WASHINGTON, Feb. 25 (UPI) -- An Arizona-based non-profit organization has joined the search for information about 13 bald eagles found dead in Maryland, bringing the total reward in the case up to $25,000.
The Center for Biological Diversity's offer of up to $15,000 joins pledges from the Humane Society of the United States, the Humane Society Wildlife Land Trust, Phoenix Wildlife Center Inc. and the U.S. Fish and Wildlife Service.
The rewards were offered for information about what caused the deaths of four bald eagles discovered Feb. 20 in a field near Federalsburg, Md. Another nine bald eagles were found dead nearby.
"These 13 bald eagles deserved better than to be killed," said Catherine Kilduff, a staff attorney at the Center, in a statement. "Bald eagles have been a remarkable story of national conservation and recovery over the past 40 years, but clearly there's more work to be done. If they were poisoned or shot, the heartbreaking deaths of these 13 bald eagles is a crime. Those responsible need to be caught and prosecuted."
Officials suspect the animals may have been poisoned, either by ingesting poison made for rodents, eating rodents that may have consumed poison or by coming in contact with chemicals sprayed onto a field.
Of the 13 dead birds, at least three were considered mature. The carcasses were sent to the National Fish and Wildlife Forensics laboratory in Ashland, Ore., for analysis. Finding a cause for the deaths could take several weeks.
Although bald eagles are no longer on an endangered species list, they remain a protected species and killing one remains against the law.