My First Eagle Census

Yesterday I was reminiscing about the many interesting experiences and opportunities I’ve had since becoming a volunteer for the World Bird Sanctuary.  Foremost among these was the first time I was invited to take part in a Bald Eagle Census in 2003.

Most of us know about the U.S. Census for humans--Did you know about the Bald Eagle census?

The call came on a Saturday morning.  It was our daughter, Teri, Director of Education for World Bird Sanctuary.  She wanted to know if her dad and I would be interested in doing a Bald Eagle count with Jeff Meshach on Tuesday.  Jeff was at that time the Director of Animal Management for WBS, and was and still is in charge of doing the yearly eagle census counts each December through February, when the birds migrate south in search of open hunting waters.

As far as I was concerned this was the opportunity of a lifetime!  Jeff laughingly told Teri that we had called him back within 14 minutes of his original call.  An eagle count consists of four people in a small plane flying at low altitude down (or up) the center of the river channel.  The two people in the rear of the plane are the spotters, and Jeff records the number and type of eagles (adult or juvenile), and their approximate location, on a river map.

As time drew near to the day of the count, the weather forecasts were not sounding promising.  On the morning of the count we showed up at Spirit of St. Louis airport not knowing if we would even be able to take off due to weather conditions – 12-14 degree temperatures with wind chills I don’t even want to think about, and possible snow.  However, our pilot, George Stephenson, assured us that the weather would not be a problem, and that we would be flying well beyond the “no fly zone” created by a Presidential visit that day in South St. Louis.

This would be two adults perched

Jeff gave us a quick rundown on procedures for spotting the eagles.  My husband, Art, and I were each to count the eagles spotted on our respective sides of the plane.  As we spied the birds we were to call out the number and type of birds and where they were located, i.e., “2 juvies perched” (which means perched in trees), or “3 adults on the ice”.  Jeff then recorded this information as it was called out.

This would be two adults and one juvie on the ice

At one point, action on my husband’s side of the plane was a bit slow and he began to count birds on my side.  Apparently we gave Jeff and George quite a chuckle when I told my hubby to mind his own side of the plane.

These numbers are given to several Bald Eagle population monitoring groups, who then use them in conjunction with numbers supplied by other spotters around the country to guage the health of the bald eagle population.

Census counts are just one of the many tools in World Bird Sanctuary’s arsenal to ensure that our grandchildren and great grandchildren will still be able to see our country’s national symbol in the wild, and not just in cages at zoos.  We hope that future generations will never have to say to their children, “Once upon a time there used to be a bird called a Bald Eagle….”

Submitted by Gay Schroer, World Bird Sanctuary Volunteer/Photographer

Bald Eagle Census

Last Thursday, I participated in a survey of wild Bald Eagles along the Mississippi River.  

We departed from the Spirit of St. Louis Airport in Chesterfield in a Cessna 185 named the “Earth Angel.”  The plane was beautifully painted red and white, but the interior of the plane was significantly smaller than most cars.  We wore headphones to communicate over the hum of the plane’s engine.

The familiar landmarks in Chesterfield Valley seemed like pieces on a model train town as we flew overhead.  When we reached the Alton lock and dam on the Mississippi River, we began to count the Bald Eagles we observed below.  

Bale Eagles perched in trees along the river

Even though the plane flew as slow and low as possible, the eagles still appeared only slightly larger than the head of a pin.  Most of the eagles perched on the branches of large cottonwood trees growing on the very edge of the river.  We observed a few eagles in flight.  I was most amazed to spot eagles perched on ice blocks floating in the river.  They balanced on the edges of the ice and peered over into the water, waiting for an unlucky fish to swim past.  This sight reminded me how well eagles and other birds are protected from the cold temperatures by their feathers and the scales on their feet.

Bald Eagles perched on ice floes use another hunting technique 

As we spotted the Bald Eagles, Jeff Meshach, the Assistant Director of WBS and navigator of this flight, marked their location on a detailed map of the area.  We also noted whether the bird was a juvenile or adult, and whether it was perched, flying or standing on the ice.  In all, we counted 676 bald eagles.  The majority were adults perched in trees and were most heavily concentrated in the northern sections of our survey area.  Happily, the number of bald eagles in the survey has increased significantly over all the censuses done last year.

Submitted by Leah Sainz, World Bird Sanctuary Naturalist

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