Eagle Behaviors - Care at Developmental States
Care of Eagle Eggs
Bald eagle eggs often do not hatch in the wild. There are many
different accidents which can befall an egg in the wild. So, in order
to care for eggs for recovery purposes, special precautions must be
taken to avoid the dangers which exist in the wild and man-made threats
For example, in the wild, bald eagle parents must incubate the
egg for a full 35 days. During this time, the egg must remain at a
steady temperature of 99.5 degrees Fahrenheit. If the incubating parent
is frightened away from the nest or leaves the nest even very briefly,
the egg may become too cold or too hot, depending on the weather. Also
during this period, the eagle parents continuously turn the egg with
their feet. The turning process prevents the embryo from sticking to
the inside of the egg shell. Occasionally the egg is dropped from the
nest during this process and it cannot be recovered.
Personnel involved in recovery efforts attempt to imitate
nature placing, bald eagle eggs in incubators set at 99.5 degrees
Fahrenheit. Then, recovery personnel or special incubator equipment
turn or rotate the egg. Eggs are kept in a sterile environment and are
only handled with gloves to reduce the possibility of bacterial
infection when the eagle begins to hatch. Another incubation method
borrows from nature. Rather than use machines, a particular breed of
chicken, the black bantim cohin, may be placed on the eggs to incubate
them as its own eagle parents would. Since these hens lay eggs of a
similar size and weight and care for their eggs in the way eagle
parents do, they make good substitute parents.
If eagle eggs need to be transported during the process of egg borrowing or egg fostering,
they must be carefully placed in cardboard tubes lined with styrofoam.
The egg must sit securely in the foam to prevent jarring that might
crack the eggs. Of course, this transportation process must take place
quickly to ensure that the egg remains at the appropriate temperature
and rotates on schedule.
Care of Bald Eagle Chicks
Bald eagle chicks
also require special care. The most critical aspect of caring for
chicks is preventing the chick from imprinting on the humans who are
caring for it. When the bald eagle chick first hatches, it is unable to
focus its eyes for nine days. During this time, recovery personnel feed
the chicks shredded food (such as quail meat or fish) with tweezers.
The chicks are never handled and talking is avoided as well. Latex
gloves and a military style camoflouge attire which covers the entire
body, including the face, is worn by recovery staff even though the
chicks will not be able to see clearly for a few days.
Bald eagle chicks begin competing for food with their siblings
(brothers or sisters) almost immediately. In the wild, these
competitions often lead to the death of the smallest chicks. In the
care of recovery staff, young bald eagles are separated and placed in
separate plastic or metal tubs to prevent fratricide.
Chicks continue to receive food from camoflouged staff after
the first nine days, but then the chicks are fed with a lifelike
plastic adult eagle head puppet. This enables the chicks to imprint on
the food source, which closely resembles an adult bald eagle. Feeding
with the puppet continues until the chicks are about six weeks old and
are taken to a hacking tower or other enclosure.
Care of Juvenile Eagles
Once the bald eagle
reaches six weeks of age, it can be moved to the site where it will be
released. Usually this is a hacking tower. A hacking tower is a large
cage where young eaglets are kept until they are ready to fledge or
take their first flight.
The cage is built high above the ground (at least twenty-five feet)
like an eagle's nest. Typically two or three sides of the cage have
metal slats to allow the eaglets to become familiar with the site. It
should be located near a large body of water and the tower windows
should permit the eagle to see the food source (the water) and also
possible nesting areas. The cage should be large, a minimum of 8' x 8'
x 8' to allow the eaglets to flap their wings and exercise in
preparation for flight. Feeding and water mechanisms which allow humans
to feed the eaglets without being seen or heard are necessary. For
research purposes and to ensure the safety of the eaglets, a one-way
observation mirror is usually a feature of a hacking tower. The tower
is generally located in an area where the bald eagle population is low
because the tendency is for the young eagle to return to the place of
its first flight to nest to begin raising a family when it reaches
The hacking tower is designed to offer all the features of a
bald eagle nest. Therefore, a man-made nest of sticks lined with soft
scrap materials sits in the middle of the tower. The eaglets sleep in
the nest, but are free to move about the tower. It is very important
for the eaglets to be protected from any form of human contact.
At about twelve weeks of age, the young eaglets may be
released. Recovery staff look for signs that the eaglets are ready to
fledge. Signs include wing flapping and increased activity and
movements toward the open sides of the tower.
Finally, the side of the hacking tower facing the water is
lifted. Eaglets may take from 15 to 45 minutes (on average) to leave
the tower. Perch poles attached to both release sides allow the eaglets
to make a short flight before taking off. Once the eaglet has left the
tower, it will continue to return to the tower for a few weeks to
receive support and food. Eventually the young bald eagle leaves and
begins a nomadic lifestyle which does not end until it reaches sexual
maturity, chooses a mate, and begins to nest. At that time the bald
eagle will return to the area where it first fledged or to the fledge
site of its mate.
Care of Adult Eagles
Adult bald eagles
avoid human contact whenever possible. However, if a bald eagle is
injured, it may require care. Bald eagles that have lived in the wild
may be rehabilitated and released again when they have recovered from
their injuries. In such cases, after receiving medical attention the
eagle will stay in a rehabilitation enclosure that includes a flight
area. Some enclosures are equipped with large pools into which live
fish or other prey are put to allow the eagles to practice their
hunting skills during their rehabilitation.
The care of adult bald eagles differs from the care young
receive because of the danger posed by their predatory physical
adaptations: talons and beaks. An adult bald eagle's talons are capable
of exerting 1,000 pounds of pressure - enough not only to pierce
through the entire arm but to break a human arm.