We have 2 Mallards that are 6 weeks old. They are both fully feathered except for a few little patches here and there. We have heavy chickens (4-7lbs) (RIR, SLW, EE) and a large roo, but the ducks are around the same size as our smallest hen (2-3lbs). The have stopped using their heat lamp and the temperature is getting up to the mid 60's during the day, around 45 at night. Also, do Mallards get drake feathers? These two have never been very loud since we got them except at bath time when they would peep their heads off, so I cannot tell if their quacks are changing, or if they are just quiet. Their peeps right now are sort of raspy like drakes, but they are both very docile.