They are not prone to biting, but will 'strike' and hiss if feeling threatened or frightened. Males are more prone to speaking than hens. I have had some females speak limited phrases, however, but these are rare. Males will speak with a definite 'birdy' voice, but are usually easily understood. Both genders are generally whistlers, able to learn simple songs.
Cockatiels originate in Australia.
They are not limited to a specific region and habitate most of the continent. They are characterized by the crest on the tops of their heads that is a good indicator of the emotions of the bird. Their life span is anywhere from 10-25 years, depending on factors such as diet and overall health. Cockatiels are relatively inexpensive. They are intelligent birds and easy to train.