Don't really know if you would call these brooders or not. I use it them as broods/pens.
Plastic curtain used to keep heat in on young quail.
2 week old quail
Young Araucana chicks
older quail
My Brooder made from scraps. Found an old kids bed on the side of the road and used it to make a fairly nice brooder. Used other scraps of lumber I had around the house.