Bald Eagle Facts
Q&A with Peter Nye in 2009
New York Department of Environmental Conservation


Characteristics

Q: How tall is a bald eagle?

A:
About 30 inches.

Q. Do eagles molt annually, or how frequently do they shed their feathers?
I have seen references that state they do not molt annually. All chicks grow early feathers, which last during their adolescence. They molt into adult plumage after breeding, and according to Coles B H. (Avian Medicine and Surgery. Blackwell Scientific Publications, 1985) large birds in adulthood such as eagles molt bi-annually. Another reference states that all adult birds molt annually, in a gradual process through spring, summer, and fall, while flight feathers are molted only during July, August, and September. This claim is not substantiated. What is the truth?

A. Believe it or not, this is not an easy question to answer; even with all the years and people studying eagles, the molting process is still not precisely understood. Prior to reaching sexual maturity at about age 5, we need to think of molts in terms of different plumages.

Young eagles go through four different plumages until they reach their sexually mature, adult plumage, which would be the fifth plumage type. These are (as described by Clark and Wheeler in Hawks of North America):
Juvenile, White-belly I, White-belly II, and Adult transition plumages.

So, you might think, ok, 5 years to sexual maturity, 5 plumages, one molt per year, right? Not exactly. Molt can be affected by a variety of biological and welfare factors (such as food supply, density of other eagles, and others), and not all molts are always complete molts.

Once they achieve their final “adult” plumage, it is likely that bald eagles molt their flight feathers just about every year, primarily in New York from summer through fall. However, some evidence of molting can be seen at almost any time of the year.
This flight feather molt is not simultaneous; rather, matched flight feathers are generally lost at separate times, so the birds are never left flightless.


Life Cycle

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 12-13 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 10-12 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.


Ecology

Q: Where do bald eagles mostly live?

A.
They live almost exclusively around water (lakes, rivers, ponds, oceans) in North America: all around the U.S., except Hawaii, and throughout most of Canada.

Q: Could there be a family of bald eagles living here in Sauquoit?
On the 22nd of December 2008 my friend and I saw a bald eagle circling overhead in Sauquoit, NY. Christianne White, from Celebrate Urban Birds, Citizen Science Cornell Lab of Ornithology, did confirm the sighting. I was reading your website and it mentions no bald eagles have been raising families in the wild.

A: I’m not sure what you mean by “your website and it mentions no bald eagles have been raising families in the wild;" we have well over 100 bald eagles nesting throughout New York State. There are none that we know of in your immediate area, but it is very possible we don’t know of every single eagle nest out there either! All I can say is, if you or any of your neighbors see adult eagles carrying sticks or food repeatedly into a certain area over the next few months, or if you happen to spot a huge nest, bigger than any nest you’ve ever seen, give us a call right away and we’ll check it out.


Other

Q: Are there artificial nest boxes? What is the success rate of the boxes?
The nest tree of a resident pair of eagles blew down in an ice storm this winter.

A: Usually, when an eagle nest or nest tree comes down, there are plenty of alternate trees available for the pair to simply build a new nest in. And, you’d be amazed how quickly eagles can “throw together” a new nest. I’ve seen some construct a new nest in only two weeks. Very rarely do eagles need a human-made nest or platform built for them. We do this occasionally, but almost always not because the eagles need the help, but rather because we want to keep the eagles nesting in a certain area. If artificial platforms are used within an existing nesting territory, their success is very high. Simply putting a platform in an unoccupied habitat and hoping eagles will find it and begin nesting, is almost never successful.

Q: Is there a bird watching organization I should let know if I have seen a pair of mating bald eagles? I know someone tries to keep track of how many mating pairs there are, and I would like to know if I can help in any way.

A: Contact the New Hampshire Audubon Society or New Hampshire Fish and Wildlife.

Q. Whom should I call if I find an injured bird?

A. You should call your state Wildlife or Conservation Department. Some states list their licensed wildlife rehabilitators on their web sites, as well as their contact numbers. Your local phone book should also list your local Conservation Dept. or Conservation Officer numbers.

Q: Why are some places designated as eagle areas and off-limits to humans?
At Portland Power Plant in PA, there was a boat launch, walking trails, picnic tables, and plans for sports fields. A pair of eagles has eliminated the human portion of this area-half of a lake in NJ is off limits to humans due to an eagle nest. A large portion of Merril Creek, NJ is off limits for an eagle nest.

A: I understand it is difficult to lose some use of very limited areas. But, the fact is, the reason there is such special protection for bald eagles and other endangered species is that for far too long, humans were securely in place at the top of the food chain, and had their way with the planet’s wildlife and environment, leading to the crash of too many species and the loss of too many places, places which if still around today, could well be great human recreation use areas now. Basically, we now have to make up for our past, thoughtless actions.


Peter E. Nye
New York State Dept. Environmental Conservation
Division of Fish, Wildlife and Marine Resources
Albany, NY
Spring, 2009