How long does the bald eagle live?
A. Typically in the wild probably between 20-30 years. Some eagles in captivity
have lived up to 50 years, but in the wild they would not live as long.
How do you determine a bald eagle's age?
A. By plumage until they are 5 years old, then after that you cannot age
Does the bald eagle mate with different kinds of eagles?
Do bald eagles have only one mate for life?
A. Typically, yes, although occasionally an intruding adult (not one of the
pair) comes in (usually a female) and battles the resident bird for the
territory, sometimes then taking over. If one of the pair dies, the other
will find a new mate and usually keep going in the same territory.
Do eagles push their young out of the nest to encourage
them to fly?
A: No! The adults may withhold food as the eaglets get near fledging, and
encourage them to fly to a nearby perch to get their meal, but that's
about it. Usually, no coaxing is necessary and the eaglets are all too
anxious to test their wings!
Q. If an eaglet falls, will a parent fly below the
nest to catch it and carry it back to
Do bald eagles build their nests
in low trees?
A. No, nor do they prefer to. Given the option, eagles will choose a "super-canopy"
(one rising above the rest) tree with sturdy limbs and a commanding view
of the surrounding terrain, which is also always very near to water. Typical
nest heights are 50-125 feet high.
How tall do trees have to be for a Bald Eagle to nest in?
A. The higher the better!
Why do bald eagles have such big nests if they only have two eggs?
A. They are large birds and their young become quite large, demanding of
lots of space to fit all the birds and their 6 foot plus wings.
About how long does it take for the bald eagle's eggs to hatch and how
long until it can fly?
A. It takes 35 days to hatch. The young remain in the nest for another 10-12 weeks until they fledge (fly from the nest.)
How old are they before young eagles can fly?
A. At 10-12 weeks, when they leave their nest.
When do eagles learn to fly and how?
A. At between 10-12 weeks as they first leave the nest (fledge), and then
with more and more practice to and from the nest and surrounding trees
over the next month or two.
How old does a baby have to be to leave its mother?
A. 10-12 weeks to leave the nest, although fledglings then often stay around
"learning from their parents and honing their flying and feeding
skills for another 1-2 months.
How long does it take the eaglet's feathers to turn brown?
A. 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
How do eagles find their old nest?
A. 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 - 100 miles in a winter day in search
Out of twenty eaglets, how many will live to be adults?
A. This varies with the population in question. From our work releasing eagles
in New York, about 2.5 adults would survive for every 20 (1 in 8). Mortality
is highest for eagles in their first year of life, especially their first
six months. The first winter is crucial. Some biologists (two studies)
have estimated mortality as high as 72 % within one year of fledging (leaving
the nest). Another study estimated that only 11 % of eagles were alive
after 3 years of life. In general, we believe that only about 1 in 10
eagles survive to adulthood (5 yrs of age).
Q. How many eggs does an average bald eagle lay in
A. The average bald eagle clutch size is just under 2 eggs/clutch
(1.9). 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. So 2 eggs/year X 20 years = 40 eggs in her
Q. Why are eagle nests so large for
their body size?
A. 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!), because most
pairs add sticks to the same nest each year, and use them for many years.
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.
Q: What does the female eagle do when she gets
older? I heard that she plucks all of her feathers out and she makes
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. So, yes, I believe paired adults do
it as a "courting"/bonding activity. 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.
How long can an eagle live? How long do they usually live?
A: That depends on what might happen to it! Unfortunately, many
eagles don't live out the length of the life they are biologically capable
of, due to a variety of factors. Contaminants, shooting, traps, cars,
trains, wires (electrocution), collisions, and even other eagles, can
cut an eagle's life short. Barring any of these events, an eagle is capable
of living for 30 or more years. We captured an eagle in 2001 that we had
banded in 1976, a female who was still breeding. Eagles held in captivity
undoubtedly live longer than those in the wild, since they don't have
the stresses that eagles in the wild face (such as finding food everyday
and defending their territory. Two reports exist of captive eagles living
How long do the young stay with their parents after fledgling?
