Currently, my family has two parakeets. We know that male parakeets have a blueish-purple cere, and females have a peachy-white cere. However, one of our parakeets ceres has changed from a vibrant, certain blue to a peach color (since purchasing the bird seven years ago), and is taking heavy interest in the nesting box recently put on the cage. I can’t imagine it’s possible for a parakeet to change gender, but that’s the only explanation I have. We have never had our birds sexed by a vet, as we live pretty close to the middle of nowhere. We’re sort of dumbfounded! Not that breeding our parakeets is out of the question– we’d be happy to have chicks!
Our other parakeet was home bred ten years ago and has always had the male purpleish cere, and is also taking interest in the nesting box.