Why is there Air Space?

[Lacrystol]

I have two call duck eggs and when I candled them last night, I noticed quite a bit of Air space, I could see the duck moving what does this mean??

 

[Mum]

Air space has something to do with moisture evaporation ( I *think*) Not entirely sure.

You may find this thread helpful re: air space and duck moving: https://www.backyardchickens.com/t/491013/goose-incubation-hatching-guide-completed

 

[ariel4birds]

The air cell in duck eggs gets larger as the incubation progresses. By the last couple days of incubation, the air cell is much larger then an air cell of a fresh egg. About 2 days before a duck eggs is due to hatch, the duckling will puncture the air cell membrane and start pecking at the shell from the inside.

The air cell helps the egg "breath." Gas exchange. If you're incubating duck eggs, sometime the air cells can get too large if the humidity is too low in the incubator.

 

[ariel4birds]

Check out this image. It's a graphic of air cell evaporation by week. Keep in mind this is for a chicken egg. http://www.google.com/imgres?q=duck...0&ndsp=18&ved=1t:429,r:4,s:0,i:75&tx=83&ty=48

 

[Lacrystol]

Ok but these two eggs I can see from the top of the membrane to where the duck is I can see in the middle of the egg below the membrane. . Is this normal? I can still see the duck moving...