myster_pda wrote:1. How does Michael know that 15 mins/week are enough? The amounts I found vary wildly.
It's what a breeder told me and something I've tried to stick with when I can and the birds seem to do well. It's a minimum, a starting point.
myster_pda wrote:2. How concerned should we be with too much sun? If the above figure is right, am I leaving him for too long? We don't get much sun in our home so it's just a few hours per day, next to the window. I usually leave him there for the whole session.
Too much is when the bird has had enough, they should have the choice to get out of it. In an aviary, provide shady sports. On your shoulder (with harness), allow them to hide in the shadow of your head. So, basically I try to get them in direct sunlight for 15 minutes straight. Then beyond that, it's just outdoor fun time and not about sun any more. Keep in mind it takes much longer if it's a little cloudy, sun is setting, or it just isn't intense for some reason.
myster_pda wrote:3. Does UV pass through windows meshes (screens)?
No. Or even if it does, the intensity wouldn't ever be sufficient. This kind of light is just for fun. Keeps the room lit, maybe a more natural color temperature. But it doesn't serve the same purpose as being outside.
myster_pda wrote:4. How to manage heat? I have a parrotlet and he seems to like the sun. I leave him on the balcony with the sun hitting part of his cage, though the window mesh and, now that trees are green again, some leaf shade. I've never seen him panting or anything but summer is coming.
When it's hot, I spray down the birds because water absorbs heat really well. If it's over 100, gotta rethink taking them out at all.