Frequently Asked Questions

A split bird carries one copy of a recessive mutation but does not show it. It looks completely normal, yet can pass that mutation to its chicks. Splits are written as “split Cinnamon”, “split Dilute”, and so on. Only recessive mutations have a split state — dominant and incomplete-dominant mutations like Grey and Dark Factor are always visible if the bird carries them.

Parrots use a Z/W sex chromosome system: cocks are ZZ and hens are ZW. Cinnamon, Opaline and Ino all sit on the Z chromosome. A cock has two Z chromosomes, so he can carry one mutant copy invisibly. A hen has only one Z, so whatever is on it is what she shows — there is no second copy to hide behind. A hen is therefore either wild-type or visual, never split, for these three.

They are the sex chromosomes. In birds the system is the reverse of mammals: the cock is ZZ (the matching pair) and the hen is ZW. This is why sex-linked mutations behave so differently in each sex, and why a hen’s single Z always comes from her father.

Almost certainly not. These are probabilities per chick, not quotas for a clutch. A 25% outcome means each individual chick has a one-in-four chance — exactly like coin flips, a run of four can easily produce none of them, or all four. The percentages describe the odds, not a guaranteed distribution. Small clutches routinely look nothing like the predicted split.

Cinnamon and Opaline are both on the Z chromosome and sit physically close together, so they tend to be inherited as a pair far more often than independent genes would be. This calculator assumes independent assortment — the standard simplifying assumption — so when both are in play, real clutches can skew noticeably from the calculated odds because of crossover linkage. The warning is there so you know the numbers are an approximation in that specific case.

They are two different loci. Dun Fallow (df) is a red-eyed fallow-family mutation; Faded (fe) is tracked separately and is not noted as red-eyed in this project’s reference material.

In Neophema pulchella the old nickname “Isabel” refers to Faded — Campagne (2008) heads the Turquoisine section “Faded (Isabel)”. An earlier version of this calculator also attached that name to Dun Fallow; that was incorrect for this species and has been corrected. Be aware too that whether the Turquoise Parakeet has a distinct mutation properly called Dun Fallow is itself unsettled — the same source documents only European and Australian Fallow types in its Turquoisine chapter.

Grey is a simple dominant mutation, so one copy (single factor) and two copies (double factor) look identical — both are Greygreen. The difference is only in what they pass on. A single-factor bird passes Grey to about half its chicks; a double-factor bird passes it to every chick. Select Double Factor only if the bird has been proven through test breeding, since you cannot tell the two apart by eye.

Not yet. This calculator currently covers Neophema pulchella (the Turquoise Parakeet) only. Other species in the genus — Elegant, Blue-winged, Scarlet-chested (splendida), Rock and Bourke’s — share some mutation names but differ in which mutations exist and how they are documented, so applying these results to them would be unreliable.

The inheritance rules follow standard Mendelian and Z/W sex-linked genetics, and the mutation roster is compiled from published Neophema references. Wherever a visual description is extrapolated from cross-species parrot genetics rather than verified against Neophema-specific sources, the relevant guide page says so explicitly. See the references and credits for the full source list.

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