Photo by Ketzirah Lesser & Art Drauglis

Thirteen bald eagles were found dead on Maryland’s Eastern Shore over the weekend, and now groups are willing to shell out a total of $25,000 for answers.

The Center for Biological Diversity initially pledged $15,000 for information leading to an arrest and conviction. Then, the Humane Society of the United States, the Humane Society Wildlife Land Trust, the Phoenix Wildlife Center Inc. and the U.S. Fish and Wildlife Service, kicked in $10,000 for a total reward of $25,000.

Officials suspect the birds may have been poisoned, and an investigation is underway.

“These 13 bald eagles deserved better than to be killed,” said Catherine Kilduff, a staff attorney at the Center in a release. “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.”

Bald eagles were taken off the endangered species list in 2007. Regardless, suspects could face civil penalties, criminal penalties, or prison time for violations.

Maryland hasn’t seen this many deaths of eagles at once in more than 30 years.

Anyone with information may contact the U.S. Fish and Wildlife Service, Office of Law Enforcement in Cambridge, Maryland, at 410-228-2476, or the Maryland Natural Resources Police Hotline at 800-628-9944.