Not much is known about swans and their hormone levels. In fact, we just completed some testing of various swan species with the University of Tennessee-Knoxville Veterinary School's Comparative Medicine Laboratory. We are just beginning to establish data regarding hormones during and prior to mating. Without the knowledge base regarding sex and mating hormone levels, artificial birth control may or may not work.

There have been some offerings of chemical induced birth control provided by Dr. Bill Sladen (Airlee Center, Warrenton, Virginia). You might want to contact him.

Otherwise, there are several processes that some state wildlife commissions are using to prevent Mute Swans from starting feral populations. These include egg addling, in which the eggs are violently shaken or egg oiling, in which oil is placed over the egg so oxygen is deprived and the embryo does not survive. You would need to research this information to find a contact that might help you with these procedures.

Do not take the eggs, as this may cause the birds to double clutch (meaning a new set of eggs will be produced by the female to replace the lost eggs). This is not good for the female as an incredible amount of energy is lost during egg laying and nesting and this could put the female's health at great risk.

Again, this is a relatively new field in swans and hopefully, our research will lead to much needed data that can answer this question. The Regal Swan