split

Since we will be discussing the orange breast zebrafinch (PO) in this article, it is certainly interesting to dwell a bit on the history of this mutation first.
The orange breast mutation (PO) is believed to have originated in Belgium. I consciously write "supposed" because the first orange breast (PO) was actually found at a bird merchant. In Dutch literature in particular, long before the discovery of the first orange breast (PO) in Belgium, zebra finches were described there with characteristics that we can now attribute to orange breast (PO) wearers.
What we are certain of anyway is that the honor of the discovery of the orange breast (PO) goes to a certain Mr. De C. who in 1978 noticed a rather special gray male in a store. This male had an orange breast bar when normally it should have been black. Mr. DE C. bought this copy, but at the breeding nothing came out of what he had hoped for. At the end of 1978, Paul CH., President of the BZC at that time, acquired this male. There were good and bad surprises with this subject, because unfortunately this male did not live very long. Fortunately Paul CH. had been able to get some young people before. Orange breast (PO) is inherited autosomal recessively compared to the wild form. The orange factor must therefore be doubly present to become visible. He therefore crossed young people between them and quickly took out the first orange breasts (PO).

Already the first orange breast breeder (PO) made the mistake of not combining and developing the orange breast (PO) with classic colors (gray, brown, pale back, masked) but he rushed directly on the combination of the orange breast with black breast (PN) and other mutations. From that moment on, every orange breast breeder’s dream was born to produce an all-orange zebra finch.
Due to having burned the breeding stage in the classic colors, the following question remained :

Are there any specific characteristics that we see in our classic orange breasts, are they just annoying derivatives of the presence of the black breast mutation (PN) or are these specific effects of the orange breast mutation ?

What do I mean by that? Often the orange chest gray or orange chest brown reveal not well defined cheeks. Likewise, there is often an orange hem on the fenders. Also, the chest frequently flows upwards and the belly shows patterns. All these observed characteristics are quite disturbing.

Small practical software allowing to have the probabilities of the results of a mating according to the mutation (s) of the respective parents. It can be put on USB sticks, no need for an internet connection to use it.

Before that, we will obviously need to know the genotype of each parent. To help you determine the mutation or combination of mutations to which your zebrafinch belong, you can refer to: Illustrated glossary of mutations in zebrafinch.
That said, I would say that this application is only an aid. The best thing will always be to understand how each mutation is transmitted. For this, I also advise you to have a good basis to consult the article: Zebrafinch genetics : Instructions.

Here is a site, also available in application, dedicated to the calculation of the genetics of zebrafinch. ZebraCalc allows you to have the probabilities of results depending on the mutations of the respective parents.

Before that, we will obviously need to know the genotype of each parent. To help you determine the mutation or combination of mutations to which your zebrafinch belong, you can refer to: Illustrated glossary of mutations in zebrafinch.
That said, I would say that this application is only an aid. The best thing will always be to understand how each mutation is transmitted. For this, I also advise you to have a good basis to consult the article: Zebrafinch genetics : Instructions.

1. Introduction

The breeding and competition of zebrafinch has grown considerably over the past fifteen years. In order to improve the size of the new mutations, breeders also have recourse to conventional "split" birds.
Some manage to combine several mutations. All this made it essential to know a minimum of applied genetics. It is this minimum that I would like to present to novice breeders.
This is not a complete course in genetics, but a simple presentation of the method I use preceded by some basics.

2. The zebrafinch and its mutations

A zebrafinch has a number of visible characters (size, shape, designs, color, sex) that constitute its phenotype. It can have, in addition to other unexpressed traits (it is said to be a split). The set of traits, expressed or not, is called the genotype.

A young zebrafinch grows out of an egg cell, the result of the fusion of the nucleus of a father's sperm and the nucleus of the female's egg. The bird's genetic program is already there: A series of cell divisions and coded information will (or not) trigger the appearance of the characters. The encoded information is carried by genes located on long filaments contained in the nucleus: chromosomes.
All chromosomes go in pairs: each chromosome therefore has its counterpart.

There are two categories of chromosomes :

- Sex chromosomes :
• XX in the male
• XY in the female

- Autosome chromosomes.

The gray zebrafinch living in Australia is the source of all of our farmed zebra finches. It has a whole set of genes distributed in its chromosomes.Whenever a new mutation has appeared, there has been a change in an original gene (and it has been shown to be hereditary). The original gene and the mutated gene are located in the same place called a locus on each of the homologous chromosomes.
Both genes are alleles.



A bird is pure (homozygous) when all of its alleles carry identical information.
A bird is heterozygous when at least one pair of alleles carries different information about the same trait.

We currently know about twenty different mutations of the gray zebrafinch.

The objective of this article is not to impose a management of breeding or create a controversy, but to share my experience of breeding, my observations as well as the difficulties I have encountered for about fifteen years of breeding zebrafinch in this combination of mutations.

