Two bald eagles found along Thurmond Lake were sent to veterinary pathologists to determine if they succumbed to a mysterious brain disorder linked to 26 other eagle deaths.
Vic VanSant, a wildlife biologist with the Georgia Department of Natural Resources, said one eagle was found dead on private land next to the Clarks Hill Wildlife Management Area.
The eagle carried a federal bird band, Mr. VanSant said, meaning wildlife authorities will be able to determine part of its history.
A second bird - too sick to fly and under attack by crows - was found at Hamilton Branch State Park on the lake's South Carolina side. That eagle died within 24 hours, Corps of Engineers ranger Shirley Willard said.
The carcasses were delivered to the Southeastern Cooperative Wildlife Disease Study at the University of Georgia's School of Veterinary Medicine for analysis.
Mr. VanSant said the suspicion is that both eagles succumbed to avian vacuolar myelinopathy, or AVM - an always-fatal condition that affects coots and eagles - and has been detected in smaller numbers of geese and ducks.
The disorder causes spongelike brain lesions that kill affected animals.
The condition is believed to be linked to hydrilla, an aquatic weed that appeared in Thurmond Lake about the same time eagles began dying along its shores.
Affected birds may have wobbly or uncoordinated flight and may crash-land. Eagles might fly into objects such as rock walls. On land, birds are unsteady, walk with wings outstretched and appear "intoxicated." In the water, coots and waterfowl have been observed swimming upside down or trailing a wing or a leg.
Source: National Wildlife Center, Madison, Wis.