Mama duck new to hatching help!!!!!

[sieradon]

I have a female mallard who is sitting on 17 eggs right now. Most are fertile however not all hers. The khaki female she is rooming with is laying on the same nest. For the last week I had to throw away 3 fertile eggs that have rotten and turned to water. Is this normal for a first time mother duck? She is on a nest but the nest is not under a roof. When it rains the nest gets wet will that do it.

 

[sourland]

17 eggs are far too many for a mallard sized hen to incubate effectively. Part of the problem is that additional eggs are being added to the clutch.

 

[sieradon]

So take some out? How many are normal?