If the swans were there for only 6 months and they have not successfully bred, then a divorce can occur. It is a human conception that all swan mate for life. In fact, this attribute is dependent upon the individual swan and swan species. A Whooper Swan has a 6% divorce rate. However, possibly not as high, other species can also divorce.

The pair that were placed on the pond by the Council may not have been paired prior to their placement, so they may not have completely bonded, especially if they are a young pair. Only time will tell whether they will re-pair. If they do not, and the one female is consistently harrassed, stress may be the result which can lead to illness or injury. In this case, the odd female may need to be placed on another pond and introduced to a new mate. The Regal Swan