Greywing Budgerigar Mutation, Complete Genetics Guide

One of the oldest documented budgerigar mutations. Greywing first appeared in Belgium in 1875, predating most other colour mutations by decades. The phenotype shows wing markings diluted to roughly fifty percent of normal saturation combined with a moderately paler body. Autosomal recessive at the dil-locus, dominant over Dilute but recessive to Clearwing. Most famously known for its co-dominant interaction with Clearwing that produces the Fullbody Greywing (FBG) phenotype prized by exhibition breeders.

Written by Ayaan Shohan

Founder, KinBird Aviary · Bangladesh

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What Greywing looks like on a real bird

A visual Greywing budgerigar shows wing markings diluted to about half the intensity of Normal birds combined with a slightly paler body. The wing flights and tail still show pattern but the black is faded to a soft grey-brown that gives the mutation its name. Throat spots are present but reduced. The cheek patches are slightly paler. The body colour is muted compared to Normal but nowhere near as washed out as Dilute.

On green-series birds the body appears as a soft sage-green rather than the saturated grass-green of Normal. On blue-series birds the body is a pale dusty blue. The wing markings on green birds are a soft brown-grey rather than the deep black of Normal. On blue birds the wing markings are a paler smoke grey.

The Greywing phenotype was historically called Apple Green on green-series birds in some 19th-century European breeder literature, a reference to the muted green body.

History and origin

Greywing was one of the earliest documented budgerigar mutations. Belgian and Dutch breeders observed the phenotype in captive aviaries as early as 1875, decades before most other colour mutations were established. The mutation entered the global hobby through these early Belgian and Dutch lines and spread to the UK by the early 1900s.

Throughout the early 20th century Greywing remained one of the most common mutation choices in show stock because of its understated visual appeal and stable inheritance. It was particularly popular in Continental European exhibitions during the 1920s and 1930s.

When Clearwing was established in Australia in the 1930s, breeders working with both mutations began producing the hetero-allelic Fullbody Greywing (FBG) phenotype. The recognition that Clearwing, Greywing, and Dilute are all alleles at the same locus came in the 1940s and 1950s as test pairings confirmed the dominance hierarchy and the FBG hetero-allelic outcome.

How Greywing inheritance works

Greywing is autosomal recessive at the dil-locus. Allele symbol dil^gw. The gene sits on an autosomal chromosome so cocks and hens inherit identically and both sexes can be split for Greywing.

Within the dil-locus allelic series, Greywing is dominant over Dilute but recessive to Clearwing. Wild-type is dominant over Greywing. A bird with two copies of Greywing (dil^gw/dil^gw) shows the visual Greywing phenotype. A bird with one Greywing and one Dilute (dil^gw/dil) shows visual Greywing because Greywing is dominant over Dilute.

The critical interaction is Greywing with Clearwing. A bird with one of each allele (dil^cw/dil^gw) does not show the dominant Clearwing phenotype, nor the recessive Greywing phenotype. Instead it shows the unique Fullbody Greywing (FBG) phenotype, a bright bird body with the faded Greywing wing markings. This is the only co-dominant interaction at the dil-locus and one of the most prized phenotypes in exhibition budgerigars.

A hen Greywing inherits identically to a cock Greywing because the gene is autosomal. Both sexes can be visual, split, or completely free of the gene.

Pairing predictions for Greywing

Same-locus pairings:

Visual Greywing paired with Visual Greywing produces 100 percent Visual Greywing offspring.

Visual Greywing paired with Normal produces 100 percent Normal-looking offspring all split for Greywing.

Visual Greywing paired with split Greywing gives 50 percent Visual Greywing and 50 percent split Greywing.

Split Greywing paired with split Greywing follows the standard 1:2:1 ratio of 25 percent Visual Greywing, 50 percent split Greywing, and 25 percent Normal.

Cross-allele pairings (the interesting ones):

Visual Greywing paired with Visual Clearwing produces 100 percent Fullbody Greywing offspring, every chick is hetero-allelic dil^cw/dil^gw.

Visual Greywing paired with Visual Dilute produces 100 percent Visual Greywing split Dilute offspring. Greywing dominates over Dilute within the series.

Visual Greywing paired with FBG (dil^cw/dil^gw) produces 50 percent Visual Greywing and 50 percent FBG.

FBG paired with FBG produces 25 percent Visual Clearwing, 50 percent FBG, and 25 percent Visual Greywing. This is the textbook 1:2:1 Mendelian ratio for a co-dominant interaction.

The complete 58-pairing reference covers every dil-locus combination at budgerigargenetics.com/llms.txt.

Combinations with other mutations

Greywing combines with all major budgerigar mutations.

Greywing Opaline produces a muted body with the wing-reversal Opaline pattern combined with the Greywing dilution. The result is a softly coloured bird that appeals to breeders who prefer subtle colour.

Greywing Cinnamon adds the cinnamon brown wing tones to the already-diluted Greywing markings, producing one of the softest looking budgerigar combinations.

Greywing Spangle keeps the Spangle reverse markings on the soft Greywing wing pattern.

