Red (split black) headed oddity

[SamDavis]

I have a number of just coloured young from a RH WB cock and a RH normal hen who have been together for a at least 3 seasons. Until now they have never produced any black head hens (from at least 20+ chicks). I'd assumed the cock to be double factor RH and I haven't had any black heads in my aviary for at least 5 or 6 years. But I was just catching some gouldians for a buyer and had a chance to closely check out all the hens from this pair in my holding aviary. Suprisingly there are a few that are black headed - no sign of any red feathers at all. This is strange as this pair has been breeding for at least 3 seasons, no other gouldians in with them and they've never thrown a black headed hen before.
Anyway just thought I'd share!

[Diane]

Just goes to show how random the percentage of genetics can be. Even with about a 25% chance of a BH its taken 5 + years for it to come out.

[natamambo]

BB, yes, theoretically, BH should be 25% of young. In fact theoretically, it's 50% of female young. A high proportion of male offspring (for whatever reason) will reduce the likelihood of black young though as there are less females to be BH overall.

Sam, the birds are all hens. If not then you've had a spontaneous mutation similar to the original one (whichever way around that was since we only speculate that black was the original, we can't prove it). That **may** mean that line is the forerunner of other genetic abnormalities (ie mutations).

[SamDavis]

Yes, the theoretical 25% BH hens is actually spot on this year (3 out of 12) from this pair. Unfortunately nobody seems to want BH hens so now that's all I've got left (plus the usual heap of b#$%dy cocks!)

[garyh]

You sound disappointed,most would be clapping hands,black heads are at a premium at the moment in vic well done at having bred so well,cheers garyh.