The big day is supposed to be tomorrow (incubation period is 28 days). I noticed last night that the ducklings are moving around inside the eggs, and one of them had a hairline crack this morning! So that one for sure has broken through the membrane into the air bubble at the large end of the egg -- an essential step. If I listen carefully, I can hear faint peeping from inside the eggs.
I cranked up the humidity just to make it a bit easier for their tender little lungs. The incubator hasn't been cooperating (first the automatic turning mechanism, then the fan, broke down earlier) -- but at least I got the fan working again, for ventilation and temperature control. Pretty neat that the heat source is provided by a single incandescent 60W bulb (the type that you put in chandlier fixtures).
The eggs are from Anconas and Welsh Harlequins (both currently at the top of the North American Conservation Priority list, for domesticated poultry).
http://www.albc-usa.org/wtchlist.htm#ducksIf I'm lucky, they'll turn out like this:
Ancona:
Welsh Harlequin: