We have a duck that stands out from the others, not physically but (s)he hangs farther away from the others seemingly antisocial. This isn’t the problem though, it sounds like it’s struggling to breath- or it sounds airy and closed off. Same with its chirps, my other ducks have loud high pitched chirps but this one- same as breathing- chirps very quietly. Again it sounds like it’s throat is closed up when it tries to chirp- airy and/ or very restrained. We call him/her sick and we keep it inside under a lamp with food and water, the breed is Perkins and it is about(less than) 1 month old