I glanced across the aisle and saw a sulphur-crested white cockatoo perched on a passenger's shoulder. I got out of my seat, found a flight attendant, and quietly told her about it.
She waited until I returned to my seat, and then she walked down the aisle and said to my fellow passenger "Is that a bird?" I'm glad I had a magazine to hide behind so no one could see me choking with laughter!
The flight attendant made the passenger put the bird in its cage.