A cockatoo’s whistle is similar to our human whistle. It's a greater pitch than ours, and is usually recurring many periods. Trill Answer: A trill can be a series of shorter notes played fast. Both of those males and women have dim orange or purple stripes on their own tails. https://amazon-parrots-for-sale59222.blogzet.com/the-2-minute-rule-for-amazon-parrots-for-sale-34726461