Cockatiels are small birds commonly kept as pets due to their friendly nature and low volume. Cockatiels are nearly 7 inches tall when full grown and have a full body, a long tail and a crest of feathers on the top of the head. They come in a variety of colors, and usually have an orange spot on the cheeks. It may be possible to determine gender by 9 months of age based on color changes under the tail and wings.
It is impossible to accurately determine the gender of a cockatiel until it's 9 months old. At this time, females will molt and grow in new feathers that identify them as different from their male clutch mates. Female cockatiels have spots or stripes, called bars, under the tail feathers and wings. Around this time, the male cockatiel's face will become a brighter shade of yellow than the female's, and the orange cheek spot will be more vibrant. In whiteface mutations, the white on the face becomes brighter, but there is an absence of a cheek spot in both genders.
A cockatiel's color can be determined as soon as the baby grows in its feathers. The standard color is gray, with the male having a yellow face and orange cheek spot that is brighter than the female's. Lutino cockatiels are completely yellow, or yellow with white on the wings, and have red eyes. Pearls are gray with a sprinkling of white or yellow spots on the body and wings. In males, the pearling will disappear as sexual maturity is reached, while females will retain their pearling. Pied cockatiels have a base of yellow, with gray splashes on the body or wings. Pearl pieds look similar to the basic pieds, but have the pearling on top of the gray areas of the body.
There are many color mutations that are the result of selective breeding. The most popular are the whiteface mutations, where the yellow color and orange cheek spots have been bred out, leaving a solid gray or solid white face. Whiteface mutations come in pearl, pied and pearl pied.
According to the American Cockatiel Society, the breed standard that judges use in the show ring is based on a 17-inch bird. The body and tail should each be 7 inches while the ideal crest is 3 inches. The body should be full and the head well rounded, with no bald patch under the crest. The wings should be long and held close to the body, while the body feathers should be smooth and have no frayed or missing feathers.