There are 2 ways to learn the sex of our budgie: The first one is the colored area just above the beak where the nostrils are, which we call the “cere”, which will give the most important and definitive answer, although its behavior and movements can also give some clues. It is necessary to wait 6 months for the color of the cere to fully settle. If your bird is 6 months old, you can now clearly name it. The cere of male budgies can be baby blue, purple, or dark pink. Female budgies can be determined by the color of the cere being dark brown during estrus, that is, during the breeding period, and yellowish, dark brown or off-white during maturity. According to their behavior in the cage, male budgies sing more often and usually shake their heads while singing, while females are more sedentary and aggressive.