Chirps, warbles, and whistles are not the only sounds that this little parrot can make. Many are perfectly capable of mimicking human voices. They will mimic a lot of noises that they hear regularly so you can expect a thoroughly convincing alarm call at any time of the day. One of the times when a cockatiel is likely to speak or make another noise is when you leave the room. This inquisitive little gesture is equivalent to the bird trying to determine when you will be back. Whistle back and it should put your 'tiel's mind at rest. Like many of their cousins, Cockatiels originated in the Australian continent, thriving in the arid scrubland of that nation's hinterland. Coming from those harsh conditions, cockatiels adapted perfectly to the milder climates all over the world, requiring very little in order to be happy and strong.