The Opaline budgerigar mutation is one of approximately 30 mutations affecting the colour or appearance of budgerigars. It is the underlying mutation of the Opaline variety. When combined with the Yellowface II and Clearwing mutations the Rainbow variety is produced.

Appearance

The Opaline mutation is characterised by several features which are invariably present, although many show variations in the intensity of their expression. The most obvious effect is on the striations which extend from the top of the head down the neck to between the wings in the non-Opaline. In the Opaline these striations are very much reduced in intensity, being almost absent in many individuals, particularly in small birds of yellow (as opposed to buff) feather. The cap of the Opaline extends further back over the top of the head, gradually merging into an area the same colour as the body which continues down the back of the head to form a 'V' shape between the wings. The intensity of the striations in this area is variable, but in the original mutations, particularly the Australian, the 'V' was very clear.

In the non-Opaline the wings show dark grey or black markings over a yellow or white ground, but in the Opaline the ends of the barbs of the wing coverts assume the same colour as the body, rather than the ground colour. This suffusion of body colour in the wings produces the opalescent effect which gave the mustation its name. The area of black pigmentation in each feather is reduced and in the original specimens the wing butts were particularly devoid of black pigment, resulting in a clear area often called the 'thumb-print'. These thumb-prints appear to be associated with a clear 'V', but are now seen less often, since the Budgerigar Standard calls for normal wing markings in the Opaline.

The flight feathers of the budgerigar consist of 10 primaries and 10 secondaries. These are dark grey with a clear central band across every feather from the 2nd primary to the 8th secondary. These clear areas are not visible in the folded wing, but form a prominent continuous band running right along the wing when it is stretched out. It is hidden from above by the coverts but is visible from beneath. In the Opaline this clear band is present on every flight feather and is much broader. Only the distal half of the flight feather is dark, with the clear zone extending from the mid-point to the shaft. Because it is broader it is visible in the primaries of the folded wing of the Opaline, just beneath the secondaries and primary wing coverts, as a small clear patch.

A similar effect occurs in all the wing feathers, most noticeably in the primary and secondary wing coverts, and also in the six tail feathers, which carry a similar clear band on feathers 2 to 6 in the non-Opaline. The first (longest) tail feather of the Opaline also carries a rather blotchy clear area of somewhat variable extent, and the suffusion of body colour present to a small degree in the non-Opaline is intensified in the Opaline.

Most Opalines show a brighter body colour than the corresponding non-Opaline, paricularly in nest feather and particularly in the rump area. This is due to a reduction in the melanin content of the barbules of the contour feathers.

The final characteristic of the Opaline (and the Cinnamon) is the colour of the down feathers of the young nestling. These are white instead of the usual grey, and this allows Opalines to be identified at a very early age.

The Ino budgerigar mutation is one of approximately 30 mutations affecting the colour of budgerigars. It is the underlying mutation of the Albino and Lutino varieties and, with Cinnamon, a constituent mutation of the Lacewing variety.

Appearance

In the green series the Ino is known as the Lutino, with pure yellow contour feathers, white or pale yellow flight feathers and tail feathers and silvery-white cheek patches. In some lights the body can show a very pale green sheen.

In the blue series the Ino is known as the Albino, and is pure white throughout. The cheek patches are almost the same colour as the body, but slightly more silvery. In some lights the body can show a very pale blue sheen.

The eyes of both the Lutino and Albino are red at all ages with white irides when adult, the beak is orange and the feet and legs are pink. The cere of an adult Ino cock is greyish-purple rather than blue.

The World Budgerigar Organisation has established precise standards for some budgerigar body colours using the Pantone Codes, as shown to the right for the Lutino.

The Ino mutation also induced changes in the nestling. The down is white rather than grey and appears only sparsely, never growing down the centre of the back. As the feathers appear, those down the spine and along the ventral centre line are late to develop.

The Ino gene masks the effect of virtually all other mutations, including Opaline, Dark, Dominant Grey, Dilute, and Clearwing. These genes, when present in an Ino in either heterozygous or homozygous form, cause no change in the appearance of the Ino. But the Ino gene does not entirely mask Cinnamon. A Cinnamon Ino, usually called a Lacewing, has pale brown or fawn spots, tail and wing markings. These markings are quite clear, but considerably fainter than the markings of a normal Cinnamon.

The Dark-eyed Clear has a similar body colour to the Ino, but has solid reddish-purple eyes without a white iris.

