As temperatures warmed and the animals dispersed along the Atlantic coast, boat strikes became a leading cause of death last month ... changed the status of the manatee from endangered to ...

In recent years manatee deaths have averaged between 400 and 500 ... in roughly a third of the nearly 600 known fatalities the carcasses were not necropsied so the cause of death was never determined.

Manatees are on the move in Florida, as they begin their seasonal travels to warmer waters ahead of the winter season.