I am trying to get a few flight training leg rings for my bird. I have budgies, parrolets, cockatiels and Quaker Parrots. I am trying to find the right size rings to get for their little legs. Does anyone know the size to get??

My little approx. 15 week old Ringneck guy makes plenty of different sounds. From loud contact calls, to tiny and adorable peeps. However, there's one sound he makes that I can't quite pinpoint. I've tried looking online for any info about bird sounds, but I can't find anything that sounds like...