Sexing your pet parakeet comes down to looking at their cere, the fleshy part above the beak where the nostrils are. The cere color changes between breeding and non-breeding males and females. You'll have no luck, however, if your budgie happens to be under 8 months old.
Step 1
Study the cere of your budgie. One look should be sufficient. Breeding males have a dark blue (normal varieties), bright violet or bright pink (lutinos, albinoes, lacewings, recessive pieds and fallow mutations) cere. Non-breeding males have a pale brown or pink cere. Females, on the other hand, have a brown, beige, white or pale, light blue cere. Immature budgies typically have a pink cere no matter their sex, although young males may have a slightly purplish cere.
Step 2
Study the behavior of your budgie, although you'll have more luck if you have more than one parakeet in the cage that are of different sexes. Males generally are more active and outgoing, eager to play, and bob their heads and so forth. Females tend to be more aggressive than the males, as well.
Step 3
Listen to the songs and noises your budgie produces. A short, angry sounding chirp outside of a song typically is a female. The males make this angry chirp as well, but it's typically mixed in with a melodious song.
References
Writer Bio
With a professional background in gardening, landscapes, pests and natural ecosystems, Jasey Kelly has been sharing her knowledge through writing since 2009 and has served as an expert writer in these fields. Kelly's background also includes childcare, and animal rescue and care.