How to tell if duck abandoned it's nest?

[Functional Rustic]

My Muscovy hen was sitting on a clutch of eggs for about 2 to 3 weeks but as of a few days ago she has stopped laying on the eggs. It is below freezing here and the formerly toasty eggs are cold. Worth noting, the Bronze Turkey Hen she shares a stall with also used to sit on the eggs and she stopped too.

Questions:

Has she abandoned the nest?
If so, why would she abandon it?
How long do I wait to remove the eggs?
Can I prevent this from happening in the future?

Thank You!!

 

[Miss Lydia]

Could something have scared them off for good? If she has been off the egs for days I'd say they are worthless and should be tossed out. Muscovy's are great broodies and I don't think they abandon unless provoked to do so. Make sure they have a private secure place to lay and brood my Muscovy's love their privacy while brooding so I have made several areas that are secure for them to lay and sit. They cannot get up under anything either I have had to make sure of that.

Take the eggs and candle before throwing away just to make sure there was life in them. To be sure they were fertile.

Are these girls both young?

 

[Functional Rustic]

Could something have scared them off for good? If she has been off the egs for days I'd say they are worthless and should be tossed out. Muscovy's are great broodies and I don't think they abandon unless provoked to do so. Make sure they have a private secure place to lay and brood my Muscovy's love their privacy while brooding so I have made several areas that are secure for them to lay and sit. They cannot get up under anything either I have had to make sure of that.

Take the eggs and candle before throwing away just to make sure there was life in them. To be sure they were fertile.

Are these girls both young?

The hens are about 8 months old. These eggs are in the nesting box....as of an hour ago each of the hens have started to build new nests in the straw...middle of the walk way. Ha. No eggs yet but definitely building something.

I candled some of the eggs a week before she abandoned them and they were at different stages of gestation...I think. I'm new to all this - but some had distinct dark masses while others had smaller dark masses.

 

[Miss Lydia]

No telling what could have made them give up.