Great question. Inbreeding can and will occur. That is why experienced breeders get several breeding pairs and temporarily mark the cygnets with colored bands. The bands can be removed once the cygnets are sold with records kept regarding the breeding pairs. For instance, you can assign a blue band for your first mating pair, red for the second, etc. You just need to be able to distinguish between parent swans and keep records.

We use microchips in identifying instead of bands for parents because the microchip cannot be removed, lost or impede with the bird's walking or flying (if applicable).

We have seen inbreeding in swans and it seems to be more of a concern in mammals than in birds. However, as limited as the genetic anomalies may be, we have seen anomalies such as leucistic color (not albino but limited color pigment), neurological and orthopedic problems. These problems usually manifest themselves years down the road when cygnets from close parents then produce cygnets and something along their genetic lines appear. The Regal Swan