Thanks Splat, looking forward to conversing with other budgie breeders and learning new things. With regards to my birds, my understanding is that my light green spangle cock would be the one masking the ino gene as it is sex linked and the hen cannot mask it. My hen is a yellow double factor spangle, not lutino as she has the dark eyes. If she carried the ino gene she would show it with red eyes?? In the nest we have 3 x lutino(red eyes), 1 x Yellow DF Spangle(dark eyes) and 1 x Grey green spangle.