Cinnamon Dilute German Fallows, NSL Inos and Inos are all very similar and difficult to distinguish from each other, but the first two are so uncommon difficulties arise rarely in practice.

Albino hen

Historical notes

The first known reference to the Ino mutation in the budgerigar was a report by Mr L van der Snickt, a Belgian fancier, in the German avicultural paper Die Gefiederte Welt (The Feathered World) in 1879. He wrote that he had seen that year nine Lutinos, all hens. (In fact, he called them Albinos, since the name Lutino did not then exist, but from his description and the fact that the Blue mutation was not established until the 1880s it is clear they were Lutinos.) One breeder of these birds was Mr Kessels, also of Belgium, who in 1881 bred 25 Lutinos, all hens.

A coloured picture of a Lutino appeared in the Brussels journal, Acclimatation Illustrée, in 1882, and it is thought they were being bred in Holland around 1885, while in England Mr C P Arthur of Melksham in Wiltshire bred what he believed was a pair of Inos around 1887. After the 1880s no mention seems to have been made in the press of Inos until the 1930s, when interest in budgerigar mutations suddenly increased.

In 1930/31, Lutino hens were owned by both Capt H S Stokes of Longdon, near Rugeley in Staffordshire, and Mrs Huntington of Warwick. In August 1932 Mr F J Mullis of Horsham, Sussex, bred an Albino hen. None of these led to an established strain.

In September 1931, Mr E Böhm of Bawerk in Germany bred, as the last of nine young from a pair of Cobalt split Dilutes, a snow-white red-eyed hen - the first recorded Albino. Almost exactly a year later, on 12 September 1932, a second Albino hen was bred by Mr Fischer of Honow in Germany from a pair of Skyblues. Both of these strains were established by the original breeders and also by others who acquired early stock from them, in particular by Kurt Kokemüller of Arnum über Hanover, and Mr Schrapel, also of Hanover, who performed together the first genetic investigations into the Ino mutation and published the first correct pairing expectations in the German publication Der Wellensittich (The Budgerigar) in November and December 1933.

A third appearance of the Ino mutation occurred in Germany around 1933, when Mr Kuhlewein bred a Lutino hen in an uncontrolled breeding flight. This strain was also established.

Albino hen and Lutino cock

Other Ino mutations also appeared in Europe in the early 1930s, and several British fanciers, including Walter Higham, Scott and Camplin, and Tod Boyd, had imported continental Lutinos by the mid-1930s. Some of these turned out to be of the non-sex-linked type and the unwitting mixing of the two mutations led to considerable confusion. All British Inos seem to have descended from these imported continental Inos.

In 1976, Dr T Daniels began a controlled programme of pairings to produce a Cinnamon Ino by deliberately crossing Cinnamons to Inos, and to estimate the cross-over value between these two mutations. The first Cinnamon Ino was produced in late 1979 and was identical in appearance to a Lacewing.

Genetics

The Ino mutation is a sex-linked recessive at the ino locus on the X chromosome. The wild-type genetic symbol is ino⁺ and the ino mutant allele has the symbol ino. Its effect is to inhibit the production of the melanin pigment which is normally present in all feather barbs in either the medullary or cortical cells or both. The presence of black melanin pigment in the cortex of the barbs is necessary for the production of the black markings and in the medulla of barbs for the production of the blue colouration (which combines with the yellow pigment in birds of the green series to produce the green colouration), so this mutation removes all black and blue colourations resulting in a white bird in the blue series and a yellow bird in the green series.

Because the Ino mutation totally inhibits the production of normal melanin pigment it prevents the visible expression of all the other mutations which depend on the presence of melanin to show their effect. This is called epistasis, and Ino is phenotypically epistatic over many other mutations, including Dark, Grey, Opaline, and the Dilute series. It is not epistatic over the Blue mutation, so there are two forms of the albino budgerigar, one in the green series called the Lutino and one in the blue series called the Albino. Both these varieties may be masking many other hypostatic mutations, so the genotype of an Albino or Lutino with respect to these mutations cannot be determined visually. Nor is the Ino mutation epistatic over the Cinnamon mutation

In birds, the cock has two X chromosomes and the hen has one X and one Y chromosome. So in hens whichever allele is present on the single X chromosome is fully expressed in the phenotype. Hens cannot be split for Ino (or any other sex-linked mutation). In cocks, because Ino is recessive, the Ino allele must be present on both X chromosomes (homozygous) to be expressed in the phenotype. Cocks which are heterozygous for Ino are identical to the corresponding Normal. Such birds are said to be split for Ino, usually written '/ino'.

