Yellows and yellows?

[matcho]

Can someone please explain in the simplest terms the difference beyween an Australian Yellow Gould and a European Yellow? The reason being is that the breeder who I purchased my original stock from came and viewed my birds the other day. He made mention of Australian yellows and Euro yellows and indicated that I might have both in my stock. For the life of me I only identify my birds as yellow, normals, dilutes with the different chest and head colours. So who can tell me what is the diff between Euros and Aussies? He also had a look at my two chicks that are srangley marked and offered to tgo into a bit of a breeding/swap thing to try and see what comes out of the next generation. How cool is that?

[natamambo]

Apart from the genetics, there are some specific visual differences. I'll deal with the genetics second as identifying what you have determines what you do next.

* Aus Yellow (AY) cannot have a purple or lilac breast, so any yellow birds you have with non-white breasts are Euro Yellows (also called yellowbacks, YB).

* Pure yellow in the back Aus yellows are rare although some breeders are trying to breed out the splotches and so produce a "pure" bird colour wise so that may become harder to use in the future. Most have splotches of light green / dark yellow through the wing and back feathers. However, it is possible for them to be almost pure and while Euro yellows normally have an even olive tinge to the yellow over the whole back that can sometimes be a bit inconsistent. In general a WC Euro yellow will have no olive tinge at all, in fact it even disappears usually with a lilac breast.

So, how do you tell? Only by breeding unless it's obvious from the above. As the euro yellow is dominant *any* pairing with a normal bird will produce Some YB birds. If the cock is YB then all the cocks will be SF YB and all the hens will be YB, in this case the green back becomes pastelly and the black line around the head becomes blue. The presence of SF young in the clutch proves your bird is at least YB. If the hen is YB then all the cocks hatched must be SF.

The difficulty is, if yellow young appear you can't be certain that the partner isn't split AY. The clue is the SF young. If all the young are normals from a yellow / normal pair and you have both sexes in the nest then you do not have YB in that pairing you have AY.

As to the offer, I'd be hesitant to trust anyone with swapping out your birds in this generation. Do some in-house testing first. If you have a new mutation you want to keep control (and glory for yourself).

[matcho]

Nat,
Thanks for the reply, will have to read and read and read to try and make some sense. None of my yellow birds have coloured chests (purple or lilac) From what you say I have a fair few Aus yellows, some with only one or two of the slightest blotches on the back throught to an absolute sh.t load (read my 2 new chicks). In regards to the swapping thing, I think he would have more chance than me to make something of it as he breeds at least 10-15 prs at a time (but uses Bengos as fosters). He bred 80 this season, and according to him was a terrible year. Knowing my luck they would both go A over T with the first cool weather. Besides the swaps involve split blues. Besides, I'm not one for glory. How could I explain this to the mates at the pub whose biggest problem is if the beer runs out and they replace the barmaid with a barman?

[natamambo]

Meant to post these above, got distracted .

Aus yellows photos: http://users.skynet.be/fa398872/engoulm08.htm" onclick="window.open(this.href);return false;

Euro yellow SF photo http://users.skynet.be/fa398872/engoulm41.htm" onclick="window.open(this.href);return false; note the blue line around the head, this disappears in DF birds however it is very light compared to a PB SF bird.
and double factor: links to photos http://users.skynet.be/fa398872/engoulm44.htm" onclick="window.open(this.href);return false;