Genetics
What colour will the chicks be?
Pick the two birds by how they look — not by genotype — and this works out what they can produce, what they cannot, and why. Free, no account, and it runs entirely in your browser.
The calculator needs JavaScript. Everything below it — how the inheritance works and what each combination is called — is here either way.
ZW
Green-cheeks are ZW, not XY
Almost every mistake in a forum thread about conure colour comes from this one difference, so it is worth thirty seconds.
The male is ZZ, the female is ZW
The reverse of mammals. It is the mother who decides whether a chick is a son or a daughter, because she is the one with two different sex chromosomes to give.
Daughters take their sex-linked colour from their father, only
A daughter is her father’s Z plus her mother’s W. Her mother never gives her a Z at all. This is the least intuitive rule in bird genetics and the most useful one to know: a cinnamon father gives you cinnamon daughters, whatever the mother is.
A female cannot be “split” to cinnamon or yellow-sided
She has one Z. She either shows the colour or she does not carry it. A “split cinnamon hen” does not exist, and anyone selling one is guessing.
Turquoise and dilute work the ordinary way
They sit on ordinary chromosomes, so either parent can carry them hidden and it takes two copies to show.
Yellow-sided and cinnamon travel together
Both sit on the Z chromosome, so they tend to be inherited as a pair rather than independently. But they are not stuck together: they swap places about 32 % of the time, which is often enough that every combination shows up. The calculator uses that rate, so the percentages already account for it — there is no hidden “rare exception” category here.
That 32 % is measured in budgerigars, by Taylor and Warner in 1961 and confirmed since by a decade of test matings. No equivalent figure has been published for green-cheeks, so it is the best available estimate rather than a measurement of this species — and it is worth knowing that the widely repeated “1–3 %” belongs to a different pair of genes, cinnamon and ino, which sit much closer together.
Crossing-over in the sex chromosome of the male budgerigar — MUTAVI ↗
What each combination is called
Trade names are genuinely disputed between American and European breeders, and sources contradict each other. So every result here shows the trade name and the gene list together — nobody can argue with the second half.
| Trade name | Genes expressed |
|---|---|
| Normal (green) | — |
| Cinnamon | cinnamon |
| Yellow-sided | yellow-sided |
| Pineapple | cinnamon + yellow-sided |
| Turquoise | turquoise |
| Turquoise cinnamon | cinnamon + turquoise |
| Turquoise yellow-sided | yellow-sided + turquoise |
| Turquoise pineapple | cinnamon + yellow-sided + turquoise |
| American dilute | dilute |
| Mint | dilute + turquoise |
| Suncheek | cinnamon + dilute + yellow-sided |
| Cinnamint | cinnamon + dilute + turquoise |
| Moon cheek | cinnamon + dilute + yellow-sided + turquoise |
Three combinations have no trade name
These can come out of a pairing and nobody has settled on a word for them. The calculator prints the gene list alone rather than inventing one, because an invented name is the kind of mistake that spreads.
| Trade name | Genes expressed |
|---|---|
| no trade name | cinnamon + dilute |
| no trade name | dilute + yellow-sided |
| no trade name | dilute + yellow-sided + turquoise |
What this does not do
No misty, no ino
Misty is incompletely dominant — three states instead of two — and ino visually masks everything else. Both are rare and both would complicate the interface out of proportion to how often they come up.
No pied, no fallow, no European dilute variants
Breeders genuinely disagree about these and no calculator can arbitrate that.
It cannot tell you a bird’s sex
Green-cheek sex is not visible. A DNA test is the only way, and every result here that depends on sex says so.
It is arithmetic, not a guarantee
Percentages describe a very large number of chicks. A clutch of four can land anywhere.
Breeding is a health decision before it is a colour one. Nothing here is veterinary advice — see what that means in full.
Keeping the birds, not just breeding them
LunarKiri is a free care app for green-cheeks: a daily routine, a weight log that warns you when the trend turns, a sourced hazards directory and first aid.