Cockatiel enclosure, Sept 2011

Do you know by any chance whether these are domesticated or wild cockatiels?

I would guess they are aviary bred.

I meant: are these birds 'pure' (the original wild species) or just common domesticated cockatiels (are there for example 'mutations' in this aviary? Birds with different colors than only the standard grey color)?

I've never been here, but I can see in the photo above a whiteface, a cinnamon and a lutino, along with some wild morphs.

For some years now the cockatiel breeders in Australia have been lamenting the fact that you can't get purebred cockatiels anymore, they all carry at least one mutation.

Is it strictly illegal to go out and capture some individuals to bring unmutated stock back into the captive population? Aren't cockatiels considered agricultural pests in some places? Seems strange that if they are that capturing some (as opposed to destroying them) wouldn't be allowed...

It is illegal to take anything native from the wild without the correct permits. There is however, a lot of people that do illegally take from the wild purely for profit.

Some years ago budgerigars were legally collected and marketed as "Bush Budgies", because the things in captivity today are much bigger than the wild form. Maybe they will do the same with cockatiels one day.

How difficult is it to see wild cockatiels? Do they occur in urban areas like Sydney and Melbourne as backyard birds?

They certainly don't appear in Sydney (except as pet escapees), and I've never seen them in Melbourne or Brisbane. They are generally considered to be found west of the Great Dividing Range in more arid environments.