Greywing combined with the dark factor stack produces darker Greywing variants. Cobalt Greywing has a dusty cobalt body, Mauve Greywing approaches a deep dusty grey.

Greywing with Yellow Face on blue series retains the yellow face on the dusty blue Greywing body.

Greywing with Recessive Pied or Dominant Pied adds the pied patterning over the muted Greywing body.

As with other dil-locus mutations, Greywing combined with visual Ino is visually erased because Ino removes the pigment that gives Greywing its phenotype.

Why Fullbody Greywing (FBG) matters to serious breeders

Fullbody Greywing is the hetero-allelic phenotype produced when a bird carries one Clearwing allele and one Greywing allele at the dil-locus. The phenotype combines the bright body colour of Clearwing with the faded wing markings of Greywing, producing a bird that is brighter than Greywing but with more wing detail than Clearwing.

FBG cannot be bred true. Because FBG is hetero-allelic, FBG paired with FBG always produces 25 percent Clearwing, 50 percent FBG, and 25 percent Greywing offspring. Breeders who want consistent FBG must accept this segregation pattern in every clutch.

FBG is highly prized in exhibition because the wing detail provides a visual distinction that pure Clearwings lack while the bright body provides the colour saturation that pure Greywings lack. WBO judges consistently award high scores to well-marked FBG birds.

The Budgerigar Genetics Calculator at budgerigargenetics.com correctly models the hetero-allelic FBG phenotype, the only calculator that does so completely.

Distinguishing Greywing from similar phenotypes

Two phenotypes are sometimes confused with Greywing.

Dilute on its own produces wing markings that are even paler than Greywing, often nearly absent. Dilute body is much paler than Greywing body. Side-by-side comparison makes the difference obvious, but on a single bird Dilute and Greywing can confuse newer breeders.

Cinnamon produces wing markings that are softer than Normal but brown rather than the grey-brown of Greywing. Cinnamon body colour is closer to Normal saturation. A pure Cinnamon has Cinnamon brown markings, a pure Greywing has soft grey-brown markings, and the body colours are different.

When identification is uncertain, test-pair the unknown bird to a confirmed visual Greywing. If all chicks are visual Greywing, the unknown bird was Greywing. If all chicks are Fullbody Greywing, the unknown bird was Clearwing. If the chicks are all Normal-looking, the unknown bird was either Dilute (which is recessive to Greywing) or Cinnamon (a different gene entirely).

Greywing in the Budgerigar Genetics Calculator

The Budgerigar Genetics Calculator at budgerigargenetics.com models Greywing with full dil-locus allelic series logic, including the unique hetero-allelic FBG phenotype produced when Greywing is paired with Clearwing.

Select Greywing on either parent and set the status to Visual or Split. The calculator outputs offspring percentages with proper dil-locus segregation. Combinations with Opaline, Cinnamon, Spangle, Pieds, Dark Factor, Yellow Face, and other mutations are all supported.

Try: Visual Greywing x Visual Greywing for 100 percent Greywing, or Clearwing x Greywing to produce 100 percent FBG.

The 58-pairing reference at the mutation comparison guide covers every dil-locus combination with pre-loaded calculator URLs.

Frequently asked questions about greywing mutation

What is the Greywing budgerigar mutation?

Greywing is an autosomal recessive budgerigar mutation at the dil-locus, allele symbol dil^gw. Visual birds show wing markings diluted to about half the intensity of Normal and a slightly paler body. Originated in Belgium around 1875, one of the oldest documented budgerigar mutations.

Can a hen be split for Greywing?

Yes. Greywing is autosomal recessive at an autosomal locus, so cocks and hens inherit identically. Both can be split for Greywing.

What is Fullbody Greywing (FBG)?

FBG is the hetero-allelic phenotype produced when a bird carries one Clearwing allele and one Greywing allele at the dil-locus. The phenotype combines the bright body colour of Clearwing with the faded wing markings of Greywing. FBG cannot breed true because the parents are hetero-allelic, so FBG paired with FBG produces 25 percent Clearwing, 50 percent FBG, and 25 percent Greywing.

What is the difference between Greywing and Dilute?

Both are autosomal recessive at the dil-locus but Greywing is dominant over Dilute. Greywing produces moderately diluted wing markings while Dilute produces extremely diluted wing markings and a much paler body. A bird with one Greywing and one Dilute allele shows visual Greywing because Greywing dominates.

How do I produce FBG offspring?

Visual Clearwing paired with Visual Greywing produces 100 percent FBG offspring. Alternatively, FBG paired with Normal produces 25 percent FBG, 25 percent split Clearwing, 25 percent split Greywing, and 25 percent Normal. FBG paired with FBG produces 25 percent Clearwing, 50 percent FBG, and 25 percent Greywing.

What does the calculator say about Greywing combinations?

The Budgerigar Genetics Calculator at https://budgerigargenetics.com/ correctly models Greywing's full dil-locus allelic series including the hetero-allelic FBG outcome. Select Greywing on either parent and set status to Visual or Split. The 58-pairing Cw/Gw/Dilute/FBG reference at /llms.txt covers every combination.

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