The 3 male Siamese cats I've had never showed any interest in birds. Probably it was too much bother to chase them? Unfortunately, they also had no interest in catching mice.
My neighbours' female cat, on the other hand... http://www.flickr.com/photos/diffuse/7164051959/
I've read that female cats are the hunters and males are the fighters/defenders of territory.
Back to the original question, when I first got the kittens they were only outdoors if I was with them. I taught them their boundaries and that the road was out of bounds. As they grew up and when they were adults I only let them outside when I was at home and could watch them. They stayed safely in their own yard, with only occasional verbal reminders needed. I don't know if other breeds are as easy to train as Siamese?
McGrath, If the road beside my house was as dangerous as yours sounds, I think I would have put up cat proof wire screening barriers to make it next to impossible for any cat to go out there.