Trumpeter Swans in Chicago (10 images)

A female trumpeter swan wiggles its beak in the water as her newly hatched cygnet swims nearby at Lincoln Park Zoo in Chicago on June 1, 2008. Trumpeter swans were hunted to near extinction by 1900 and now, thanks to managed breeding and recovery efforts, these swans are thriving again in many parts of the Midwest. (UPI Photo/Brian Kersey)

A female trumpeter swan grooms herself as her newly hatched cygnet swims nearby at Lincoln Park Zoo in Chicago on June 1, 2008. Trumpeter swans were hunted to near extinction by 1900 and now, thanks to managed breeding and recovery efforts, these swans are thriving again in many parts of the Midwest. (UPI Photo/Brian Kersey)

A female trumpeter swan swims with her newly hatched cygnet at Lincoln Park Zoo in Chicago on June 1, 2008. Trumpeter swans were hunted to near extinction by 1900 and now, thanks to managed breeding and recovery efforts, these swans are thriving again in many parts of the Midwest. (UPI Photo/Brian Kersey)

A male trumpeter swan swims with her newly hatched cygnets at Lincoln Park Zoo in Chicago on June 1, 2008. Trumpeter swans were hunted to near extinction by 1900 and now, thanks to managed breeding and recovery efforts, these swans are thriving again in many parts of the Midwest. (UPI Photo/Brian Kersey)