What kind of eggs are these?

[Renegadeeee]

So, about 3 days ago I found an egg by the porch. I thought one of the dogs brought it up so I took it inside and put heat on it and all that. Then the next day I found 2 more. And the next I found more, and then today I went outside and found 3, 2 were okay but the other was cracked open. So now I have 6 eggs. I put them in this tank on a washcloth, then covered them with another wash cloth, put a lamp on them, and also a heating pad by them. I'm afraid they aren't warm enough because when I touch them they're slightly warm but not too warm. So anyway, aside from that. I want to know what kind of eggs they are. We have Mallard ducks around here, so that was my first thought. Then I saw some geese this morning walking around my yard and I thought maybe they were looking for the eggs but they already had ducklings. Lastly, I thought they were white Egret eggs or this Heron that's always stopping by. I didn't think it was the Heron, because the eggs are the size of chicken eggs. The only birds I've really seen around here was the geese, the mallards, white egret, and the heron. I'm not sure if you can tell, but there's 2 eggs in there that are a bit different from the others. They're a greenish color and a bit smaller. The rest are white, chicken sized eggs. I was going to place them back outside to see if anything would happen, but I'm worried the dogs may get to them. I was gonna buy an incubator today too, just in case. I just need to know what kind they are, if I should do anything else with them, etc. Any tips and help would be appreciated! (Sorry for the long story! xD)

 

[Firekin1]

They look like mallard eggs, goose eggs are large...mallards also lay different shades of eggs from whites, lightish blues, to greens, my suggestion would have been to leave them where they were until you said about the dogs....so now I don't know what to give for advice...lol