So we got a WHOLE bunch of muscovies this weekend at an auction of which we are keeping several and selling of the rest. My full grown hen is being stubborn and hasn't started laying yet Any how I would like to know about how long it takes for them to grow out? Also to help me age them since the new heard is allllll different ages from days old to ummm bigger. About how old are they when their shoulder feathers start coming in? I will get some pictures later because I want help identifying some colors also. Right now the camera battery is completely dead and is on the charger (note to self - don't leave camera hooked to the computer it drains the battery ) One I have picked out for sure to keep is yellow down with a bit of blue undertone. Its feathers are growing in a pretty silver color.