I think it depends on the bird.If the bird is well behaved,providing some precautions are made,no ear rings,and if you know the bird well enough to judge mood and temper its not a problem. Problems start when the bird will not step up from the shoulder or runs round your back to avoid stepping up. Also the bird can become agressive if someone else comes near while they are up there.Its a matter of choice an if you are willing to take what could be a very nasty bite. I allow Charlie on my shoulder but I choose a time when he is very mellow and friendley. If he is in a mood, no way.