Help with eggs--Possibility of hatching or no?

[Cuppycake243]

A few weeks ago a wild mallard laid her eggs under a bush by our pool, eleven in total. She sat on them for a while, then I suspect my older Labbie scared her off and something happened to her while she was gone. Three eggs were missing from the nest and the only sign of something happening to them are shell fragments that ended up at the bottom of the pool. After an unknown number of days of her being off the eggs, I removed the remaining eggs and candled them, burying the definitely dead eggs and making a makeshift incubator for the ones that may still be alive. Sometime yesterday, a couple started showing black patches on the shell that look like its something going on on the inside. I have not found any definite answers on what this might be an indicator of as of yet and would like to know if this means they are definitely dead.
There is not much I can say with certainty other than that they were fertile when they were laid. I do not know exactly when they were laid. I also don't know how long the mother was off the nest. These eggs do not smell, so as far as I can tell with my limited knowledge is that they are not bad yet. One egg smells funny on one area of it, so I think it's just something on the surface of the shell that's causing the smell.
I would really appreciate anything. Advice, feedback, tips, knowledge, whatever. The black is concerning me a bit, so if anyone knows what that is or what that means I would really really appreciate it.

EDIT
"Shadow" pix
Egg 1

Egg 2

Egg 2 has the most dramatic "shadow", so I wanted several different angles of it.
Egg 3 does not appear to have any of the shadowing that the other three eggs have.
Egg 4 has "shadowing", but due to the nature of them being wild duck eggs, it has a bit of dirt and debris on it, and it's hard to see.

Candling pic, taken the same way as the candling pix posted by the person whose gosling thread was linked to in one of the replies. Some pix were taken from both end of the egg if possible, mostly because I'm worried about the eggs and if it has a possibility of helping I'll take it, but all were first taken with the light next to the air sac. Some were taken from the same end but rotated. Sorry for poor quality and overall ginormousness of these pictures.

Egg 1:
Air sac end

Opposite end

Egg 2:
Air sac end

Other end

Egg 3:
Air sac end

Other end

Egg 4:
Air sac end

 

[Duckchick2011]

I'm thinking the black patches are bacteria growing in the egg, they may very well be dead, not a hundred percent sure though, I would wait till someone more experienced answers.

From my knowledge black patches on or in an egg are never a sign of something good.

 

[Diamond Wire Farms]

Can you take a picture while you are candling the eggs. That would give us the clearest idea of what is going on.

 

[Cuppycake243]

I wish I had a camera that worked or I would. I could try my phone or my laptop here, but they tend not to have the best picture quality. When I candle I don't see anything that really seems to explain the darker/black patch. I call it black but it is really just dark. There is a similar darkness on another egg that is just on one end of the egg, which I know from cooking is the air pocket found in eggs for hatchlings.

 

[Diamond Wire Farms]

When you candle eggs. The air sac should be lighter or "clear." A dark spot with growing indicates an early growing embryo. A dark blob taking up 1/4 to half of the egg could indicate a later stage embryo. If the hen has been off the eggs for more than 3 days, I would say there is little to no chance of them hatching. Anything less than that would indicate a chance. Here is a link to some candling photos for geese, but you'll get the idea of what normal looks like.

https://www.backyardchickens.com/forum/viewtopic.php?id=472851

And here is a link to a UC paper with a lot of abnormal candling photos.
http://ucanr.org/freepubs/docs/8134.pdf

Good luck!

 

[Cuppycake243]

I'll first post images of the darkness seen on the eggs in the light. I'm not sure how well these will come out, unfortunately, as they were taken with the, while good, limited quality of an iPhone camera. In some cases it looks just like a shadow of sorts. They'll be on the original post shortly, once they upload to my computer and I get them to where I can post them. Then I'll get pictures of the candling of the four eggs, and I will indicate which of the eggs in the candling has the shadowiness.

 

[Diamond Wire Farms]

You're a BYC Newbie

, so if it gives you any flack when you try to post photos, pop by some other threads and tell them their chicks/ducklings are adorable!
Once you have 11 posts, you should be able to upload your photos with no problems.

 

[Cuppycake243]

Quote:
So far it's letting me post em just fine. What's taking so long right now is getting the pictures from the iPhone to the computer, then from where they are saved on the computer to the website where I can then get an image code for them.

 

[cdnley]

I had that on a couple of my eggs. They froze overnight outside which caused them to expand which caused a slight crack to the eggshell. When they warmed up the crack was not visible but it was there. That area darkened up and the eggs never showed signs of veins or growth.

 

[aduckstolemyheart]

I have a momma duck on 5 eggs, and one of my eggs looks the same as yours! Mom is still sitting on it, it still has veining and it does not stink, so I have decided to wait it out. I hope you get some answers on yours, and maybe it will help me too!

Wishing for good luck for both of us!