The black swan is typically a southern hemisphere (Australia) swan, therefore, he is not going to be extremely tolerant of excessive cold. We would suggest you bring him in if the temperature gets below 40 degrees F, especially if it lasts for more than 2-3 days. This may seem an awful long time to have to keep him indoors. However, although his feathers may contain down as other birds, he does not have the thick swan feathers like the Tundra, Trumpeters, Mutes or other North American or Eurasian swans that can tolerate below freezing temperatures. A non-heated barn is much better than constant freezing or near freezing weather. Predators will access ice and will hunt for food ferociously during the winter months when food sources are scarce. Predators (small or medium) that might not go after larger prey in warmer weather or times when food source is readily accessible, may attempt to go after larger prey in winter months. Therefore, swans sitting on ice, on the banks of a pond with no covered fencing are easy prey.

If you fence his nests and he is still able to leave and enter the nests freely, you will need to chain link (so that he can see all around him and see and hear predators) the nests on all three sides with the side closest to the water completely open to the lake so that he can enter and exit freely. However, the fencing will need to be covered at the top so that no predators can climb over and into the nesting area. The bad thing about securing a nest with an open front is that it may allow the swan to leave in the event of a predator, but if the predator can access around the 3 sides and gets inside the pen, the swan may not be able to escape.

The idea of a secured barn or garage (free from chemicals) is a great idea and swan habitat for the winter. Just keep the food in water so that you eliminate pests such as ants and rats as much as possible. Food in water is necessary also because swans need water to swallow their food. During the daytime, when it is warmer outside, you can let him go outside and bring him in late afternoon or just leave him in the barn and spray him with water. He does not need to have a bath every day. So, a good spray indoors during warmer times of the day will be good for him. Just use warm water, not hot water or water from the garden hose. He should do just fine with your care. He may not appreciate your love and support during the winter, but he will at least be alive, free from cold, pneumonia, lack of food and predators