No there is no spray or other deterrent. The best procedure is to enclose the pen and confine both swans. Just ensure that the whole pen area is enclosed so predators cannot climb into the fence. Place plastic poultry fencing on the outside perimeter of the pen from the bottom rail upward to four feet high on the pen. This will prevent the cygnets from accidently leaving the pen and being separated from the parents.

Place a feeder in the pen and ensure that the birds have ample nesting/dry bsnk area to preen and dry the cygnets. Ensure a zero entrance to the bank/nesting area so that the cygnets do not incur leg or foot injuries. Keep the cygnets and parents penned for about 8 weeks. This will allow for the parents to bond, allow the cygnets to grow and mitigate some predation such as from herons and egrets. More importantly, it will allow the hormones to level which is causing the aggressive behavior at this time of the year. Another avenue is to capture the male if he chases you and let him know that he can can be caught if around people. This will usually stop him from getting to close to people. The Regal Swan