Bald Eagles and Golden Eagles

While making a comeback from the endangered species list, these beautiful birds of prey have remained symbols of strength and courage.


| July/August 2016



Bald eagle

An adult bald eagle is a resplendent-looking creature.

Photo by Robert Winslow

The eagle is perhaps one of the most iconic and intricately woven symbols associated with the United States of America. Printed on currency and even official documents and forms, the eagle is an enduring image of the strength and independence we associate with this country.

North America is home to two species of eagles: the bald eagle (Haliaeetus leucocephalus) and the golden eagle (Aquila chrysaetos). Both are majestic birds of prey with wingspans that range from 6 to 8 feet, with body lengths varying between 3 and 3-1/2 feet. Females are larger than males in both species, and often have a slightly longer wingspan. Females of either species weigh between 8 and 15 pounds, while males weigh between 6 and 10 pounds. Their size – second only to the California condor – makes them unmistakable in flight compared to the much smaller raptors such as hawks, falcons or owls.

The populations of both the bald and golden eagle have seen dramatic changes since the time of the colonists’ arrival in America. It would be impossible to get an accurate estimate from the time period, but there is some speculation that anywhere from 50,000 to 150,000 breeding pairs lived in the lower 48 states.

The application of DDT (dichloro-diphenyl-trichloroethane) in the U.S. from 1940 to 1950 – used primarily to control malaria, typhus and other human diseases transmitted through insects – caused bald eagle populations to plummet to an all-time low of 487 nesting pairs in 1963.

It was determined that DDT alters the calcium metabolism in female eagles which prevents them from creating a hard shell for their eggs. The thin shells were easily cracked, which led to egg loss in the nest. Bald eagles suffered a higher rate of decline than the golden eagle because fish – which is their primary source of food – built up high levels of DDT in their systems. Golden eagles were less susceptible to the DDT because their main food source is small mammals, which were not subjected to the same high levels of DDT. DDT being a large factor in the eagle’s decline, shooting, trapping, poisoning, and lack of prey also factored into the population decrease for both species.

As early as 1940, the dwindling numbers of eagles compelled Congress to pass the Bald Eagle Protection Act, which outlawed the killing and disturbing of bald eagles as well as possession of eagle parts such as feathers, eggs and nests. The law was modified in 1962 to include golden eagles. Legal protection continued with the Endangered Species Preservation Act of 1966, and later the amendment of 1978 listing the eagle under the Endangered Species Act of 1973. In 1972 in what many feel was the most important regulation in the eagles recovery, DDT was banned for most uses in the United States.





mother earth news fair

MOTHER EARTH NEWS FAIR

Feb. 17-18, 2018
Belton, Texas

More than 150 workshops, great deals from more than 200 exhibitors, off-stage demos, inspirational keynotes, and great food!

LEARN MORE