Contaminants have a history of affecting Florida's panthers. In July 1989, a four-year old female panther was found dead in Everglades National Park. She was one of only three prime breeding-age females in the area, and concern over her death prompted an investigation. Her tissues were analyzed for pesticides, PCBs, and other manmade contaminants. Toxic levels of mercury, an endocrine disrupter, were listed as the cause of death.
Raccoons are an obvious route of exposure.
In the heart of Florida's citrus belt, where panthers live, DDT and other pesticides pollute many waterways. The aquatic food chain bioaccumulates these contaminants, which reach high concentrations in the fish. Raccoons feed on the fish, and panthers then feed on raccoons. Chemicals from a lifetime of meals get stored in the panthers' body fat. The panthers that eat more raccoons, and not white-tailed deer, have higher levels of contaminants in their bodies.