by Navre » Sat Apr 23, 2016 9:20 am
You can build a frame with hardware cloth and put it in the window, just like a window fan fits. If the bird is going to be unsupervised, you will probably want to avoid the usual, galvanized stuff, as it is coated with zinc. Stainless steel is more expensive, but you won't be needing a whole lot.
If you can't find stainless, I've heard that washing the galvanized stuff with vinegar makes it safer for th birds. I don't know how this works. I suspect it removes a layer of powdery oxidation that is easy to ingest. It won't, however, help if the bird chews off a piece of the coating.