The easiest way to know the sex of a canary is that the male sings, the female does not. The distinction of the sexes can be made with the naked eye by observing the different formation of the anal area during the breeding season. In males it is protruding, while in females it is rounded.
Other differences are in the pens surrounding the genital organ, longer in males. In the shape and dimension of the head, it is slightly larger and rounder in males.
What is bird sexing?
Finally you can find out sex by sexing is a method to determine the sex of an animal by DNA. In the Canaries it is not common to use this method, but it can be used in canaries, inseparable (lovebirds), nymphs, macaws, cockatoos, parrots and exotic species. There are companies such as BBI laboratories that are dedicated to sexing, it is an Andalusian biotechnology marketing company.
It can be performed by DNA analysis, by behavior or by morphological characters. Sexing is performed by analyzing a DNA test (usually saliva, hair or blood) in search of sex chromosomes.