The table on the right shows the appearance of all possible genetic combinations involving just the Ino mutation.

The Ino mutation does not mask the Cinnamon mutation, these two genes being neither fully epistatic nor hypostatic to each other. When combined in doubly homozygous form (cin-ino/cin-ino in cocks or cin-ino/Y in hens) the Lacewing phenotype is produced. The Cinnamon markings are clearly visible, although considerably fainter than in a normal Cinnamon. For many years the Lacewing was thought by many to be a separate mutation but it was demonstrated in 1979 that it was simply a Cinnamon Ino when a Lacewing was deliberately produced by combining separate Cinnamon and Ino genes. Once brought together, these two genes are almost always inherited together due to the close linkage between them, giving the impression of being a single gene.

The Ino mutation is a member of a series of multiple alleles at the ino locus. Only one other member is known -- the Sex-linked Clearbody mutation. For details of the genetic relationship, see the Genetics section in the Sex-linked Clearbody article.

The Ino gene is linked to other genes located on the X chromosome, i.e. to the genes of other sex-linked mutations. In addition to the Cinnamon mutation, these mutations include Opaline and Slate. The cross-over or recombination values between Ino and these linked genes has not been measured accurately, but some approximate measurements of the cross-over values have been made:

Albino cock

• Cinnamon-Ino COV: Breeding results collected by C Warner and T Daniels found just 1 crossover in 36 between Cinnamon and Ino. Other measurements found at least 1 cross-over in 18, so combining these the best estimate of the recombination value is ≥4±3%.

• Opaline-Ino COV: Only one direct measurement of the Opaline-Ino linkage has been reported. This found 3 cross-overs in 10, giving a recombination value of 30±17%. But since the ino locus is very close to the cinnamon locus the COV for Opaline-Ino must be very similar to that for Opaline-Cinnamon. The Opaline-Cinnamon linkage has been measured to be approximately 36±6% (see Genetics in Opaline budgerigar mutation), so these two results are in agreement within the limited statistics.

Cocks split for both Cinnamon and Ino have one Cinnamon allele and one Ino allele together with one each of the corresponding wild-type alleles. The linkage between the Cinnamon and Ino genes gives rise to two types of split cinnamon-ino cocks, both visually identical.

• Type I split cinnamon-ino cocks are bred by mating Cinnamon-Inos (Lacewings) to Normals and have the two mutant alleles on the same chromatid, symbolised as cin⁺-ino⁺/cin-ino. Geneticists call this 'coupling' rather than 'Type I'. Because of the linkage, the Cinnamon and Ino alleles from Type I cocks tend to be inherited together in their progeny. When mated to Normal hens, Type I cocks produce predominantly Cinnamon-Ino (Lacewing) and Normal hens, with Cinnamon and Ino hens resulting extremely rarely from a cross-over. Roughly 48% of the hens will be Cinnamon-Ino (Lacewing), 48% Normal, 2% Cinnamon and 2% Ino.

• Type II split cinnamon-ino cocks are bred by mating Cinnamons to Inos and have the Cinnamon and Ino mutant alleles on opposite chromatids, symbolised as cin⁺-ino/cin-ino⁺. Geneticists call this 'repulsion' rather than 'Type II'. Because of the separation, the Cinnamon and Ino alleles from Type II birds tend to be inherited separately in their progeny. When mated to Normal hens, Type II cocks produce predominantly Cinnamon and Ino hens, with Cinnamon-Ino (Lacewing) and Normal hens resulting extremely rarely from cross-overs. Roughly 48% of the hens will be Cinnamon, 48% Ino, 2% Cinnamon-Opaline (Lacewing) and 2% Normal.

Hens cannot be split for any sex-linked gene, so only cocks exist in Type I and Type II form.

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The Cinnamon budgerigar mutation is one of approximately 30 mutations affecting the colour of budgerigars. It is the underlying mutation of the Cinnamon variety and, with Ino, a constituent mutation of the Lacewing variety.

Appearance

All the markings which appear black or dark grey in the corresponding Normal appear brown in the Cinnamon, of a shade similar to that of white coffee. The Cinnamon markings on cocks tend to be considerably darker than on hens. The long tail feathers are lighter than Normals. The body color and cheek patches are much paler, being about half the depth of colour of the Normal. The feathers of Cinnamons appear tighter than Normals, giving a silky appearance. It is these quiet pastel shades and the sleekness of the plumage that give the variety its appeal.

