CHICKS The chick will be fed a steady diet of fish, occasionally
supplemented by waterfowl (ducks, geese) or waterbirds (gulls, cormorants).
About 85% of the chicks diet will consist of fish. Fish like carp,
white sucker, shad, bullhead and sunfish are most frequently caught.
The adults will tear the fish into small strips and offer it to
the chick. The chick will snatch it from the adult's beak and swallow
it. The chick will eat as much as it can at a feeding, storing food
in its crop. The crop will appear distended (enlarged) as it fills,
resembling a golf ball at the base of the neck.
HUNTING & FEEDING The male does most of the hunting and scavenging
during the early weeks of the chick's life. The female does the
majority of the feeding and brooding. The male will often eat the
head of the fish he catches and then bring the remainder to the
nest. The male will brood and feed the chick when the female is
off the nest. She will leave to stretch, defecate, bathe, preen
and hunt on her own.
THE ADULTS The male eagle is smaller than the female. He weighs
about 10 lbs. and the female tips the scales at about 14 lbs. Being
smaller, he is slightly quicker and more agile, giving him an advantage
in catching prey. She, being larger, is better able to incubate
the eggs and brood the young chick, using her body to shelter her
offspring from cold, soaking rains or hot sun. The male's wingspan
is a little more than 6 feet from wingtip to wingtip, the female's
is between 6.5 and 7 feet.
CHICK'S GROWTH The chicks will be nearly full grown at 9 weeks
of age. They will add some weight as they develop their flight muscles
after they leave the nest. Their wingspan will be as large or slightly
larger than the adults at this time.
FIRST FLIGHT First flights usually occur at 9 or 10 weeks
of age. They are proceeded by vigorous exercising and flapping.
The chick will typically lift off of the nest by facing into the
prevailing winds and flapping. Often its first flight will be only
to the nearest branch above the nest. When they leave the nest they
usually glide to a nearby tree or stump. They will return to the
nest tree frequently and continue to be fed by the adults.
CHICKS LEAVING THE NEST As the chicks develop their flight
skills they harass the adults and try to take fish from them. This
behavior will last into September. As of October, the bond between
the adults and their young will fade and the adults will no longer
tolerate the harassment from their offspring. This is time when
the young eagles leave the territory, usually heading north in the
early fall to find good fishing grounds.
MIGRATION Eagles don't migrate in the sense that robins and
bluebirds do. Eagles only travel as far as they have to in order
to find food. This is particularly true of adults with established
territories. Adults will stay on their territory (roughly 1 - 6
square miles) tyear round, as long as there is open water nearby
when they can hunt fish and waterfowl. Should a severe winter limit
the food supply, eagles will move as far south as necessary to find
open water and suitable hunting grounds.
YOUTH TO ADULT The young eagle will spend the next 4 years
of its life wandering across eastern North America looking for summering
and wintering areas where food is accessible. The mortality rate
for eagles during their first year of life is greater than 50%,
but once they have learned to hunt and forage successfully their
chances of reaching adulthood are good. When they begin to mature
at age 4, the eagle will seek a mate and establish a territory.
The territory is usually located within 250 miles of the nest where
the eagle was hatched. There, the new pair of eagles will construct
their own nest but often don't produce eggs or young during their
first year as a pair. They'll return in following years to raise
young of their own.
DISTANCE TRAVELED Immature eagles wander great distances
in search of food. Birds banded in Massachusetts have been sighted
as far away as West Virginia and southern Canada. Eagles sighted
in Massachusetts have come from as far away as Maine, New York,
New Jersey, Pennsylvania, Connecticut, New Hampshire and Michigan.
These facts were provided by the Massachusetts
Division of Fisheries and Wildlife.
