What bird is this?

At the beginning of February, on a camping trip to Wilson's Promontory National Park, I saw a fledgling bird and to this day I have no idea what kind of bird it is. I like birds, and I like to watch them, so while I'm not an expert bird-identifier, I'm no slouch in the department either. However, this young bird has me completely stumped. If you know what kind of bird this is, please let me know!

Update: It's a juvenile eastern yellow-robin. Thanks, everyone!