To know the sex of a bird is sometimes quite easy and other times quite difficult. Some birds can be sex by visually looking at the bird. An Electrus is one of these. An Electrus female is red. But the male is green. So you never have a doubt on which sex you have. There are other birds that can be visually sexed. A Cockatiel is one. I'm not as great on sexing Cockatiels unless they're grays and so forth. But if you raised the wing of a Cockatiel it will have a yellow band under it. If that band touches the body its usually a female. if it does not it only goes halfway down its a male. I usually remember that because they say females like to be touched. So if the line touches the female's body its a female. The patch on a Cockatiel is not a way of telling the sex of a Cockatiel which a lot of people think there is. There's also a way of knowing the color of the crown of the Cockatiel that it will tell you the sex. If you look at Tiara's eyes her eyes are brown. A female's Cockatoo's eyes are brown and the male's eyes are black. Why this comes about, I don't know. But it's the way it works. And so if the eyes are black on a Cockatoo they are male. If their brown they're female unless its a very young bird. A very young male might also have brown eyes. But once it starts getting up in age a little bit you can easily tell that if its eyes are black that it is a male and if its eyes are brown it is a female. On birds like Amazons most your Conures, Pionus and other birds the way that you will know the sex of that bird is either to have it DNA sexed or to have it surgically sexed. Guessing is just that a guestimation. You can be right, you may be wrong. You got a 50/50 chance because they're going to be one or the other. But to know for sure the bird has to either be DNA'd or surgically sexed. Because I'm a breeder I usually have my birds surgically sexed because the Vet also checks the kidneys, the liver and the reproductive organs to make sure that they're in good order. This is not a harmful procedure to the bird. He makes a very small slit with the bird under anesthesia and checks the bird. By the time he's finished the bird is waking back up. And so it doesn't really hurt the bird and you also know that you have a good healthy bird.