Male and female canaries look very similar, and it is difficult to identity a bird's sex; however, there are a few ways to find out if a canary is male or female. Generally, bright-colored feathers indicate a male, and dull-colored feathers indicate a female.
In some cases, a female canary exhibits nesting behavior by gathering items to construct a nest. If the canary sings on a regular basis, this is indicative of a male. Examining the physical sex of the bird is a definite way to determine whether it is male or female. The male has a slight appendage, and the female does not.