A: Depends on how "independent" they feel! Some youngsters "bust-out"
quickly, thinking they are fully capable of being on their own. In many
cases, they pay for this with their lives during their first fall and
winter. On average, I'd say they spend 4-12 weeks in the nesting territory
post-fledging, the time during which they learn to hunt and fly.
Do young eagles learn to hunt from their parents or are their skills innate
A: An excellent question. Young eagles from wild nests develop their hunting
skills on their own, but spend considerable time after they fledge watching
their parents and undoubtedly learning by watching what the adults do.
The actual skills involved are learned by trial and error, I'm sure. Much
of the hunting skill (or at least the drive to hunt) is innate, as our
hacked eagles were fledged into an environment without adults around to
"teach" or "show" these young birds. Yet, these birds,
again through trial and error, learned to hunt for themselves and survive.
We felt it was important to continue to provide food at our hacking towers
after the eaglets fledged, to give them a source of food for as long as
they needed it. Eventually, each eagle at it's own pace, these young birds
stopped using our offerings and began foraging on their own. Similarly
in the wild, the adult parents will continue to provide food for some
time after fledging, while the newly flighted birds hone not only their
hunting skills, but there flying skills. On average, I would say it takes
about 4-12 weeks for young eagles to start hunting successfully. True,
fully refined, specialized hunting skills, probably take years to develop.
In the wild, how long can Bald Eagles bare young?
A: The life span of eagles in the wild is generally around 30 years.
Actually, little is known about the reproductive life of eagles as they
age, due to the lack of known-age/banded birds and intensive observations
of same. I can tell you that we captured one of our local breeders at
her age 25 years, and she went on to breed and raise young successfully
in her 26th year. It is my opinion that eagles are probably productive
until they die. It would be mal-adaptive for adult eagles to remain in
the population as non-contributing members. More often, I believe what
happens is the aging/unproductive bird is actually killed and replaced
by a younger, more productive and fit adult.
We know that dog life spans are 7 years to 1 human's life span, so what
is the eagle's life span to a human's span?
A: To answer that we have to explain how long eagles can live.
In captivity (a more coddled life...), bald eagles have lived well into
their 40's. But in the wild, their life is undoubtedly much shorter, either
cut short by human beings, by other eagles, or by the rigors of their
life. In the wild, we believe eagles live around 30 years. Therefore, I guess
you'd say an eagles life is about 2.5 to each human year, based on our
current average life expectancy.
Q. What is the average lifetime of a bald eagle?
A. Most of what we know about how long eagles live is from birds
kept in captivity. These birds may live 40 years or longer. Information
from a few wild, banded eagles shows that they may live to be 30 or a
little older in the wild. I suspect that a 25 year-old bald eagle in the
wild is old, and a 30 year old eagle is very old.
Do the golden eagle babies look different from the bald eagle babies?
A: Yet another great question from Ferrisburg!
Yes, golden eaglets look different than bald eaglets. When first hatched
and as young nestlings (before feather growth starting at about 4 wks
of age), golden eaglets are mostly white. Bald eaglets are much darker
gray. Also, golden eaglets have a very noticeable yellow "cere"
at the base of their bills, all through their nestling stage. Bald eagles
do not; balds are uniformly dark. As golden eaglets age, they maintain
a much lighter, whiter head than bald eagle nestlings. As they age they
attain their very distinctive "golden" nape from which their
name derives and which is the most obvious difference in older age eaglets.
Check out some photos of both on the net and see for yourself!
We had a pair of eagles with a nest in a large tree near the Missouri
river near Nebraska City. This winter the tree went down and we're worried
that the pair won't nest here again. We've seen an eagle on the ponds
nearby standing on the ice eating something. Will "our" eagles
still nest here or will they move on?
A: Sorry to hear "your" nest tree blew down; a not uncommon occurrence!
