Sexes are similar, but young birds lack the crown patch.

Without sufficient food, he said, birds would lack the body fat they need.

Sexes are similar in appearance, but young birds lack the red forehead.

Immature birds resemble the male but lack the broken dark band across the breast.

A juvenile bird is similar to the female, but may lack or show only a trace of the yellow tuft behind the eye.

Juvenile birds are brown with dark barring and usually lack white on the crown.

Immature birds lack the red face and have a yellow bill.

The other bird also tried the door, but again, lacked the intelligence to try perching with closed wings.

It was not just the ability to fly that the birds lacked.

The male bird however lacks the white tail feathers of that species.