Is it normal for shell of air cell to become darker on day 25 duck eggs?

[Charlotto333]

I am now on day 25 and have just removed off turner and placed on hatching grid for lockdown. Plus filled second water reservoir and reduced temp from 37.7 to 37.2 (as per the Borotto incubator instructions). Yesterday, it appeared a lot of my eggs were already shadowing in air cell, which did make me a bit concerned as to whether I should have lockdown a day early? And today, some have definitely internally pipped, making audible chirping. However, is it normal when they have internally pipped, for the shading of the air cell shell to become dark? Is this just the ducks body shading? I’ll attach a photo. There’s also another egg that looks like it is bruised on the shell, but I’m hopeful this is a good sign that it is trying to externally pip ?

Also, i should have asked before lockdown, but is there a preferable position when laying eggs down on grid for hatching? Is it best to lay them with the dropped down air cell resting on bottom, or placed with the bulk of the air cell facing upwards? It might sound silly, as I’m guessing in a day or so, they start rolling about anyway, but thought I’d ask anyway.

Thanks in advance anyone!

 

[Susan Skylark]

If it is just one or two eggs I’d candle them, may be quitters and what you are seeing is the fluid and solid separating. If it is the whole batch then whatever it is it is ‘normal’ for this bunch and I’d just watch them.

 

[Charlotto333]

If it is just one or two eggs I’d candle them, may be quitters and what you are seeing is the fluid and solid separating. If it is the whole batch then whatever it is it is ‘normal’ for this bunch and I’d just watch them.

It has only happened to 2 out of 13 eggs (and I wouldn’t say they are both the exact same description either, as 1 was just lightly yellow bruising near air cell, and the other, turned a dark shade over about half the egg) . That was the one I was most concerned about, despite candling prior to lockdown when it was this colour and still seeing movement/sound from inside. I’m happy(? I think) to report that the egg has since pipped it’s shell though, and looks to be on track for the first one to zip too. The other bruised egg has also pipped early this morning, along with 4 more. So currently have 6 out of 13 pipped, and hatch day (28th day) is meant to be tomorrow evening.

Fingers crossed!