Usually, the cygnets are old enough to feed themselves after 24 hours of hatching. The only reason that the parents are around is for protection. So, yes, the male will protect the cygnets and unless you see that he is exhibiting defensive behavior towards them, there is no reason to separate them. It is better for the male swan to teach the cygnets how to be swans, something that you cannot do. Once cygnets are taken from their parents, they will imprint on humans and they can never survive on their own outside a captive setting because they do not learn about predators and predator avoidance/escape. The Regal Swan