Thanks for posting this Charis. Lots of good information.
Another thing that works good for keeping birds warm is the reptile heaters. They come in 40, 60, 100, 150, and even 250 watts. They're great, and don't throw any light, just warmth. They can be adjusted by how close they hang over a tank or cage, and of course, you would keep a thermometer in the nest or box where the bird is kept. I love these, and the temps stay where you want them without much fluctuation.