Once a budgerigar is a few weeks old, you will be able to tell the sex of the budgerigar by looking at its cere (the nose and nostril area). In normal circumstances, a hen’s is brown, and a cock’s is blue. The hen’s cere becomes enlarged and scaly during the breeding season, and the male’s becomes a darker shade of blue.
But there are a few complications. Hens sometimes have a light blue cere, when their breeding hormone levels are low. It will also be this colour, or white with just a hint of blue, if the budgerigar is ill. In the wild the female’s cere is light blue, turning brown during the nesting season. In young hens, the cere is a light blue with white around the nostrils.
Cock budgerigars, although nearly always sporting a blue cere, may have a brown or brownish-pink one if his breeding hormones dip, or if he is ill. An ill male may develop a yellow-greenish tinge around the nostrils too. In immature cock budgerigars the cere is a blueish pink or light purple.
Some budgerigar types are harder to sex. Albino, Lutino and Mottled budgerigars, for example, have off-white, light pink or bluish pink ceres, and males of some of the pied varieties have light pink, blueish pink or white ones. With hundreds of variations on the basic types, there is always a chance that your budgerigar will have an ‘ambiguous’ cere colour. In 90% of cases, however, the brown-or-blue rule applies.
In spite of these complications, cere colour is still the easiest way of sexing budgerigars. There are a few gender-related differences in voice and behaviour, too; but these are not as consistently ‘male’ and ‘female’ as cere colour. If you inherit an adult budgerigar of unknown sex and with an ambiguous cere, watch out for bonding behaviour – any excessive head-bobbing is likely to be a male, and any excessive squawking, rather than chirruping and singing, is probably female.
Younger budgerigars of all types are harder to sex than adults. By three weeks old, cocks have a blueish-pink cere, sometimes verging on lilac, and females have a blueish white one, usually with pure white around the nostrils. If the young budgerigars belong to the Albino and Lutino group, you won’t be able to sex them without an internal examination – which is something you should never attempt in any circumstances. Time will deliver the answer, and there is no need to interfere with the budgerigar during its early weeks.