I keep birds, I'm not sure I'd want any of my smaller birds to travel that far. Although having said that, I know in America, birds can be sent through the post! A lot of people buy day old chicks in their hundreds and most arrive safe and well after three days in the postal system. :shock: So I guess they must be tougher than I give them credit for!
Can you get in touch with the airline and ask how noisy/cold etc it is in the hold? And ask if anyone can check on them during the flight? (I assume there's a way into the hold from the inside of the plane?!). I know when there's livestock on board, they are supposed to turn the heating on for them. I remember watching one of those airport programs on the TV and a shipment of reptiles came in dead because they'd forgotten to keep the hold warm. :shock: If it's warm and not too noisy, I'd try it. Providing budgie is in a nice secure cage with light (18 hours of dark is not good for birdies) and a food and water supply that won't spill on takeoff. Same for bunny I guess. If she's a laidback bun, I should think she'd be ok. Maybe start giving bunny access to it's travel box now so it smells familiar, it'll help keep stress levels down if it feels kind of like home. Get both vet checked before you go and when you land to make sure they're fit and well.