Thirteen bald eagles were found dead at a farm on Maryland's Eastern Shore on Saturday, and federal officials are looking into the case.

Four dead eagles had been noticed by a man looking for antlers that deer had shed, noted Candy Thompson, spokesperson for the Maryland Natural Resources Police, in a Baltimore Sun article.

The investigators were then called to the farm, which lies west of Idylwild Natural Area, an expanse of 3,800 acres.
In searching the grounds, offers located nine more dead eagles, said Thompson in the article.

Maryland officials gave their evidence to U.S. Fish and Wildlife Service investigators. There has been no official statement regarding how the bald eagles died.

Nationwide, bald eagle numbers have steadily increased since the chemical DDT was banned in 1973. The number of nesting pairs rose from 487 in 1963 to 9,789 in 2006. Since then, many states have stopped conducting annual counts of the eagles, because their population levels seem relatively secure. 

Even so, the number one cause of death for bald eagles is humans. The National Wildlife Health Center examined 1,428 individual eagles from 1963 to 1984, concluding that of those 309 casualties (22%) were from gunshot; 329 (23%) were from impact with wires or vehicles; 158 (11%) were from poisoning, according to the Virginia Department of Game and Inland Fisheries website.

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