firstly we need to learn more about their upkeep and housing. 

First off you need to research care of Mandarin ducks, because they are not the same as domestics. Mandarins need a covered aviary set up, no exceptions. These small tree ducks need protection from all predators. Hawks, cats, and even crows will try to prey on these little ducks if left in the open. So, if in an enclosed aviary, the next door hens shouldn't be a problem. Mandarins (even wing clipped or pinioned) can easily clear a four or five foot fence and if not fly over it, can climb it with ease. Of course if neither wing clipped or pinioned the Mandarins will simply fly away. For a pair of Mandarin ducks, the minimum space requirements is 100sq feet. A 10 x 10 aviary is ideal. Anything smaller than this and the Mandarins will hurt themselves flying into the walls. The aviary should be at least six feet high and covered top to bottom with hardware cloth. NO CHICKEN WIRE or anything larger than 1/2 inch spacing. Not only is the larger mesh not predator proof, but in an enclosed space, Mandarins with their narrow bills can and will get their bills caught in the larger mesh. They will need a small, well bedded house within the aviary to retreat to when they feel cold. If they are fully flighted the house should be placed up high, as they will feel more comfortable using it. The house should not be much bigger than 2 X 2  and about 16" high for a pair of Mandarin. No more than one pair (Male and female) should be kept to an aviary, otherwise fighting will occur. Both males and females fight over territory. You will need to provide branches for them to comfortably perch on and two nest boxes designed for wood ducks in the enclosure. If you do not provide the nest boxes, Mandarin females will go egg bound from lack of appropriate nesting sights. If you are planning on hatching young, be prepared to repeat this set up for each pair of Mandarin you intend to keep. Or at the very least, an all male aviary and an all female aviary along with a grow out space for the young. I don't suggest breeding Mandarins unless you have a lot of space. A good feed ration is important for Mandarin Health.