Muscovy cross? Candeling eggs?

[MinniesMomma]

This is my Drake Hank. What I know for certain about him is that his dad was a black Swedish. Mom could have been khaki Campbell, Blue Swedish, or one of four Muscovy. I realize the odds are pretty good that he is a Muscovy cross and would therefore be sterile. But right now I have three girls sitting on nests with dozens of eggs. What am I looking for when I candle to see if any of them are good? My ducks live on a lake where they are visited by wild ducks, and I know it's uncommon, but I do have one hen that is a cross from one of these wild ducks. I don't want to get rid of viable eggs, but I also don't want to deal with infertile eggs that have been sitting under a hen for 35 days.

 

[AvianBrain]

His general shape does look muscovy, If a black swedish drake (Domestic mallard breed) to a muscovy hen, this cross is called a hinny, which do tend to look a bit more like the father. I have read that hinny drakes do have a very so slight chance to be firtlie, if somehow he is, you could bring in new genetics and never before seen paterns and color types. It is REALY unlikely though that he is firtile. When candling eggs, look for a red dot in the yolk area with vains, lots of pictures out there, you could always crack a few to see anything. An older embryo looks more like a large "shadow" twards the pointy side of the egg. Most hens "Reject" bad eggs by pushing them from the nest, Thier UV vision can tell a healthy egg/chick from a bad one, But my Mallard hen sat on like 40 eggs before, and They don't have access to any drakes. Best to look on google images for candled firtile duck eggs, it's different depending on the stage of development.