It can be very difficult to distinguish a female parakeet from a male one, since both genders of this species typically share very similar markings. Breeders generally agree that the color of the cere, or the skin atop the beak surrounding the nasal openings, is a good indicator of the parakeet's gender. A female parakeet's cere will typically vary in hue is it passes through the hormonal fertility cycle, while the cere of a male bird usually remains distinctively blue in color. The female parakeet's cere coloring is usually brownish when it is in the fertile part of its hormonal cycle, but will generally turn pale blue when the bird is not fertile, or if the bird is ill.
It can be even more difficult to identify the gender of a parakeet less than one year of age. The immature female's cere will usually be pale blue with faint white circles around the nasal openings themselves. The immature male's, on the other hand, is often pink or purplish in color.
Many species of bird bear drastically different markings depending on their gender, making it easy to tell males from females. Parakeets, however, generally have the same coloration and markings no matter their gender. Experts typically advise looking closely at the skin of the cere.
When fully mature and in good health, the average female parakeet has a cere that is dirty brown in color. Some female parakeets will display a cere that is brownish in the center and whitish around the edges. In other birds, the entire cere will be brown. The darkness of the cere's hue is generally believed to indicate the level of the bird's fertility, with the darkest colors indicating that the female is most fertile.
If the female parakeet has passed into the non-fertile part of its hormonal cycle, the cere will often take on a pale bluish tint, rather than brown. The cere of a female parakeet in poor health may become very pale, and even turn white. The area will generally return to its normal brownish color within three or four weeks of recovering from the illness. If the area remains very pale for more than a month, the bird may be suffering from a hormonal imbalance.