Coturnix Color Genetics: A Plain-English Breeder's Guide

Coturnix colour genetics look intimidating and are mostly three ideas repeated. Once you can tell a recessive from a dominant from a sex-linked trait, you can predict most pairings on the back of an envelope — and understand why the ones that surprised you did what they did.

One honest caveat first, and it matters: Coturnix colour genetics are still debated, and inheritance varies between lines. The modes below are what breeders commonly report, not settled science with a gene map behind every colour. Verify against your own stock before you bet a season on a prediction.

The three modes, in plain English

Every bird carries two copies of each gene, one from each parent.

• Recessive — the trait only appears when a bird has two copies. One copy makes a "carrier" that looks completely normal. This is why a recessive colour can vanish for a generation and reappear from two ordinary-looking parents. Tuxedo, English White, Roux and Range are usually reported as recessive.
• Dominant — one copy is enough to show the trait. A dominant colour cannot hide: if the bird does not show it, it does not carry it. Rosetta and Tibetan are usually reported as dominant.
• Sex-linked — the gene sits on the Z sex chromosome. In birds (unlike mammals) males are ZZ and females are ZW, so a hen has only one copy and shows whatever that single copy carries. This is why sons and daughters from the same pairing can differ predictably — and why a sex-linked cross lets you tell chicks apart at hatch.

The mutations you will actually meet

• Pharaoh — wild type. The brown base everything else is measured against.
• Italian (Golden) — dominant, often incomplete. Homozygous birds are frequently pale or weak, and some breeders report outright lethality.
• Tibetan — dominant, darker. Homozygous lethality is also reported by some breeders.
• Tuxedo — recessive. White bib and belly patterning.
• English White — recessive. White plumage, and it can hide colour underneath.
• Roux (Fawn) — recessive. Reddish-fawn dilution.
• Rosetta — dominant. Frequently combined with other colours.
• Range / Dotted White — recessive. White with coloured flecks.
• Celadon — recessive, and not a plumage colour at all. It affects egg shell colour, producing the blue eggs. A celadon bird can be any plumage colour; two carriers can produce blue-egg layers from brown-egg parents.

Individual colour pages with photos live in the Coturnix variety guide — including Pharaoh, Italian, Tuxedo, English White, Roux, Rosetta, Tibetan and Celadon.

The homozygous-lethal problem

This one costs people whole hatches, so it is worth understanding.

When a dominant colour is homozygous-lethal, a bird carrying two copies dies — usually in the egg. Breed two of that colour together and roughly a quarter of the eggs simply never hatch, while the chicks that do hatch are two-thirds coloured and one-third wild type. Everything looks like an incubation failure. It is not.

The fix is simple once you know: pair a lethal-gene colour to a wild-type or non-carrier bird rather than to another of the same colour. You get half coloured chicks and a full hatch, instead of two-thirds coloured chicks and a graveyard.

If you are hatching a suspiciously consistent quarter of dead-in-shell eggs from a coloured pair, check the pairing before you start rebuilding the incubator. (The other causes are covered in the hatch-rate guide.)

Predicting a pairing

The three cases you need, without any algebra:

• Recessive × recessive (both birds show the colour): all chicks show it. This is how a colour line breeds true.
• Carrier × carrier (neither bird shows it): about a quarter show the colour, half are carriers, a quarter are clean. This is the classic "where did that come from?" hatch.
• Shows it × clean: no chicks show the colour, but every chick carries it. Breed those offspring together and the colour reappears in the next generation.

For dominants, one showing parent gives roughly half showing chicks — unless that parent has two copies, in which case all chicks show it (and the lethal caveat above applies).

Working several traits at once — a tuxedo pattern on a roux base carrying celadon, say — is where hand arithmetic gets unpleasant. That is what the colour-genetics calculator inside Quail Keeper Max is for: pick the trait, set the inheritance mode, flag homozygous-lethal where it applies, and it returns the expected ratios for the pairing, including sex-linked splits between sons and daughters.

Why the record matters more than the theory

Genetics tells you what a pairing should produce. Your records tell you what it did — and with Coturnix, where lines differ and inheritance is contested, the second is worth more than the first.

Band your birds, record which pen produced which chicks, and note what actually hatched. After two or three generations you will know how your line behaves, which is the only genetics that pays you.

Quail Keeper Max keeps the pedigree and the colour calculator in one place — lineage by band ID, hatch results by pen, and predicted-versus-actual for each pairing. Start free for 14 days and stop rebuilding your colour project from memory every spring.