One of the two females will be chosen as the mate for the male and the second female will be the odd swan out. This means that the two mates may show aggression to the point that the odd swan is out will be chased constantly around the pond, nipped at and possibly prevented from entering or exiting the water to eat, preen and bathe. She may be nipped at so much that a serious injury could be caused. All of this chasing and nipping can lead to stress which can lead to an injury or illness and even death if the mates get overly aggressive with her. Now, having said this, the odd swan may learn to avoid the pair and their section of the pond during the mating/nesting season and do just fine. You will be readily able to determine this as soon mating/nesting season begins.

The only sure way of determining the gender of young birds is to submit a feather sample to a certified veterinary DNA Sequencing lab. Before you collect the feathers, you must band or microchip the young birds (if too young the microchips will not stay in place) so that their identity can be matched with the results of the testing. Swans can mate at 2 years of age, but we are not sure if geese follow this same pattern. The Regal Swan