Normally, a cob will stay with one pen for life (usually) and this is why everyone looks to the swan as a symbol of fidelity. However, this fidelity is dependant upon the individual bird, the successfulness of mating and rearing young and the individual species. There is a possibility that he only has one mate as female swans will lay eggs during the nesting season. So, one clutch of eggs may actually be infertile. It will be interesting to see if both clutches have viable young.

As for the coloring of the eggs, we have also noticed that some are greenish/blue, white and brownish. The coloring has a lot to do with age and contact with sunlight as the older the eggs or more sunlight, the darker they become. The Regal Swan