I've been careful to wrap the cage with blankets before moving him to/from a hotel room for a night, and have made sure the car is all warmed up before moving him from a hotel to the car, so I don't think temperature is the issue. … The strange new behavior is a weird chirp that sounds more like what a raccoon sounds like than a parrot. he's also been very reluctant to 'step up' onto my finger (he's very tame, normally he hops on to my hand before I even get it close to … …

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How does altitude effect parakeets? | USA Hotels