We breathe in air, not straight oxygen. Attached is a pie chart showing roughly what percentage of what is in the air we breathe
Noctiluca scintillans, commonly known as the sea tinkle and also published as Noctiluca miliaris, is a free-living, nonparasitic, marine-dwelling species of dinoflagellate that exhibits bioluminescence when disturbed (popularly known as mareel). Its bioluminescence is produced throughout the cytoplasm of this single-celled protist, by a luciferin-luciferase reaction in thousands of spherically shaped organelles, called scintillons. Nonluminescent populations within the genus Noctiluca lack these scintillons.
This question seems a teeny bit too trivial for the site but I'll bite: it could be a sign of mating or playful fighting (birds can compete for dominance, like any other animal). If the parrots are of different sexes, it is typical for them to mate if they are in the same enclosure. If they are not able to reproduce, this should cause no concern.
