There are a few ways to tell the sex of a cockatiel. Firstly, and most presisly, there is DNA sexing. You can go to the local vet to have this done. Secondly is by behaviour. Males will be more vocal than females, and will whistle and talk, while female somewhat lack in that department. And thirdly, there is visual sexing, this only works with normal greys and some pieds. I know this does not apply to your bird, but it is good to keep in mind. If it is a young bird, then this will not apply, either. There will be bars under the tail and grey over the cheek patches if female, while males have bright, clean faces and fully grey tail feathers. Young birds will have dirty faces and bars. With pearls (yours isn't) males lose their marking as they age, while female keep theirs. Personally I think Buzza is a male. Hope this helps you, Ezza.