Duck egg with weird air sac

[IAM1999]

Hi everybody! A few weeks ago a friend called me because a wild duck sitting on a nest of 11 eggs in her backyard was killed by a cat. This was very sad ofcourse, but we hoped we could maybe save the eggs. The duck had been sitting/incubating for about 1-2 days. The eggs had been cold for some time tho. I candled the eggs and saw development in every egg. I decided to put the eggs underneath a broody hen and hoped for the best. After a few days I decided to candle them again. Sadly only 1 egg had survived. Now, at day 22/23 I candled the egg again and found that the egg has a very weird shaped and big air sac. It takes in about 60% of the entire egg. On one side of the egg, the air sac runs from the base of the egg almost up to the pointy side of the egg. I do see clear veines and some movement in the “dark part”, so the chick is still alive I guess. Does this egg have any chance of hatching? I worry there is way to little space for the duckling to develop properly. I will try to post a pic of the candeling tomorrow. Thanks in advance for your reactions/answers!!

P.S. Sorry for my bad English, Dutch is my native language.

 

[Debbie292d]

Since it's still moving, it must be progressing. I've seen some strange air cells even in my own chicken eggs and about 50% of those will still hatch even if it's on the side of the egg.

Assuming you aren't in the U.S. as most would not be posting we did this as they're protected. It's awesome though that you did try to save them! Hopefully, that one hatches.

 

[Vixen with Chickens]

Duck eggs need more moisture, the large air sack is from too much water evaporating from the egg. people normally spray them with warm water once a day starting at day 10.