The black breast is a mutation of design due to a different distribution of eumelanim in the plumage of the bird. The orange breast mutation is a color mutation: The eumelanin of the designs is transformed into brown orange phaeomelanin, which pulls towards the red-rust color for the best subjects. I do not think it is important to specify in detail how each mutation we already know alters on the mutated bird.

The ideal competition male, in addition to a correct shape and size such as a classic, must have no black discharge into the chest, must have a parotic zone (the color: between the beak and the cheek) white, a chest that rises as high as possible under the beak, a strong extension of the cheeks (the cheeks meet at the back of the skull) without running on the back (which for me represents a non-selective extension of the color), a gray back and not loaded with brown veil as is often the case, drawings on primary and secondary remiges (white+orange), the most intense red/rust color possible, the largest belly design (orange flames). To this it is necessary to add that the drawings of blanks must be marked with white ovals on orange background; The drawings of the tiles of tails are of course elongated.

The female as the male must be gray of back, shape and size correct, have a belly drawing (the flames)( note that this drawing is not orange as on the males but rather pulls towards the gray-brown), back drawings (on the outer edge of the remiges), a chest that rises very high, drawings of orange cheeks, flanks marked with dots and orange color also.

Should the female have the darkest possible cheeks and flanks ? I have no answer.
What is certain is that the first female orange breast had no orange cheeks and that the Dutch standard required females without cheeks a few years ago (now there are two standards accepted and judged differently: with drawing and without drawing…: type 1, type 2 in competitions). The female without drawn cheeks keeps the tail tiles as orange as possible. Most of my breeding females do not have cheeks, it is a character that I do not select specially.
I sometimes read on the internet that to release a good intensive male in color it is absolutely necessary a female with very orange cheeks, it is not true. We come out very good colored birds with females without cheeks if they are very grey. By “very grey” I mean birds whose eumelanin supersedes phaeo. This does not mean that certain characters should not be present (belly drawing, caudal overlying, eyelid etc.). I can say that the female without cheek has no influence on the intensity of the color on the males.



Some peculiarities are specific to the mutation combination

The orange breast seems to intensify the extension of the orange color of the drawings. We often observe subjects with a complete extension of the cheeks at the back of the skull, and this with a chest that goes up very high under the beak (compared with a pure black chest). This extension, when important, tends to color the color. I do not agree with those who say that orange-colored birds are black-faced birds. This coloration appears as well on black breast orange breast without the black face mutation for several generations.

I do not select the orange color of the color. Certainly it is a defect present in my birds but raising black face black breast orange breast, I do not pay attention to it.
In competitions, it depends a lot on the judges but in general, if the bird is good, they do not get heavily punished. Note that there are several kinds of orange colors, which a photo does not show well. Rusty orange colors like the chest and that come to blend with the cheek (not good) or an orange veil, lighter than the cheek and that stands out again (it goes better). But on big competitions, this is what the beautiful bird will miss to rank against the best.

The aim of this article is not to establish an unstoppable rule for the recognition of a gray male split (carrying) the black breast mutation. Rather, it aims to gather the clues that will allow you to identify it.
For this, every detail of the mutation is taken over, according to what I observed during the selection of my strain of gray black chest.

Before starting to analyze each possible clue, it seems important to me to bear in mind that the black chest mutation changes the shape of the drawings. To identify a split of the black chest mutation, I also advise you to take into account all the clues described in this article.

Let’s proceed and analyze the phenotype of a gray black breast from the head to the rectrices in comparison to a gray split the black breast mutation. To identify each descriptive term used, you can use this diagram : Descriptive terms in zebrafinch.

1. Mustachial line

Black chest : The moustachial line will be pronounced and intense black.
Split (/) Black chest : The moustachial line may be more pronounced than on a gray, however this does not constitute for me a sufficient clue.

2. Tear line

Black chest : The tear line disappears (ideally according to the standard) or only a fine line remains.



Split (/) black chest : Different cases depending on the force of expression of the mutation in the split.

- The tear line is present and fine :



- Tear line is present and wide :



- In some cases, the tear line of a split black chest may also be absent. It will be necessary to rely on the other clues to know if it is a split or a black breast in its own right.

3. Cheeks

Black chest : The drawing of the cheeks will extend up and back of the head.

I made this glossary to illustrate in photos the existing mutations in the zebrafinch.
He can help you identify the mutation (s) of your zebra finches.

Important precision :To identify the genotype of your zebrafinch, it will be necessary to take into account that a zebra finch can carry a mutation without being mutant.
Being a carrier (/, split) of a mutation means that it is partially present (genetically speaking). From the visual point of view the partially carried mutation will not be seen or only by some clues present in the appearance of the bird.
In this case, it will be necessary to have a trained eye to determine the genotype. Sometimes check couplings will be necessary.
Your zebra finch can also have several mutations, the possible combinations are numerous.

This glossary is based solely on the phenotype (visual characteristics) and single mutations (not combined).

Grey (GR)

The gray zebrafinch is not a mutation, it is the original (wild) type.



1. Gender-related mutations

The female can never be a split, so she is either mutant or non-mutant.
The male can be a split of the mutation.

Brown (Br)