The Gloster canary was bred to be short and stubby, less than 5″ in length. Not all Glosters sport the fancy Beatles style hair-do.  They are noted for their beautiful song, which coupled with their cute appearance, makes them a popular pet. Interestingly, breeding two crested canaries does not work. The resulting chicks form with skull deformities and usually die in the shell. In order for viable Gloster canary chicks to hatch, a crested Gloster must be bred with a non-crested.