The eyes of the newly-hatched Cinnamon are not black like the eyes of Normals, but deep plum-coloured. This colour can be seen through the skin before the eyes open, and immediately after opening a reddish-brown gleam can be seen. A few days later the eye darkens and is then barely distinguishable from the that of a Normal chick, but by this time the difference in down colour is visible: Normal chicks have grey down, but Cinnamon (and Opaline and Ino) chicks have white.

The skin of Cinnamon chicks is also redder than than Normal's, and this persists into adulthood: the feet of Cinnamons are always pink rather than bluey-grey. The beak tends to be more orange in colour.

Superficially, the Cinnamon is very like the two types of Fallow, the German Fallow and the English Fallow, but the eye of the Cinnamon is the usual black with white iris (except for the first few days after hatching, when it is purplish or plum-coloured) whereas the eyes of both varieties of Fallow are red at all ages. The body colour of the Cinnamon is also a rather deeper shade of green or blue than that of the Fallows.

Historical Notes

Cinnamon specimens of many species have been observed in the wild. A stuffed Cinnamon Light Green budgerigar hen owned by Mrs Ellis of Cottenham, Cambridgeshire, in 1935 and said then to be at least 50 years old was thought by Cyril Rogers to be wild-caught when he examined it.

The first Cinnamon to be reported in Britain was a Cinnamon White Blue hen bred in 1931 from a pair of Light Green split blues by Miss M E J Hughes and her brother Mr G N Hughes of Hampton Hill, Middlesex. This bird was exhibited in 1931 and 1932, although not described as a Cinnamon as that name had not then been adopted. The mutant hen and its sire died without further issue. Mr I J J Symes gave a description of what he called "the brown factor" in this bird, saying the wing markings varied from raw umber to burnt sienna.

Mr A D Simms, of Potter's Bar, also in Middlesex at the time, paired together several Dark Green split greywing siblings in 1931 bred from an Olive cock and a Greywing Light Green hen. Among other, eight Greywing Greens, all hens, were bred which showed a "rather peculiar colour in their nest feathers". These hens were probably Cinnamons or Greywing Cinnamons, but as the Cinnamon variety was not known at the time they were regarded as slightly strange Greywings.

Mr G F Porter of Codicote, near Hitchin, in Hertfordshire, obtained a pair of Dark Green split greywings from Mr Simms, and he too bred what he called Greywing Green hens. One of these he paired to a Cobalt split dilute cock and this pairing produced, among other progeny, a Cobalt cock which was later found to be split for Cinnamon and Dilute. This cock, paired to a Dark Yellow split blue hen, bred a Cinnamon Skyblue hen in early 1933. Other pairings of descendents from Mr Simms' Dark Green split greywings produced a Cinnamon Olive and a Cinnamon Cobalt for Mr Porter, also in 1933. Towards the end on 1933 M Porter bred a Dark Green Cinnamon cock—the first Cinnamon cock to appear in Britain.

Mrs A Collier of Luton also bred two Cinnamon hens in 1933, a Mauve and an Olive, but as these were both from stock obtained from Mr Porter, these were almost certainly the same mutation. Mrs Collier was the first to report the characteristic plum-coloured eyes of the very young Cinnamon chick, perhaps being prompted to look for this as it was already a known characteristic of the Cinnamon Canary.

Further Cinnamons appeared in 1933 in the aviaries of Mr G Hepburn of Peterhead, Aberdeenshire. These Cinnamons were bred from a pair of Light Greens obtained from a dealer in Aberdeen, but the ring on the cock showed it came from a Mr Banham, who lived near Victoria Station in London. Mr Hepburn attempted to trace the origin of his birds but was unable to establish a firm link to Mr Simms' birds. Nevertheless, all three Cinnamon mutations, those of Messrs Hughes, Simms and Hepburn, originated within a circle of 15 miles radius and within two years of each other. This strongly suggests the importation of a single Cinnamon carrier cock into the Middlesex area around 1930.

Mr S E Terrill reported that the first Australian Cinnamon appeared about August, 1931, near Adelaide. In 1934 Mr Terrill said he had "four or five cock Cinnamons of two, probably three, generations and about 36 Cinnamon hens of at least three generations." Mr Schumacher, of Magdeburg, Germany, also bred budgerigars with brown wings in 1932, but he disposed of them the year after and it is not known if these were Cinnamons.

