Hunters discovered the dead cranes on Dec. 30. They had died recently and were found "in close proximity" to each other, Tom MacKenzie, a U.S. Fish & Wildlife Service spokesman, said Wednesday.
Foul play is a possibility. Necropsies are expected to be completed in about two weeks, he said.
"When three are found dead in the same area, it's unusual and suspicious," MacKenzie said. "A predator, like a bobcat, would take just one."
He declined to release details of the birds' condition. Fish and Wildlife Service special agents and Georgia Department of Natural Resources rangers are investigating the deaths.
Less than a year old, the cranes had been released with seven other "first year" birds at Necedah National Wildlife Refuge in Wisconsin on Oct. 25 as part of the Direct Autumn Release program, which is an effort to reintroduce the endangered species to the eastern United States, he said.
A group of 11 cranes that an Operation Migration ultralight aircraft led south were released at the same time. In that program, biologists and pilots lead young whooping cranes to Florida for the winter.
The three that died had been banded and equipped with transmitters and had been tracked until recently in Kentucky, MacKenzie said.
"These three birds came down pretty much on their own, following older cranes," he said.
The Calhoun County landowner reported the cranes had been in the area a few weeks before being found dead, MacKenzie said.
Whooping cranes, which mate for life, are the tallest North American bird and generally stand five feet tall. Named for their loud and penetrating unison calls, the cranes live and breed in wetlands, where they feed on crabs, clams, frogs and aquatic plants.
The species is protected by federal and state laws.
"All these birds are important. There are only about 570 birds in existence today and about 400 of them in the wild," MacKenzie said.
Investigators are asking the public for help determining what happened to the cranes, said Rick Lavender, a state Natural Resources spokesman.
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