Cuteness on my balcony

They keep on coming back. And now they've started bringing their friends.

So now I want some advice. The first question I have is whether it's really okay to get wild birds dependent on people for their food? (Yeah, I know, maybe I should have thought about this before I started putting out seed.) These ones have been visiting several times a day for the last week or so, and eating everything I give them. And wow, they can really stuff themselves! I'm thinking maybe I should put out less seed, and not so regularly, so that they don't get a nasty shock when I go on holiday.

The other question I have is whether anyone has had any experience (and any luck) with getting birds to take food from their hands? It would be awesome to be able to hand-feed these rosellas, and I suspect it might not be too difficult. Parrots are naturally pretty friendly—the ones I pass in the street are happy for people to stand a couple of metres away and watch them. And the pair that feeds most regularly on my balcony (the ones in the photo) have grown very curious about the balcony door and the people (i.e. me!) they can see behind it. They spend a lot of time walking back and forth beside the door, looking up at me, cocking their heads from side to side, and react with interest, not fear, when I move around. My plan for the moment is to see if I can get them to be okay with me sitting out on the balcony with them while they feed, and if I can get that far, maybe I can start tempting them with pieces of apple or something.

Anyway, any tips or suggestions would be hugely appreciated!