In 1962, five pet mute swans escaped in Maryland; within four decades their descendants neared 4,000 and were eating 10.5 million pounds of Chesapeake Bay grasses a year

Five mute swans escaped from an estate in Maryland in 1962 and their descendants multiplied to nearly 4,000 in the Chesapeake Bay region within four decades. The invasive birds eat large amounts of underwater grasses and have also been linked to the displacem…