I have 3 black swan cignets received as gifts. Two are thriving but the third is not developing as well and is very thin. I have them contained in a large area with a 10x10 enclosure for security at night. I feed them cooked rice with canned spinach, fresh greens of different types, scratch and they have natural grasses available. The little one does not seem to be gaining weight nor growing as are the other two. Also they have two pools which they spend a lot of time. I live on a small residentual lake and plan to release them next spring.