"Massive bird die-off tied to invasive snails"

FRENCH ISLAND, Wis. — Circling high over Lake Onalaska, two eagles fought over an American coot in one of the eagles’ talons.

The eagle lost its grip, and the coot plunged into the water near Broken Gun Island. It bobbed to the surface but made little effort to escape as the eagles swooped overhead.

“He’s probably sick and they know it. It’s easy pickings around here,” said Calvin Gehri, a biological technician with the U.S. Fish and Wildlife Service’s La Crosse District.

The dying coot would soon join the thousands of dead waterfowl Gehri and other refuge staff have collected along the shores of the Mississippi between Dresbach, Minn., and northern Iowa.

More than 25,000 birds — mostly coots and scaup — have died on the upper Mississippi River since 2002 as a result of eating faucet snails that carry an intestinal parasite, according to federal wildlife officials. From 2005 to 2006, there was a 16-fold increase in bird deaths in pools 8 and 9. Last fall, there were an estimated 5,000 bird deaths in the area between La Crescent, Minn., and MacGregor, Iowa.

Faucet snails are found along the Mississippi between Nelson, Wis., and Fulton, Ill., but the highest concentration of the infected snails is in the La Crosse region. More recently, they’ve been found downriver as well.

Wildlife experts are trying to figure out how to get rid of the snails without affecting native snails. Last year, the FWS tried covering underwater rocks with sand and gravel in an attempt to reduce the snails’ habitat..