There were three families of mute swans nested in the area but only one family fortunately survive because of "mute swan management", Mute Swan is considered an invasive species in Ontario,Canada.Local government think it risks to native wildlife and thus using a lot of non-human solution such as oiling the eggs or by removing eggs from nests to control its population increment. I really do not know whether " management" is good or bad. however,As an immigrant, I am at least as as invasive and and non-native as mute swans in Canada.