chicken incubating chicken & duck eggs?

[Rachel's Hobby Hatchery]

Hi, I have herd of people doing this so I tryed it. Maybe I did somthing wrong?? there were 5 eggs total, 2 chicken, 3 duck. the duck eggs were layed within 3 days and the chicken eggs were layed within the same 3 days. There were origanally 5 chicken eggs & she started sitting on them. when she started sitting I switched the chicken eggs for the duck eggs (that I was leaving in a nest hoping somthing would brood them). I wated and wated and finally they started hatching! first one chicken then the next day the other chicken. I kept checking for duck hatchlings but none hatched and the hen finally gave up on them. I broke two of the 3 eggs to see if there was anything in them & if they were developing right. I found one was black & almost ready to hatch (maby another week or less) the other was tiny & white & had several weeks of developing left. The other egg I gave to my one duck that had recently decided to sit & it hatched 2 weeks later.
I thought the incubation times were the same for chicken & duck eggs? all of the eggs were the same size & she sat on all of them. They all stayed warm... I dont know what went wrong? Please help.

 

[crazy chook]

Hi, congratulations on your new chicks.

Chickens take 21 days
Ducks eggs take 28 days
Muscovey eggs take 35 days

hope this helps.

cheers

 

[sourland]

21 DAYS for chickens, 28 days for mallard derived duck breeds, 35 days for muscovy eggs. The ducks needed at least one more week to hatch. Two more weeks if they were muscovy eggs.

 

[Rachel's Hobby Hatchery]

she did sit on them for one week after her chickens hatched. They were call ducks, not muscovys.

 

[honeydoll]

Call ducks are the hardest eggs to hatch. They are notorious for having bad hatches. I am incubating some and have a broody on the others. We'll see what happens.

 

[Rachel's Hobby Hatchery]

I herd that they were easy to hatch. Why are they so hard to hatch?