Sunday, April 29, 2012

Bald Eagle: U.S. icon is also a conservation success story

Nations around the globe have their flags that help to give them an identity, a visual rallying point as it were.  They can also have their iconic symbols that can range from buildings to geological formations to plants and animals.  For the United States, it is the bald eagle - a symbol of magnificence and strength.

And as the American expansion rolled across the great nation, the bald eagle, whether deliberately or by accident, was slowly pressured and pushed from one habitat to another until this iconic symbol of one of the most powerful and successful nations on earth was faced with extinction.  Irony abounds.

Chosen as the national bird in 1782 (to the disappointment of statesman Benjamin Franklin who had proposed the turkey), the bald eagle's numbers slowly declined until there were only 417 nesting pairs of eagles in the lower 48 states when the Endangered Species Act was initiated in 1963 (the bald eagle was formally declared endangered under the Act in 1967).  The nation's founding fathers did not have to travel far within the new fledgling states to see a bald eagle, but by the 20th century the birds were typically found only in rugged, remote mountainous areas - further west and north where human populations were scarce as was large scale agriculture.  

Along with large commercial agriculture came the need to control pests and with that came the use of pesticides.  The broad use of DDT contributed to the decline of the bald eagle - as well as many other birds of prey - as the pesticide slowly worked its way up the food chain.  When ingested by bald eagles, it produced weakened eggs and the bird's survival rate plummeted.   

Midwest states, with large population centers and agriculture, were essentially devoid of bald eagles.  The state of Iowa, as an example, did not have a single nest from the early 1900s until the late 70s when one nest was finally sighted.  But now it appears that is all changing.

Iowa's number of nesting pairs numbered around 9,000 in 2006 and they continue to grow.  With the use of DDT discontinued, along with the adoption of other regulatory measures between the United States and Canada, the overall population of bald eagles has continued to rise and it was officially de-listed under the Endangered Species Act in 1997.  Numbers now range over 115,000 in the United States and Canada.

The Iowa Department of Natural Resources carefully monitors the number of nests and nesting pairs, utilizing a program that involves both government officials and volunteers to monitor the nests.  The birds need to be observed but not disturbed in any way, so involved conservation groups and the department keep the exact location of many of the nests under wraps. 

The return of bald eagles to states like Iowa is an example of the overall success nationwide in bringing back the populations of bald eagles back to respectable levels.  It is the iconic symbol of a nation but, more importantly, it is an important member of nature's balanced community and a success story that bears repeating for many animal and plant species from coast to coast. 

Source: The Republic
Source: Wikipedia                     

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