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 as well.

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.

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.

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 maturity.

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.

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.