Migratory & Resident Bird Species Balances Changing Rapidly In Northern Alabama

[hatrack]

Something is powerfully affecting the birds wintering in northern Alabama, increasing the numbers of many, bringing new species and causing others to dwindle. Scientists don't know whether it's climate change, a recovery from the banned pesticide DDT or some mystery factor.

Since the 1960s, the number of the birds in the reservoirs and refuges in northern Alabama have almost flip-flopped. Almost every species' numbers are either climbing steeply or dwindling. And other birds are appearing for the first time. Pelicans, terns and gulls by the thousands now winter north of Birmingham. "When I was a boy growing up in Decatur, a gull, a pelican - those were all seashore birds," said Keith Hudson, the state's nongame biologist for the northern half of Alabama.

Now, the one-time beach birds spend the winter in the reservoirs of the Tennessee River or at Decatur's Wheeler National Wildlife Refuge. And they are joined by nearly every fish-eating bird or duck found in northern Alabama. Almost all are on the increase during the winter.

On the other end of the food chain, the numbers of tiny seed-eating sparrows also are soaring. The exception is the once-common house sparrow, which is in steep decline at Wheeler. Wildlife biologists don't know why. Nor do they have any idea why robins have multiplied almost by 10. Or why an annual winter bird count at Wheeler finds that Eastern bluebirds have increased from an average of seven in the 1970s to 282 in the past decade.

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http://www.al.com/news/birminghamnews/index.ssf?/base/news/1204535752324950.xml&coll=2