Duck Egg External Crack but No Hole after 24hours

[taliam]

I have a late hatching mallard duck egg (today is day 30 or 31). I had found the duck egg abandoned and decided to incubate it myself. Everything has been progressing great, and I think the late hatch is due to the egg being left uncovered for about a day or so.
The egg internally pipped yesterday morning. By 8pm that night, I saw the first little crack in the shell. This morning there seems to be no progress- still just a small crack, but no hole. The duckling is moving a lot though and I can hear lots of tapping on the shell and occasional chirps.
I am just wondering if and when to intervene (if I need to). Is there a time when I should be worried that there is no actual hole in the egg? I just want to ensure that the duckling can breathe and has enough oxygen. I'm worried that if he doesnt make a hole soon, he won't have enough air.

 

[BirdsBeesTrees]

Put in a safety hole and be prepared to assist.

 

[taliam]

Put in a safety hole and be prepared to assist.

How do you suggest I begin to go about this? Should I start by peeling the part of the shell that is cracked, until there is an air hole?

 

[BirdsBeesTrees]

If there is a crack I'd start from there.

 

[AquaDuck]

I have a late hatching mallard duck egg (today is day 30 or 31). I had found the duck egg abandoned and decided to incubate it myself. Everything has been progressing great, and I think the late hatch is due to the egg being left uncovered for about a day or so.
The egg internally pipped yesterday morning. By 8pm that night, I saw the first little crack in the shell. This morning there seems to be no progress- still just a small crack, but no hole. The duckling is moving a lot though and I can hear lots of tapping on the shell and occasional chirps.
I am just wondering if and when to intervene (if I need to). Is there a time when I should be worried that there is no actual hole in the egg? I just want to ensure that the duckling can breathe and has enough oxygen. I'm worried that if he doesnt make a hole soon, he won't have enough air.

You only need to make sure the membrane is punctured. Remove one piece of the shell and pinch a tiny hole in the membrane. As small as possible really, it's only to ensure it can breathe.
I always do this with my duck eggs, since they can go days between ext pip and zipping.