Duck eggs need higher humidity at lockdown and hatching but not necessarily throughout the whole incubation.
I weigh all my incubating eggs to monitor weight loss and check I've got my humidity right, and I've found that duck eggs tend to achieve the correct weight loss with a lower humidity than I normally use when I'm incubating chicken eggs. Lots of people will tell you that duck eggs need higher humidity for the whole incubation, so don't just take my word for it. Go and do some research so you can get all the facts for yourself.
Have a look on Brinsea's website - where you can download their Incubating and Hatching handbook for free. They give you correct weight loss percentages for different species. Also see if you can find 'Keeping Ducks and Geese' by Chris and Mike Ashton on Amazon. You might be able to browse the Incubating section without having to buy the book. They quote 15-16% weight loss for waterfowl eggs, which is higher than the recommended 13% weight loss for chicken eggs. If they have to lose more weight, it kind of stands to reason that they'd need a lower humidity to manage it...
I weigh all my incubating eggs to monitor weight loss and check I've got my humidity right, and I've found that duck eggs tend to achieve the correct weight loss with a lower humidity than I normally use when I'm incubating chicken eggs. Lots of people will tell you that duck eggs need higher humidity for the whole incubation, so don't just take my word for it. Go and do some research so you can get all the facts for yourself.

Have a look on Brinsea's website - where you can download their Incubating and Hatching handbook for free. They give you correct weight loss percentages for different species. Also see if you can find 'Keeping Ducks and Geese' by Chris and Mike Ashton on Amazon. You might be able to browse the Incubating section without having to buy the book. They quote 15-16% weight loss for waterfowl eggs, which is higher than the recommended 13% weight loss for chicken eggs. If they have to lose more weight, it kind of stands to reason that they'd need a lower humidity to manage it...