We have 2 mute swans and they recently had 5 eggs hatch. The large pond they are on is full of turtles who have snatched the cygnets in the past years. Can we pen them up on land and what might be considered the safe amount of time for their best chance of survival? Do we pen them alone or with momma swan? Do they have to access to the pond and how often? We are feeding the cracked corn and pellets and they have a large swimming tub. Thank you.