Sound like he;s flying in place. Penny flaps her wings on the perch but does not fly sometimes. They do that for exercise or excitement sometimes. If everything else is fine with them I would not worry about it. He might just be happy but monitor him to make sure he is eating, pooping & otherwise acting normally.
The Budgie Personality and Drive Curiosity & Playing Curiosity & Playing - Every budgie has its own unique personality, but all budgies are naturally curious and playful little birds. Your budgie's antics will entertain you for sure. It is important to foster your budgie's curiosity and...
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Budgies do this by vigorously flapping their wings while hanging onto a perch, flying in place. It’s part of a morning routine to get the blood flowing, and is usually done right after stretching. They often make “mad” sounds while they get into it