This nifty little book does a a great job explaining all kinds of cockatiel mysteries. Why do cockatiels whistle, gorge on seeds, grind their beaks, lose their feathers, regurgitate to a significant other, sleep on 1 foot, preen, poop so often, produce dust, lay eggs without a mate, and just about anything else you've ever wondered! This book will provide you the answers you've been looking for and strengthen the relationship between you and your bird.

Why Do Cockatiels Do That? by Nikki Moustaki, 72 pages.