cues as extensive mountain ranges or large water bodies or the coastline might first be used.
These birds obviously "store" great amounts of information or "memory" of the landscapes in their lives, as they easily move 50 - miles in a winter day in search of food. Out of twenty eaglets, how many will live to be adults? This varies with the population in question. From our work releasing eagles in New York, about 2. Mortality is highest for eagles in their first year of life, especially their first six months. The first winter is crucial. In general, we believe that only about 1 in 10 eagles survive to adulthood 5 yrs of age.
How many eggs does an average bald eagle lay in a lifetime? If we assume that a female eagle begins nesting at age 5, and lives until she is 25, she will have 20 years of egg-laying. There is no evidence that a healthy eagle reduces egg-laying as she gets older. Why are eagle nests so large for their body size? Actually, eagles' nests are just about right for their body size.
Most nests are about 6 feet across at the top, and with two adult eagles and one, two, or sometimes three young in the nest, it can get pretty crowded. Especially when you consider that as the nestlings approach fledging age, their wing span is six feet or more, taking up most of the nest.
Nests can get very deep one was recorded in Florida that was 22 feet deep! Q: Do eagles carry their young under any circumstances? There are legends about eagles like carrying their young on top of their wings, but I could not find an answer. One source states that eaglets are NOT carried, that they remain in the nest until they are weeks old and ready for flight.
A: I have heard of this legend many times, and have been told there is some citation in this regard in the bible. However, I have never heard of this, and firmly doubt it. The reality of the biology is, eaglets indeed spend weeks on their nest, do all of their own flight training, and fledge from the nest on their own, gradually gaining strength and honing their flight skills over the next month or two. Q: What does the female eagle do when she gets older? I heard that she plucks all of her feathers out and she makes her beak fall off, then grows another and new feathers, and becomes more beautiful than she was before.
A: That is definitely not true. What is true, is that each year all eagles, regardless of their age or sex, molt lose and replace their feathers, so they do indeed get new, strong ones. It has nothing to do with age. Q: Are eagles courting when they interlock talons and soar through the air?
A: With wildlife, it is often hard to determine reasons behind behaviors we may observe. Talon-grappling and tumbling are frequently observed behaviors; seen between all combinations of eagles.
Meaning, between mated adults, un-paired adults, adult and immatures, immatures with immatures, etc. These are also likely "unions" of any-sex combination of birds. That variety of participants, tells me right away there is no one answer to what this behavior is for, but rather, that it happens for a variety of reasons.
Three come to my mind immediately; pair-bonding, aggression, and play. We also know from observations that these represent very aggressive encounters, where sometimes, one or both of the participants are killed sometimes they cannot "un-lock" and crash to the ground together. The most often I see this, is with and between immatures, and I'm convinced it is both play and learning flight capability.
I do believe that eagles get enjoyment out of certain activities, which could be called play, such as when they chase each other in flight, tumble, roll, etc. As with humans, I think immature bald eagles are more prone to "play" than adult birds, who always seem to have something deliberate to do. Q: How long can an eagle live? After the lining is completed, most pairs will form an egg cup on that surface that is composed of very fine plant material with good insulating qualities.
Q: How big are the eggs? What color? How fragile? A: Eagle eggs are about the size of a baseball. They are white to beige in color with a matte finish. The shell is fairly thick and can take the adult weight, particularly if they are laying on a soft surface like the nest lining. Q: What keeps the adult from breaking the eggs?
A: Adults can break eggs if flustered or startled and they step on them in the wrong way. Typically adults are careful when walking around eggs and position themselves in a way so as not to break them.
When adults are incubating eggs the egg cup is made so that it is mounded around the eggs and takes much of the weight. The lining under the eggs also has some give and this also protects them from breakage.
Q: What keeps the eggs from freezing? A: The egg cup which is made of fine grasses has great insulating qualities. Warmth is provided by the adults but the construction of the nest helps. On warm days with good sun the adults may take breaks from incubating and allow the sun to keep the eggs warm. Q: What is a brood patch? A: A brood patch is an area of bare skin on the abdomen of some birds that becomes highly vascularized during incubation.
Many species lose feathers to clear this area. The increased blood supply to the skin which increases the warmth in this area. The brood patch is placed in direct contact with eggs for more efficient heat transfer.
Q: How long are eggs incubated? A: Male and female eagles can perform all of the jobs related to chick rearing but for most pairs they do have roles. In the early period after hatching the male does the bulk of the hunting providing prey to the brood. The male also stands guard nearby and is responsible for territory and nest defense. During this early period, the female does most of the direct brooding and most of the feeding of chicks.
A: Eagle eggs are quite large and it takes a considerable amount of energy for the female to produce a clutch. This constraint along with space limitation within the female has led to the strategy of serial laying. Many birds have asynchronous laying but synchronous hatching because they delay incubation until the last egg is laid. Development does not begin until the onset of incubation so this delay serves to synchronize the brood.
Eagles typically initiate incubation with the first egg which leads to asynchronous hatching. The reason for this is not clear but it may relate to ambient temperatures at the time of laying. They may not have a choice if they want to keep the eggs viable. Q: How do eagles keep their nests clean? A: Like humans, eagle pairs vary considerably in nest cleanliness.
Some pairs are very messy and others maintain clean nests by removing old prey remains and regularly bringing in fresh nest material. Q: How can a bird so big fly?
0コメント