I'm sure this is going to sound like the most idiotic question ever

, but I need to know.
Would a male bird be attracted to a female bird during mating season if they are two different species? (Cockatoo & Cockatiel)
It is possible, but like you've already been told, whether they get along, is totally dependent on the birds involved, though I don't know if I would let a hen 'tiel interact with a male rosebreasted, especially if he tried to mount her, I would be afraid he might hurt her in the attempt and you could receive a serious bite, trying to save your 'tiel.....if nothing else, I seriously doubt she'd be able to support him to begin with.....that being the case, I think it might be considered abuse to even let them try to interact...I would think that any eggs generated would be larger than a 'tiel hen could pass successfully.....why would you consider letting these two interact in the first place?
In the case of the galah & the 'tiel, the sexes were reversed.....and they had been caged together for a period of time, with the owner not thinking anything would happen between them either.....