Hi Anita
Due to the care needed for an open wound, maybe 2 weeks at least depending on size and cause, along with the need for continuous antibiotics, pain medication and follow-up blood tests to insure no auxiliary infection, and the cygnet’s young age, it is highly unlikely that you will be able to return the cygnet in a timely manner. The younger the cygnet and the longer the time separated from the parents (more than 2-3 hours), the less likely parent swans will take him back. Nature wires the parents to care for their existing cygnets and family and not waste time on a cygnet that disappears or is sick/injured. The parents will also recognize something is wrong with the cygnet and he eventually can’t keep up with the rest of the family. The injured cygnet will be shunned, chased and stressed. You will need to find a good waterfowl sanctuary or a good safe enclosed private home for him. The Regal Swan