WBS BALD EAGLE CENSUS FLIGHT 5 JANUARY 2010

For almost 30 years World Bird Sanctuary eagle counters have flown over a section of the Mississippi River counting all the Bald Eagles we can see.

When we started, back in the early 1980’s, the Bald Eagle was an endangered species.  Back in those days, if we saw 200 Eagles in the 134 miles of river we fly over it was considered a very successful flight.

To help attest to the tremendous comeback the Bald Eagle has made, for the last 5 years if we don’t see at least 1,000 eagles on the same section of Mississippi River we are disappointed.  On almost the same January day in 2009 we set the record of 2,154 for most Bald Eagles seen on our census flight.  To say the least, I was disappointed on 5 January when we saw just 395 eagles.  Does this low number mean the Bald Eagle is starting to slip back toward being an endangered species?

The answer to that question is a resounding NO, at least for now.  Of course we biologists always keep ourselves aware of current trends of populations of most plants and animals in the world.  There are many that are endangered and need the help of humans to provide correct spaces so they can rebuild their populations.  Most plants and animals on endangered species lists are there because of humans, so at the very least we must do all we can do to help save them.

The Bald Eagle was an endangered species because of habitat loss and the pesticide DDT.  This insecticide killed mosquitoes, and it was invented because of all the diseases mosquitoes can transmit to humans.  We thought we had the answer to conquer diseases like Malaria, but DDT had a terrible side affect.  Millions of tons of it was sprayed, especially over swamps and other bodies of water that could harbor mosquitoes and their larvae.  Through a process called biological magnification the pesticide worked its way up through the food chain.  Bald Eagles eat mostly fish, and each fish the eagles ate gave a dose of DDT to the eagles.  DDT affects the way calcium is deposited on the egg as it develops inside female Bald Eagles, and it caused the eggshell to be so thin that the egg couldn’t withstand the bird’s weight, so Mom would crush the eggs just trying to incubate them.  When there are no young eagles to replace the aging and dying adults, you have a problem.  To make a long story short, the problem was found by biologists, DDT was taken off the market in the early 70’s, and our national symbol started its comeback.

     So the question still remains.  Why such a low number of eagles on our latest census flight?  The answer is the weather.  If anyone hasn’t noticed we are having the coldest weather since December 1998 and January 1999.  Since early December the temperature has continued to drop, and with the frigid cold we’ve had over the last 10 days the Mississippi has frozen almost all the way across from Alton, IL to all points upstream.  The bulk of the eagles have had to travel further south to find open water to continue fishing.  Also, Bald Eagles will feed on carrion, or dead animals, which is, by the way, why Ben Franklin thought the Bald Eagle shouldn’t be our national symbol.  Anyway, all animals that die now freeze solid very quickly, so our eagle friends can’t even “stoop” (in Ben’s eyes) to feeding on carrion at this time.

     Don’t let the weather stop your Bald Eagle watching.  The majority of the 395 eagles we saw were just downstream from the locks and dams we fly over.  Even during the coldest weather the turbulent water created by the dams will not freeze, so the dams at Alton, IL, Winfield, MO, Clarksville, MO, Hanibal, MO and Quincy, IL still have eagles for you to see. 

If you want to see Bald and Golden Eagles from just a few feet away you can visit World Bird Sanctuary headquarters in Valley Park, MO.  With permission from the U.S. Fish & Wildlife Service, over the years we have acquired many eagles that have injuries making it impossible for them to live in the wild.  Bald Eagles can take cold weather about as well as any penguin, so you can visit WBS on a sub zero day and envy how comfortable the eagles are without having to wear 3 sweaters, 2 pairs of socks, long underwear, a Goretex jumpsuit, triple insulated boots, a down parka and a furry hat.

Submitted by Jeff Meshach, World Bird Sanctuary Assistant Director