bald patches under wings and back
Hi I just got a budgie for the first time about two weeks ago and I dont know if this is normal but I noticed my budgie has what look like bald patches under his wings and back (only visible when he stretches his wings). They look dark and white so Im not too sure if theyre bald patches or just different kinds of feathers (he is green). He doesnt seem to be in pain and seems generally happy (he is sometimes a little fidgety when someone gets too close but I just got him so thats to be expected).
I got him from a pet store that seemed a little sketchy so idk how well they took care of him and hes had these patches since I got him. Again, Ive never owned a bird before, is this something I should be worried about or do most birds have this?