DDT and other toxins have created several lethal problems for Bald Eagles. The most devastating result was a thinning of the eggshells. The shells would become so thin that they would break when the parents sat on them to keep them warm. The control of the use of DDT has played a major role in the on-going recovery of the Bald Eagle. Unfortunately, the following chemicals are still being dumped into the environment and continue to pose a threat to Bald Eagles, as well as other animals.

PCB can cause sterile eggs, death of young in egg, or adults to ignore proper care of the eggs; its source is from industrial dumping. PCBs were once added to the oil that is used to insulate transformers and it was used in some inks. At levels above 40 ppm (parts per million) PCBs will kill an eagle.

DDE can cause thin eggshells or sterile eggs; it is the what is left of the DDT which was once used widely as a pesticide. DDE is a very stable chemical remains in the environment for a very long time.

Mercury can cause sterile adults; it comes from industrial dumping. Mercury was once used to make mirrors, gauges, and several of other things.

Dioxin can cause deformed young; and it comes from industrial dumping. Dioxin was used in chemical manufacturing of things like audio tapes and CDs.

Other Threats

Even though Bald Eagles and other raptors are primarily fish and carrion eaters, they have been seen as marauders that killed chickens, lambs, and other domestic livestock. As a consequence, large numbers were shot by farmers, ranchers, and others. Most of this large scale shooting was ended when Congress passed the Eagle Protection Act in 1940. An unforeseen affect of the Endangered Species Act is the intentional shooting of Bald Eagles. There are a few private landowners and developers who do not want Bald Eagles on their property. Instead of being thrilled or feeling a responsibility to protect this magnificent bird, they will shoot it or cut down its nest.

Shooting is still one of the most common causes of death among young eagles. Immature eagles are all brown and may look like a large hawk from far away, but most of the shootings happen up close where there can be little doubt as to the size of the bird. And besides, hawks are protected too! Another problem is that young eagles haven’t learned to fear people yet and get into situations where some people with firearms apparently can’t resist shooting at such a large bird. Unfortunately, many of these eagle shootings are done by young people who have not been properly trained by parents or hunters on responsible gun use. Current laws allow for fines up to $10,000 and five years in prison for shooting an eagle.

Richard and Julia Kemp/Survival Anglia from Birds of Prey by Dr. Ian Newton Electrical power lines are another danger for the Bald Eagle in its nesting or wintering habitat. Eagles are electrocuted each year by landing on high voltage wires. "Riley," one of the eagles born April 1994 at Bradford Woods, was found dead in northern Indiana. He had been electrocuted by a power line. Many power companies are constructing new raptor-safe lines or modifying old ones.