FAQ: How can we differentiate (the hybrid) sable phenotypes and opaline in blue Agapornis fischeri?
It is good that you realise that the ‘sable’ phenotypes are indeed a selection type on hybrids. ‘Sable’ is nothing else than the blue version of a ‘redhead’ Agapornis fischeri. Every well-educated breeder knows this.
These ‘sables’ have indeed a complete white head, but you can easily see the difference with a blue opaline Agapornis fischeri: an opaline has no (violet) rump colour and much larger white / grey tail spots. Some of them also give the impression that there are some small dark spots on the wings (caused by a limited eumelaninereduction on the edge of the feathers).