Towards the end of 1934 the Budgerigar Society recognised the Cinnamon variety for exhibition purposes and published its show standard.

The Violet budgerigar mutation is one of approximately 30 mutations affecting the colour of budgerigars. It is one of the constituent mutations of the Violet variety.

Appearance

The Violet factor produces a visual effect in any bird which carries it. The effect depends on whether the Violet factor is single or double, and whether the Dark and Blue mutations are present. In total there are 18 visually different combinations of these three mutations. However, only three of these approximate to the colour specified by the Visual Violet exhibition standard.

The World Budgerigar Organisation has established precise standards for some budgerigar body colours using the Pantone Codes. The colours of the recognised blue series varieties, including Visual Violet, are shown on the right.

Green series

SF Violet Light Greens have contour features similar in shade to a Dark Green, but the faint ribbing present in the body feathers of a Dark Green is lacking, giving the feathers of the Violet Light Green a more satin-like finish. The tail feathers are paler than the navy blue of the Dark Green, rather like those of the Light Green, particularly near the quill end, and Violet Light Greens lack the dark blue colour present in the flight feathers of Dark Greens.

SF Violet Dark Greens have a body colour mid-way between a Dark Green and an Olive.

SF Violet Olives are very similar to Olives.

DF Violet Light Greens, Dark Greens and Olives are expected to be slightly darker than the corresponding SF birds, but these colours have not been reported reliably.

Blue Series

SF Violet Skyblues have a body colour ranging from dark skyblue to medium cobalt. Most look rather like pale Cobalts. The colour of the tail and flight feathers are the most reliable distinguishing features. Cobalts have navy blue tails throughout their length, while Violet Skyblues have tails which shade to turquoise at the quill end. The flight feathers of Cobalts are dark blue, those of Violet Skyblues have a glossy turquoise iridescence rather like those of Skyblues but slightly darker.

Visual Violet cock

SF Violet Cobalts have a bright violet body colour, and are known as Visual Violets.

SF Violet Mauves are quite similar in appearance to normal Mauves. Sometimes a violet tinge is visible in Violet Mauves when placed next to a Mauve, particularly in the rump area.

DF Violet Skyblues are similar in shade to SF Violet Cobalts but are a deeper richer violet colour. These, too, are Visual Violets. Their tails are dark blue with a residual pale blue or turqoise at the quill end, whereas SF Violet Cobalts have uniform dark bluey-violet tails.

DF Violet Cobalts are similar to SF Violet Cobalts but usually have a deeper richer violet colour. These are also Visual Violets.

DF Violet Mauves are believed to be similar in colour to SF Violet Mauves.

Historical Notes

In Australia, Mr A Burton of Sydney was breeding Violets by 1934 and Mr Harold Pier exhibited a Violet in the same year.

In Europe, the first mention of a bird which might have been a Visual Violet was by C af Enehjelm in 1935 in Copenhagen. In a letter to the Budgerigar Bulletin, he said he had bred a Cobalt, "which I would call violet". In a later article he gave full details of his Violet birds, remarking that earlier birds he had seen which were bred in Germany in the late 1920s and marketed as Violets were little different from normal Cobalts and lost their violet colour with age. His first true Violet, mentioned above, was bred from an apparent Dark Green/blue cock obtained from a friend and a Cobalt hen. This Dark Green/blue cock was "very heavily suffused with blue (cobalt)". Presumably it was in fact a SF Violet Light Green/blue. He went on to breed several more Violets from the progeny of this bird.

Skyblue cock

In 1924 in England and 1932 in Australia birds called "Royal Blues" were bred, but these were not Violets. In the UK the opinion of the highly respected budgerigar breeder, C H Rogers, writing in 1937, was that a true Violet was first seen in England at the Cambridge Diploma Show that year. The Violet hen was exhibited by Stevenson and Tucker. As they had eight other birds of the same colour they must have first bred Violets some years earlier.

As Violet Light Greens are very similar in appearance to Dark Greens it seems likely that a small number of Violet Light Greens were being bred in several places in the 1920s, masquerading as Dark Greens. Their true nature remained hidden, only being revealed when they were mated to birds of the blue series. This could not happen until blue budgerigars became readily available, which was not until the 1930s.

