Rabbit cages are great for cage training your birds if you show. They are also good for putting broodies in if you don't want them brooding. And, lastly good for seperating sick, injured or quarantining new birds.
Rabbit hutches are saviors for people with chickens
They aer great for chicks that are a step up from whatever you've had them in since newborns, great for broodies and babies, or if it's big enough, for a breeding pen for bantams! We have a nice sized rabbit hutch we use as a grow out pen for the chickies until they are pretty much full grown and can be thrown in with the adults.
I have been considering lopping off the legs of my rabbit hutch, so that the hutch will be almost sitting on the ground, and then attaching a "run" out the door of the hutch (and making sure all is secure to keep predators out).
I only have one silkie right now, and plan to get just one or two frizzles (all bantams).
I put wood sides on the hutch, already, to keep the wind from blowing straight through.
It should be like a little coop.
And if I put wheels on it, I can drag it around the yard to avoid killing the grass in one area.