I have runners not calls, but here is what is in Storey's Guide to Raising Ducks (first edition).
from the table "Suggested Feeding Schedule for Adult Ducks" p 203
size of duck - 2 - 3 pounds
Holding period when birds are not producing (pounds of 12 - 14% protein feed)
0.15 - 0.25 per bird daily
3 Weeks prior to and during laying season (pounds of 16% protein feed)
0.20 - 0.30 per bird daily
How much do calls weigh? A pound and a half? If they weigh 2 pounds, and you have 7, that would be 1.05 pounds per day for the whole group.
I don't think the arithmetic works this way, but if they weigh 1.5 pounds which is 75% of 2 pounds, maybe that would be .8 pounds per day. Times seven days would be 5.6 pounds.
They have a large pen. Are they finding alot of worms, slugs and bugs? Getting treats?
Re-reading your original post, at 14 weeks, maybe they aren't even half a pound yet. I think they are okay. Are they making fertilizer? If you offer them some treats, are they eating them? Things like finely chopped cucumber, or small green peas?
