When I have baby birds, I house them in a homemade brooder (a 10 gallon glass aquarium) with pine bedding and a reptile heat bulb. I have had great success with this set-up. When the babies get older and are starting to perch, they are upgraded to a weaning cage. The specific cage depends on what I am not using in the birdroom, but is normally an 18"L X 18"W X 24"H cage. I do not put a grate in this cage and I use paper for the bottom along with fleece in case the babies fall from the low perches.

Briana-BareFoot Aviary