Dominant Grey budgerigar mutation
Encyclopedia
The Dominant Grey budgerigar mutation, often called the Australian Grey or simply Grey, is one of approximately 30 mutations affecting the colour of budgerigar
Budgerigar
The Budgerigar , also known as Common Pet Parakeet or Shell Parakeet informally nicknamed the budgie, is a small, long-tailed, seed-eating parrot, and the only species in the Australian genus Melopsittacus...

s. It is the basis of the Grey-Green and Grey standard varieties.

Appearance

The Dominant Grey mutation transforms the wild-type Light Green into the Grey-Green variety and the Skyblue into the Light Grey variety. The body colour of the Grey-Green is a dull mustard green and, compared to a Light Green, the mask is a slightly duller tone of yellow. The body colour of the Light Grey is an even, uniform, battle-ship grey.
In both the blue and green series birds the flights and long tail feathers are black. The pattern of black on the wing and tail markings is unchanged, but they are darkened to a jet black, resulting in high contrast between the black and yellow, which is particularly noticeable in the tail bar when the bird is in flight. The cheek patches are lilac-grey.
Variety Pantone Code
Light Green 375
Grey-Green 398
Skyblue 310
Grey 428


When combined with the Dark mutation
Dark budgerigar mutation
The Dark budgerigar mutation is one of approximately 30 mutations affecting the colour of budgerigars. It is part of the genetic constitution of the following recognised varieties: Dark Green and Olive in the green series and Cobalt, Mauve and Violet in the blue series.- Appearance :Budgerigars...

 the body colour of both Greys and Grey-Greens becomes slightly darker, but the effect is much smaller than the effect of the Dark mutation on Light Greens and Skyblues.

As this is a dominant mutation the colour changes described above apply to both single factor (SF) and double factor (DF) Greys and Grey-Greens. The only difference between SF and DF birds is in the colour of the afterfeather and shaft (see Feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...

) of the contour feathers. In the SF Light Grey these are the normal white but in the DF birds the afterfeather is dark grey, with a black shaft.

The World Budgerigar Organisation has established precise standards for budgerigar body colours using the Pantone
Pantone
Pantone Inc. is a corporation headquartered in Carlstadt, New Jersey, USA. The company is best known for its Pantone Matching System , a proprietary color space...

 Codes, as shown to the right.

Historical Notes

The earliest recorded appearance of the Dominant Grey mutation
was in 1934
, when Mrs S Harrison of Murrumbeena, Victoria, Australia, purchased a Grey cock from a dealer. The original breeder has not been identified. Early breeding results showed this Grey to be a Dark Grey (SF)/dilute
Dilute budgerigar mutation
The Dilute budgerigar mutation is one of approximately 30 mutations affecting the colour of budgerigars. It is one of the constituent mutations of several recognised varieties: the Light, Dark, Olive, Grey and Suffused Yellows and the Grey and Suffused Whites....

, and Mrs Harrison went on to establish a substantial strain of Greys from this bird.

In 1936, it was reported

that W F Shepherd of Kew, Victoria, also had Greys which he obtained from a colony breeder, and a Grey was also bred independently by R Hancock of Beverley, South Australia, in 1935.

Dominant Greys were first imported to Britain around 1937, one by Mrs R Brown of Morecambe for Mr Walter Higham, and one, from R Hancock's stock, by Tom Goodwin.

Genetics

The Dominant Grey allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...

 is dominant over its wild-type allele, so a bird possessing a single Dominant Grey allele (the heterozygote or single-factor Dominant Grey) is converted from the wild-type Light Green to Grey-green as described in Appearance above. That is, the presence of a single Dominant Grey allele is sufficient to permit the full expression of the mutation.

The double-factor Dominant Grey, with two Dominant Grey alleles, is identical in appearance to the single-factor Dominant Grey, although there is some evidence that the colour of the breast afterfeathers is changed from white to grey in the double-factor bird.

The Dominant Grey gene is located on one of the autosomal chromosomes. There is no known linkage of this gene with any other mutation.

External links

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