I read alittle bit about it in my gouldian book: A guild to Gouldian Finches and their Muatations, and after having a look at my RH/WB/GB Cock it seems he has a red line. in the book it only really mentions Wild type gouldians having the fusion bar and that they are rare to find now in the domesticated viarity.
Does anyone have gouldians with the fusion bar and if so do their whitechest gouldians have it????
Jarryd
