Maybe you want to get your budgie a pal or a mate, or maybe you're just curious, but you can determine your bird's sex—your adult bird's sex, that is. Budgies under a year old haven't yet developed the telltale characteristics.
Look at your budgie's cere, the fleshy, bumpy area above the beak where the nostrils are located. In adult males, the cere will be a shade of blue, violet or vivid pink. In adult females, the cere is brown, beige or whitish. Young budgies, those under 1 year of age, typically have a pink cere, although young males may have a bluish or purplish tint to the pink.
Listen to your budgie as he or she sings or makes noise. Males generally love to sing melodious songs that burst with happiness; females, on the other hand, typically don't sing as much and will make an almost angry-sounding chirp.
Consider your budgie's energy level and behavior. Males are typically very outgoing, often bobbing their heads or playing within their cages. Females tend to be more subdued and will often become bossy with their flock-mates or even you.