Not to worry. Eagles are very faithful to their nesting "territory",
not necessarily to the actual "tree". I don't know how long
the eagles have been nesting there, but I would fully expect them to build
a new nest not too far away. This could be up to a mile, rarely further,
but I'd suspect even closer, all other conditions (like food) being equal.
Watch for them carrying sticks off in a certain direction.
Q. How long do eagles stay on nesting grounds after
they migrate in spring?
A. It all depends on what latitude they breed at. Eagles migrating
to and breeding at northern latitudes (i.e., Yukon Territory) probably
stay a shorter period of time, and have a shorter nesting season than
those at southern latitudes (i.e., California). That is because of the
shorter season in the northern areas. The water stays frozen later into
the spring, and fall comes earlier there.
If they are going to nest successfully, there
a few things eagles have to do wherever they nest:
or refurbish their nest (may take only a day, but we'll say 1 week,
eggs (35 days),
- Raise young to independence (perhaps 120 days).
these numbers up comes out to 162 days or a minimum of about 5 1/2 months
on the breeding area. More
typically, in temperate areas such as Washington state, the adults will
remain on their territories at least 9 months of the year before fall
Q: Could it be possible that a twig
I saw an eagle break from a branch could be used for building a nest? After observing a bald eagle perched in a tree along a river for
over 20 minutes, I observed it fly to a tree 10 yards away and break off
a branch in its talons and fly off. This occurred in Iowa in early February.
Two eagles have been seen in this area throughout the winter.
A: Absolutely it could! I assume the eagle you observed was an
adult. Immatures may occasionally do this for play or practice, but it
is typical behavior for adults prior to and during nesting. What you saw
could be a local breeder getting its nest "ready" for the breeding
season (here in NY we have some pairs who begin decorating their nests
in early February, and I'd bet Iowa would too), or, it could have been
a wintering bird just fooling around and "feeling its oats"
in anticipation for migration and nesting back up north. Very rarely,
some wintering birds will actually build a nest on their wintering grounds
during the winter season, even though they have no intention of staying
and using it (they just might be very stimulated breeders!); we have seen
this in NY, and the pair return to their "winter" nest and decorate
it and sit in it each winter, before leaving for their "real"
nest somewhere up north in late March. The fascinating thing to me about
what you describe, and which I've also seen, is how the heck the eagle
"knows" that the stick they fly at and hit in mid-flight will
give way! It's got to be a good decision between flying force at the stick
to break it off versus not sort of flying yourself into a brick wall so-to-speak!
How do they know ahead of time the stick they've "chosen" will
break off ?? (that's a rhetorical question, not a challenge one!). Anyway,
that is a neat thing to observe! I would look for a nest in the vicinity!
Do they reach a point like humans where
they cannot bear young?
For 3 years I have observed a nesting pair of Bald Eagles near my home.
The pair has been nesting for 15 years in the same location. Last year the male crushed one egg in mid air. The other made it to a
first flight only, never to be seen after a few days. It stayed in a tree
near the nest, but then died. The pair is currently nesting. She laid the eggs on 2/28.
A: I'm curious to know where you live! Judging by the February 28th egg
date, you must be in PA or south NJ? The mid-air egg-crushing you mention is quite strange and begs another
question. Did this pair raise/fledge any young the same year? I think,
you are saying one young was fledged.
Often, one of the adults will remove egg-shells from the nest after hatching;
could you simply have seen egg-shells being "cleaned" out of
the nest and dropped? Adults will also sometimes remove whole eggs that
don't hatch, fly from the nest with them and drop them (they will also
simply eat them in the nest). I have never heard of anyone witnessing
"crushing" of an egg in mid-air. Perhaps it was one of these
normal behaviors you witnessed. I have no idea what could have happened
to the fledgling. Again, after fledging, juveniles will often perch along
the shore away from the nest for a long time, in hard to observe places.
Were both adults present at the nest the whole season?
New York State Dept. Environmental
Division of Fish, Wildlife and Marine Resources