Recently one of my ducklings was attacked by an owl and he died. His brother or sister (They're only a few weeks old) seems very depressed. He already has a niacin deficiency but now he has barely gotten up. We did get two more ducks of a different litter (same breed different parents). They're much older, about a year. Is there anything we can do to make him feel better, he's even trying to simulate our other duck' s behavior not that he's gone. Does anyone have any advice for what we should do.