Mississippi River bald eagle communities appear to be crashing

For over 60 years bald eagle communities have been coming south during the winter to find food and shelter near the dams and power plants along the Upper Mississippi River. They have been coming down from upper Michigan, Wisconsin, Minnesota and Canada where they had nested the previous summer.

Some bald eagle communities would spend the winter along the river, feeding below the dams. Other bald eagle communities would find what they needed to survive, inland away from the river. Each of these inland communities would have a feeding area of up to 250 square miles, which is the area within eight miles of the community nighttime roost. Even some of the river communities of bald eagles would fly up to eight miles to get to a sheltered valley, so they could be out of the wind during the cold, stormy nights.

During the height of the bald eagle recovery in the 1980s, each of these communities could have 40 to 60 birds. When a bald eagle community migrated, the birds that were migrating may stop for a few days to feed within another community's area, if there was plenty of food. So during migration certain dams with available food could be flooded with eagles, host to as many as 10 other communities for a few days as the birds tried to fill up before they moved north or south. This resulted in many eagles being sighted near certain dams before the communities moved on.

During the late 80s and since, many of the bald eagle communities which wintered away from the river either died out or moved elsewhere. First the percentage of young in the community declined, until only adults were left, and then the adults would disappear as well. This whole decline took anywhere from 10 to 15 years.

Since 2000, the communities along the river have started to follow this same trend.

The trend is easy to overlook when simply counting the number of birds in an area, since a declining wintering community may be supplemented by other bald eagle communities moving through going either north or south. But it is clear the eagle population is not as great as it used to be.

This is the 55th year the Eagle Nature Foundation has conducted the Annual Midwinter Bald Eagle Count. The count is conducted by hundreds of volunteers from Minnesota to Tennessee during the same two-hour period and it has documented the overall decline in the percentage of immature eagles over the past 10 years. This follows the pattern of decline as it occurred in the many inland communities that have disappeared.

Many cities along the Mississippi started Bald Eagle celebrations to draw people's attention to the many bald eagles, which at one time, were wintering in their own areas. How many of these celebrations during the past few years have had few, if any, bald eagles flying free? To offset this, many communities now bring in live captive or injured, bald eagles for people to see.

This year, it appears that every community of bald eagles along the Mississippi all the way down to St. Louis has declined or disappeared entirely. Not only is the percentage of young declining, but the total numbers of bald eagles are declining. Even the nests are not being used. It appears that only about 10 percent of the known nest sites along the Mississippi are active for the 2015 season.

We must find the reason for these declines, and sooner rather than later. The cause appears to be a chemical poisoning, just like DDT was in the 1960s. If it is, we need to find out what it is, and stop its use.

Could the crash be being caused by a chemical like glyphosate, the chemical in Roundup, which is killing our honeybees and Monarch Butterflies and is working its way through our food chain? Or could it be neonicotinoids, which have been banned in Europe? Whatever the cause, it seems the birds are being affected during the winter, as the total number of immatures and adults is much lower by the end of each winter than it was at the beginning.

Where we used to be able to see 600 to 800 bald eagles, now we only see 20 to 30. I don't know what to call this decrease other than a crash.

' Terrence Ingram is the executive director of the Eagle Nature Foundation and has been researching bald eagles wintering along the Mississippi River for over 50 years. Comments: (815) 594-2306.

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