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

• The exotic mute swan has increased its population size in Chesapeake Bay to approximately 4,500 since 1962.
• In 1962, five mute swans escaped from an estate in Talbot County, Maryland.
• More than four decades later, their descendants had grown to nearly 4,000 in the Chesapeake Bay region.