Sorry for the delay - it's been a bit difficult getting to the computer with all the Christmas busyness!. Yes, there is an update - and not a happy one unfortunately. After using the float test and waiting a further day to absolutely ensure no movement in either egg, we did a post mortem yesterday on the 2 eggs and this is what we found:
1. 'Good egg' with the liquid and black 'floaties': we discovered a small, partly grown duckling floating amongst lots of fluid and a large yolk. I'm guessing it probably died 10 days or so prior to hatching, but I have no idea why it died.
2. 'Special needs egg' with the air sac at the pointy end and large vertical space: we were incredibly surprised to find a beautiful, fully formed and mature duckling which had been the dark area that we saw on candling. We hadn't thought that this dark area was big enough to represent a fully formed duckling! The large clear area that we saw on candling proved to be an air cavity which took up over half of the egg, lengthwise. The duckling and the cavity were separated from each other by the chorioallantoic membrane which ran the length of the egg.
The duckling was orientated so that it's face and beak were tucked down into the centre of its body and pressed sideways against the egg shell, with the membrane and large air space running alongside the duckling's back, where I think it would have been impossible for the duckling to reach.
So we figured the poor duckling didn't have enough space to orientate itself into a 'hatchable' position and drowned. Even if we had artificially pipped the egg shell at the side of the air cavity, I don't think it would have been possible to find the beak without breaking the whole membrane and extracting the duckling, so we feel a little comforted by this - that it was a fault of nature rather than something we did or didn't do! Rather upsetting though, to find that we had been so close!
I can upload photos of the little ducklings, but not sure whether this would be considered too graphic or offensive...
The lady who supplied me with the Magpie duck eggs has a commercial incubator with a number of Magpie and Welsh Harlequin duck eggs due to hatch on January 5th. So my daughter and I will try and purchase a couple of 'ready made' ducklings once they have hatched! I'll probably be back on the forum to gather more wisdom on how to successfully raise ducklings then!!
Any feedback is very welcome and thanks so much for your wonderful support!