Genetics

The Violet mutation has an incompletely dominant relationship to its wild-type allele. That is, there are three distinct phenotypes, possessing zero (the wild type), one (the single factor heterozygote) and two (the double factor homozygote) Violet alleles, with the heterozygote having an intermediate appearance between the wild-type and the homozygote.

Because the Violet factor is always visibly expressed no budgerigar can be split for Violet. The heterozygotes of Violet — the SF Violet Greens and Blues — correspond to the splits of the recessive mutations.

Cobalt cock

The Violet mutation is autosomal, but it has not yet been determined whether there is a linkage to any of the other budgerigar mutations. There has been a long-held view that the Violet mutation was linked to the Blue and Dark mutations, but doubt has been cast on this. It seems more likely that the unexpected breeding results which prompted the view were caused by incorrectly identifying birds carrying single and double Violet factors. There is no reported measurement of this or any other linkage.

In the past there was a view that the Violet allele was lethal in double factor form, but this is now disproved with many breeders reporting DF Violets.

The Dominant Grey budgerigar mutation, often called the Australian Grey or simply Grey, is one of approximately 30 mutations affecting the colour of budgerigars. 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.

When combined with the Dark mutation 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) 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 Codes, as shown to the right.

Light Green cock

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, 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 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.

Grey-Green cock

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.

The Yellowface I budgerigar mutation is one of approximately 30 mutations affecting the colour of budgerigars.

Appearance

The Yellowface I Skyblue variety is the same in appearance as a normal Skyblue except that the forehead and mask, which is white in the normal Skyblue, is replaced by bright yellow, the short tail feathers show yellow instead of the normal white, and the undulations on the wings are often faint yellow. The yellow on the mask tends to leak down onto the breast to a small degree, giving it a green tinge. In juvenile plumage the yellow is considerably fainter and does not appear on the forehead, which is barred in the usual way, nor does it leak onto the breast to as great an extent.

The Yellowface I Cobalt and Yellowface I Mauve varieties have similar yellow markings.

The appearance of birds with other combinations of the Yellowface I mutation is discussed under Genetics below.

Historical Notes

In the UK, a yellowfaced bird was first produced in 1934-1935 by E H Stevenson of Cambridge - a yellowfaced Cobalt cock, and Mrs G Lait of Grimsby and J Long of Gorleston-on-Sea both bred them in 1935. A contemporary report of these latter breedings says, "Mrs Lait mated a dark green cock to a greywing mauve hen, and in their third nest was a pale greywing mauve hen with a distinct (light lemon yellow) mask and bib, with the under tail feathers yellow and with yellow on the wings in the places where the normal blue bird is white. This hen ... was mated with a cobalt/white cock and they have produced five youngsters, all having yellow masks like their mother. Mr Long's birds were bred from a dark green of a somewhat olive shade mated to a rather unusually coloured hen, which appears to be a green but has a turquoise suffusion on the breast, etc. The first nest produced 3 cobalt birds with yellow masks, etc, like Mrs Lait's birds described above, and one green-blue bird like the mother. The second nest produced exactly the same result."

By 1937 several breeders in the UK had yellowfaced birds, and Stevenson and Tucker exhibited one at the Crystal Palace in that year. Yellowfaced birds were also being bred in Europe, as it was reported that W H Higham imported one in 1937, and in Australia. In all, there were at least seven reports of yellowfaced birds appearing between 1934 and 1937, seemingly independently. Some of these were very similar, others were slightly different. It is impossible to tell now which of the yellowface mutations were involved, but as some of the reports mentioned normal-looking birds which bred 100% yellowfaced young it seems likely that these at least were the Yellowface I mutation.

Genetics

The genetics of the several Yellowface mutations and their relation to the Blue mutation are not yet fully and definitively understood.

Much confusion and misunderstanding have arisen because the popular names given to these mutations are misleading. These mutations do not generate a yellow face, as the names might suggest. Rather the action of all these mutations is to reduce the yellow pigmentation, either entirely or to some degree, with respect to the wild-type Light Green. Had these mutations been named 'Yellow-less' rather than 'Blue' or 'Yellowface' their action might have been more easily understood from the outset. But the traditional names are engrained and are retained here.

The prevailing view is that the Yellowface I mutation, together with the Yellowface II and Blue mutations, are members of an allelic series situated at the Blue locus. Although some breeders still dissent from this view it is the one followed here.

