What can you teach a cockatiel?

I have a Cockatiel named lilly she can say pretty bird, bad dogs, whistle the food network show GOOD EATS theme song, and loves people and the birds out the window it took practic and a trick to get them to warm up to you whistle them a song i did it to her when my family first got her she loved it and came right to me.

hope this helped- malia