Monday, April 2, 2018

Inconvenient Data On Bald Eagles

From:Terrierman  Patrick Burns  December 19, 2016

The National Audubon Society's 117th annual Christmas Bird Count is in full swing.

The annual annual "Christmas Bird Count," is mostly an unscientific "bird feeder" bird count done when those birds which are at greatest risk of decline (i.e. neo-tropical migrants including most grassland birds) are actually down south in Mexico, the Caribbean, and Central and South America.

In short, this is the wrong time of year to count birds that are truly at risk!

That said, the 117-years worth of data collected by the "Christmas Bird Count" does have some use, if for no other reason than to prove that one of the biggest fables told about Bald Eagles is more than a small lie.

What's the fable? Simple: that the Bald Eagles was pushed to the edge of extinction by DDT.
Only one problem:  It's not  true. 
In fact, Bald Eagles were pushed to the edge of extinction by bullets and leg hold traps long before DDT showed up on the scene.
The TRUE story here is a common one in American wildlife: as guns became more accurate, cheaper, and more powerful between 1850 and 1900, game laws did not keep up.

The result was a true wildlife massacre.
We not only shot out all of the buffalo that once grazed on the East Coast, we also shot out all the passenger pigeons, Canada geese, beaver, elk, wolves, deer, mountain lions and yes, eagles, osprey and no small number of hawks.
Eagles, osprey and hawks were also decimated by the use of pole traps -- leghold traps set on the top of poles placed around fishing nets and barn yards. Nothing kills hawks and eagles faster, or more efficiently, than a pole trap.
Native Americans did their fair share of shooting eagles too; it takes a lot of feathers to make a bonnet for the tourist trade, and there was no shortage of bonnets being made and shipped east to museums, collectors, and other wealthy patrons.

The graph above (click here to see full-sized graph) shows Bald Eagle populations as tracked by the National Audubon Society's Christmas Bird Count, which has tracked bird populations in the U.S. since 1900.
As you can see, by 1900 -- more than 40 years before DDT was invented -- Bald Eagle populations were vanishingly low. The same is true for Osprey -- another bird unlikely to be misidentified by a dedicated bird watcher.
Ironically, Bald Eagle populations climbed between 1940 and 1970, when DDT was in full use in the U.S.
The reason for this is fairly simple: the Bald Eagle Protection Act of 1940 made it illegal to shoot Bald Eagles. This protection was further expanded when the Endangered Species Act was passed in 1973.
Left to their own devices, and protected from unregulated shooting and trapping, Bald Eagle populations took flight and have now soared. Today, there are about about 8,000 nesting pairs of Bald Eagles in the Lower Forty-Eight, and the Bald Eagle was de-listed from the Endangered Species Act in 2007 (but still protected).
Another American success story. Add that to the rostrum of success we have achieved through a marriage between hunters and conservationists: the return of the white tail deer, moose, elk, cougar, beaver, Canadian geese, wood ducks, and wolves. .
To be clear:  I am NOT saying that the ban on DDT was not good for birds (it was!), only that the notion that Bald Eagles were specifically driven off the map by DDT is simply not true, and obscures an important story about the value of the Bald Eagle Protection Act of 1940, and the Endangered Species Act of 1973.
It also says something about the National Audubon Society that they have not told this true story about the history of the Bald Eagle and the Christmas Bird Count.

And why have they not told this story?  

I think it's because most of the folks who work for the National Audubon Society do not know much about birds, data, or science.  
This is an organization, headquartered in Manhattan, that produces a pretty magazine, but that it has lost its way and has wrapped itself in a history that is largely a fabrication.

The simple truth is the National Audubon Society was an obstructionist when it came to Condor recovery, it bungled the protection of Hawk Mountain, and it was not a leader in the push to bad DDT and "save" the Bald Eagle.

In fact, the Bald Eagle was in deep trouble long before DDT was invented, and awareness of the impact of DDT on birds was not raised by the National Audubon Society, but by Rachel Carson in the pages of New Yorker magazine.  

National Audubon Society specifically rejected an opportunity to lead the fight to ban DDT, which was why the Environmental Defense Fund was created.  
As for the reintroduction of Peregrine Falcons, here too the National Audubon Society had no role -- that was done by a relatively small group of fanatical falconers and hawkers who spent weeks and months hacking captive and incubator-raised birds back to the wild.  Audubon and the other big environmental organizations had nothing to do with it.
With little success or leadership to show for in its long history, the National Audubon Society has invented two lies:  that the "citizen science" of the Christmas Bird Count yields important data, and that the organization had a leadership role in protecting the Bald Eagle from the ravages of DDT.
In fact, neither story is true, and ironically it is the Bald Eagle Data collected by the Christmas Bird Count that illuminates how little of the other data is useful, and how little DDT had to do with the decline, and near-loss, of the Bald Eagle.

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