The Blackneck Swan is the most aquatic of the swans, rarely leaving the water except to eat and nest. Males are larger in size and weight than females, and have a larger knob and tend to be more agressive. They are native to South America, and need to have open water all winter to keep them healthy. Fresh water is essential for keeping blacknecks strong and in breeding condition, making them somewhat uncommon in collections. My blackneck pair has bred already this year, producing 5 strong cygnets. Currently they are intrested in the nesting material once again, so hopefully they will double clutch soon!