Sixteen weeks seems a little early for Cayugas. My Runners all were laying at around 22 weeks, and they are a smaller breed. The very first egg was at sixteen weeks, four days, but then the rest came on board over the next six weeks.
I think the best thing is to keep them at the proper temperature and humidity in the incubator till they are ready - they seem like they might just not be ready to be up and around yet.
I am not a hatcher, just going by what I have read.
@WVduckchick
ARTic, have you checked in over here...
I would make a couple of visits to the nest with some high calorie nutrition, like sweet corn and peas with a few mealworms. Pick her up if possible to check her body condition - she may have lost some weight.
Go with your instincts - I might let her continue for a few more days, especially...
It is up to them. Some ducks do seem to notice color differences, some don't seem to care (based on my experiences with my now-mixed flock). Mostly, mine don't seem to worry too much about it.
Sure looks like Cayuga to me, and cayugaducklady has them, too. My girl is kind of nonstandard - her feathers aren't in perfect condition yet - but she does have blue shimmers on her wing feathers.