Red Suffusion in the Turquoise Parakeet

Dominant Pigment Symbol: Rs Selection trait — approximate ~4 min read

Also written as: Rs Red-fronted Red-bellied

Quick summary

Red Suffusion adds red psittacofulvin pigment to the underparts. Red-fronted and Red-bellied are established varieties, but they are not mutations — multiple independent sources describe them as the product of decades of selective line-breeding, not of a single gene. How far the red spreads is decided by selection, not by how many copies of a gene a bird carries, so treat these percentages as the roughest in this calculator.

What is Red Suffusion?

Red Suffusion is a breeder-driven selection trait rather than one of the "classic" mutations documented at length across the wider parrot-keeping literature. This calculator models it as a dominant trait — visible whenever it is carried, with one copy and two copies looking alike, exactly like Grey — because no source says a one-copy bird and a two-copy bird differ in appearance. Copy number still shifts the odds for the next generation.

These are recognised varieties — but they are not separate genes. Red-fronted and Red-bellied are real, established names that breeders buy, sell and exhibit by. What they are not is two zygosity states of one mutation. This calculator previously listed Red-fronted as the single-factor form and Red-bellied as the double-factor form; no source supports that, and it has been removed. Stan Sindel, writing for the Avicultural Society of New South Wales, puts it bluntly — of "the red-fronted or orange bellied Turquoisine", he writes: "Again I must stress that these are not mutations… It is not genetical inheritance, it is just a colour variation brought about by selective breeding." Campagne (2008) files them together under Variations, and this project's own reference library lists them as aliases of one selection process.

So which bird has more red?

Not a question of which name you use — it is a question of how well the bird has been selected. Every source describes the same direction of travel: the red starts low, on the thighs and belly, and selection pushes it upward over generations toward the breast and throat. Sindel describes the red-fronted bird as one where "the orange belly has been extended up the throat". Campagne traces the identical progression — wild-caught birds carrying only a small red-orange patch low down, bred on until stock carried red across breast and belly, the spread differing from bird to bird (pp.122–123).

So low red is the baseline that essentially all these birds have; red climbing onto the breast and throat is the added coverage that marks a better bird. Benchmarks for a well-selected pair:

Ideal cock — bright red running from the throat right down to the lower belly and thighs, often with a more pronounced red shoulder patch and sometimes a red patch breaking into the yellow under the tail.
Hen — bright red across the belly and thighs only; the throat and breast stay clear of it.

This one is an approximation — read before trusting the numbers. Campagne (2008) does not treat Red-fronted and Red-bellied as a primary mutation at all. They appear under Variations (pp.122–123), described as a trait built up by selecting wild-caught birds that showed a red-orange belly patch and breeding on from them over generations — with the amount and intensity of red differing between individuals rather than falling into fixed classes. His wider discussion of selection attributes traits of this kind to a number of minor modifying genes that never become properly fixed in a line (pp.77–78) — in other words, likely polygenic.

Modeling that as one clean Mendelian locus is a deliberate simplification: it lets the calculator produce a number, but a real pairing will not respect tidy ratios the way a true single-gene mutation such as Dark Factor does. Expect a spread of red extent among chicks rather than discrete categories, and expect selection — picking your best-coloured birds to breed on — to matter more here than genotype bookkeeping. Whenever this trait is active, the calculator shows this caveat alongside the results.

How it works, in plain terms

Green and yellow areas of a Turquoise Parakeet's plumage get their color from psittacofulvin pigments (the same red/yellow/orange pigment family unique to parrots). Red Suffusion increases the proportion of the reddish end of that pigment family showing through, spreading a wash of red across areas that would normally read as green or yellow. How far that wash reaches varies from bird to bird — which is precisely why it responds to selection rather than behaving like a switch.

Red Suffusion + Opaline: adding Opaline to a Red Suffusion bird allows for maximal red coverage, extending the red wash from the throat to the lower belly. This calculator flags a "Maximal red coverage" badge on any offspring combining double-factor Opaline with at least single-factor Red Suffusion. One caveat: Campagne's species-specific passage says this "only happens in the best female specimens" (p.123), while the general chapter states it without any sex restriction (p.77). The badge currently ignores sex, which may overstate it for cocks.

Autosomal inheritance, explained

Red Suffusion sits on an ordinary autosome, so cocks and hens inherit it identically — there's no sex-linked complication.

Genotype → phenotype (as modeled here)

The table below is the simplified model the calculator uses. One copy and two copies are shown as looking alike — the source gives no basis for saying they differ, and the red extent you actually see is a matter of selection.

Why the dropdown only asks "present or not": for every other mutation the calculator lets you specify single or double factor, because you can establish that by looking at the bird or by test-mating it. Neither works here. Nothing visible separates a one-copy bird from a two-copy one, and because the red is shaped by selection and modifier genes rather than a single switch, test-mating does not cleanly resolve it either. Rather than invite a guess and then calculate on it as though it were fact, this trait offers presence or absence only, and is modeled as carrying one copy.

Genotype	Appearance	Applies to
Rs⁺ / Rs⁺	Normal	Cocks & hens
Rs⁺ / Rs	Red-fronted (single factor)	Cocks & hens
Rs / Rs	Red-fronted (double factor)	Cocks & hens

Both "Red-fronted" and "Red-bellied" — and "full red-fronted", which breeders also use for the most extensively coloured birds — are names applied to birds in the bottom two rows. None of them tells you a bird's factor count, and none is predictable from a pairing.

Sources & honesty note

The symbol, category and Opaline interaction rule for Red Suffusion in Neophema Pulchella come from this calculator's own compiled reference library, which also records Red-fronted and Red-bellied as aliases of a single selection process.

That this is not a Mendelian mutation is agreed on by several independent sources. Stan Sindel, "Mutations of Australian Parrots" (Avicultural Society of New South Wales, 1996) states directly that the red-fronted or orange-bellied Turquoisine is not a mutation and not genetical inheritance, but a colour variation produced by selective breeding. Dr Alain Campagne, A Guide to Neophema and Neopsephotus Genera and Their Mutations (ABK Publications, 2008), pp. 77–78 and 122–123, classes it as a variation rather than a primary mutation and notes the red varies between individuals. Australian and European breeder accounts describe the same history — line-breeding from wild-caught birds that showed small red patches on the thighs, carried on over many generations.

Because the calculator has to model something to produce a number, this trait is carried as a dominant locus with presence/absence input, and every result it appears in is flagged as approximate. Where the sources and the model disagree, the guide follows the sources. See the full references page for this project's other sources.