You will need TWO separate living areas for your chickens to survive. DO NOT mix chickens with ducks in the same area. Your chickens will not survive.
Please research raising ducks and chickens BEFORE you get them.
Drakes can not be with the chickens.
I raise chickens and ducks together (see sig below). There are currently two adult drakes in with my roughly 20 hens, have been for the last 7+ months.
Don't BROOD ducks and hens together - ducks are ungainly and fast growers, they can accidentally crush a hatchling chick while stumbling about.
Make sure your hens have space in the house up high. Ducks nest on the ground, they aren't going up into your house - your hens will.
I've found integration of new birds (chickens or ducks) with the existing mixed flock works best over a series of weeks when they can safely see and be seen. I favor integrating in the 8-12 week range, when your ducks have some size to them, and enough dexterity (hahahaha) to run from the lead drake as needed. Still, watch for injuries, it can be rough. If you keep a pond, water bath, whatever in your run, keep it well shallow during the first days of contact, or remove it entire - your lead drake may accidentally drown new additions while demonstrating dominance.
Finally, SPACE is a social lubricant. I have a large run (between 900 and 1,000 sq ft) for my flock, and just built a second, larger run, as I prepare to segregate yearlings from this year's crop. Though the birds free range all day. While I've had no issues with randy drakes chasing chickens, as some claim they do, the fact that my chickens can outrun - and have places to run from - my drakes might contribute to a lack of difficulty with that issue.
. Of course our coop will/does have places for chickens to get away from ducks if a problem does arise.
