Aussie Finch Forum

Nice explanation, Danny; and great analogy.

mattymeischke wrote:Nice explanation, Danny; and great analogy.

Agree. Or if the inheritance/genetics is just too complex to comprehend then just use the white paint - instant pied!

Danny
What happens if you continually breed Brother to Sister, Father to Daughter etc.

E Orix wrote:Danny
What happens if you continually breed Brother to Sister, Father to Daughter etc.

Same as usual - weakened lines, infertility, posibility of new mutations emerging.

For those interested, I can email you the less simplistic version of the pied peafowl genetics

E Orix wrote:I won't argue on genetics but the bird with the white dot is to me either a normal bird or a set mutation but I can't accept that
It's a split. Unless someone can put up a real good explanation designed for dummies.

I believe you are correct in your assumption that if it has a white dot [Feather] and isn’t a normal or what is accepted as normal by classification, and then it must be a set colour mutation. The classification for this colour mutation containing white feathers is pied.
“The Pied Mutation is recessive, though splits may sometimes be discernible from white tick marks, mostly appearing on the throat and wing edges.” http://www.javasparrow.org/pages/java_s ... lours.html

Basically in Java Sparrows the wild type Blue-Grey or native colouration is often called “normal”.
A “Pure Java Sparrow” is described as meaning an individual finch that has the appearance of a wild Java sparrow (without any white feathers at all) and it should not be “split” (contain any other colour variation in its genetics/bloodlines). Meaning it should always breed true to its colour. However, this is where the problem begins with breeding Java Sparrows, since it is possible to have a finch with the visual appearance (phenotype) of a normal, because the wild type Blue-Grey colour is dominant. Dominant colour will mask/hide other genetic colour codes that are recessive. A recessive colour is one that is carried in the finches’ genetic makeup (genotype) and not always externally visible. Most colour mutations I know of in Java Sparrows are recessive however, the recessive colour mutations can be concealed by the dominant visual colour (in Java Sparrows it’s the wild type Blue-Grey or native colouration). See the problem arising!

For example; if I paired and bred a “pure” wild type Blue-Grey with a pied the offspring will all be visually Blue-Grey (normal) because the dominant colour genetics overrides or dominates however, all of the offspring from the above pairing are visually normal (due to the dominance of the normal colour genetics), resulting in each of the offspring being split for pied, carrying the genetic coding for the pied mutation
It’s not until the paring of the offspring with another finch split for Pied that split (recessive genetic colour coding), reveals itself. Some of the pied offspring resulting from this breeding may only contain a single white feather. Therefore not being a true Blue-Grey (normal) BUT … by definition and genetics, it’s a Pied.
Genotype–phenotype distinction is in genetics.
"Genotype" is an organism's [in this case a finch] full hereditary information. This is the "internally coded, inheritable information
"Phenotype" is an organism's actual observed properties [in this case its visible feather colouration], the "outward, physical manifestation” such as morphology, development, or behaviour. This distinction is fundamental in the study of inheritance of traits and their evolution
http://en.wikipedia.org/wiki/Genotype-p ... istinction

garymc wrote:Can remember as a kid (many moons ago, probably before our stocks were proliferated with the various mutations), the guy around the corner kept and bred normal javas. When he sold them he used to sex them by the white under the chin - whilst this was probably (or just plain wrong) wrong, it does indicate that the white spot under the chin was present long before our stocks were "tainted" for want of a better word.

I have never heard of this before and to my knowledge white under the chin is not sex-linked. I suspect he was probably looking at the shape of the lower mandible, as many breeders believe they can see a slight 'V' in the hen and a more rounded 'V' tending toward a 'letter 'U shape in the cock. The experienced have an almost perfect score regarding sexing. NOT ME... I personally need several birds to view before I would make a sex determination for a Java and still with no certainty. DNA is my only certain way or I often use the cheaper and slower method of observing cocks crowing, as is common in all Lonchura species, still not 100% as some cocks are much slow to start crowing or just shy.

As a parrot breeder there are two birds that come up as those that show they carry the pied genetics. The cockatiel and rainbow lorikeet. Cockatiels that are split to pied carry yellow feathers to the back of their neck and rainbow lorikeets are class as single or double factor pieds. Those that are single factor pieds are commonly called streaky heads and show red feathers through their blue head. Both when bred are the standard for breeding pieds, eg two splits gives 1 in 4 pieds, two pieds give pure pieds and pied to split give half pied. I do not keep or breed java but they COULD follow on from these and show a difference from normal birds.
Rich