On its own, the Yellowface I is a simple autosomal recessive with respect to the wild-type. Visibly, its action appears to be identical to that of the Blue mutation. The heterozygote or Light Green/yellowface I with one Yellowface I allele and one wild-type allele is visibly indistinguishable from a Light Green, and the homozygote with two Yellowface I alleles is visibly indistinguishable from a Skyblue. Due to this similarity in the action of the Blue and Yellowface I mutations, Bergman and Onsman have adopted the convention that these mutations be named Blue I and Blue II.

The Yellowface I Skyblue variety, described in Appearance above, is a composite of the Blue and Yellowface I mutations, having one allele of each. When two Yellowface I Skyblues are paired together, half the progency will be Yellowface I Skyblues and half will be normal Skyblues in appearance. But half of these apparent Skyblues will, in fact, be double factor Yellowface I's.

The loci of the Dark budgerigar mutation and the Blue allelic series are situated on the same autosome, so the Dark mutation is linked to the Blue allelic series (see genetic linkage). The cross-over value (COV) or recombination frequency between the Dark and Blue loci is commonly stated to be about 14%, but some experiments have found much smaller values (see Genetics in the Dark budgerigar mutation).

The Blue 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: Skyblue, Cobalt, Mauve and Violet.

Appearance

The Blue mutation changes the colour of the body feathers, which are light green in the wild-type, to skyblue and the colour of mask and other parts which are yellow in the wild-type, to white. In the domesticated bird this mutation changes the Light Green variety into the Skyblue variety, the Dark Green into the Cobalt and the Olive into the Mauve.

The green colouration of the wild budgerigar is due to the combined effect of a yellow pigment and an interference effect similar to that which gives colour to petrol on water, which in the budgerigar produces a blue colouration. Yellow pigment is present in the outer layer (cortex) of the cells forming the barbs of all feathers of the wild budgerigar with the exception of the cheek patches, although it is very weak in the outermost flight feathers. The distribution of the yellow pigment is clearly shown in the Lutino. The Blue mutation totally inhibits the production of this yellow pigment, and as far as is known, it has no other effect.

The yellow pigment in young budgerigars is paler than in adults, which makes green budgerigars in nest feather appear duller and Lutinos appear paler. A brighter and stronger yellow colouration appears after the first moult.

The chemical nature of the yellow pigment in budgerigars and other psittacidae is unknown, and in the absence of a chemical name George A Smith coined the term "psittacins" to cover the yellow, orange and red pigments found in parrots and parrot-like birds. Psittacins impart a far more constant intensity of colour to feathers than do the more commonly found carotenoid pigments such as xanthophyll, the yellow pigment found in the canary. At each moult the canary extracts xanthophyll directly from its food, and the depth of colouration of the growing feathers is determined by the concentration of xanthophyll in its diet. Budgerigars cannot be colour-fed in this way, because they do not use xanthophyll as a pigment.

The Blue mutation provides a widely accepted division of domesticated budgerigars into two colour classes: the "Green series" and the "Blue series". Birds of the Green series exhibit yellow pigmentation, while birds of the Blue series lack yellow pigmentation. These names can be misleading, since some birds belonging to the Blue series, such as Albinos, are not blue; similarly, Lutinos belong to the Green series, yet are not green.

In combination with the Dark budgerigar mutation the body feathers become deeper shades of blue. A blue budgerigar with a single Dark factor is called a Cobalt, and one with two Dark factors a Mauve. The World Budgerigar Organisation has established precise standards for budgerigar body colours using the Pantone Codes, as shown to the right.

Skyblue cock

Historical Notes

The Blue mutation made its first recorded appearance in 1878 in the aviaries of M Limbosch of Uccle, a suburb of Brussels, but this strain died out, it is believed, in 1881. Blues appeared independently in Holland between 1881 and 1885, and a Mr Pauwels of Everberg, near Brussels, reintroduced them to Belgium from this Dutch strain.

The first Blues to be seen in England were some exhibited by Messrs Millsum and Pauwels at the Horticultural Hall in 1910 and the Crystal Palace in 1911. Mr D Astley owned Blues in 1911, and it is recorded that C Pelham Sutton of Putney bred a Blue in 1912.

Blues remained quite rare until the 1930s, fetching up to £100 per pair in Japan around 1928, about the cost of a car at the time.

Genetics

The Blue mutation is recessive to its wild-type allele, so a bird possessing a single Blue allele (the heterozygote) is identical in appearance to the wild-type light green. That is, the presence of a single wild-type allele is sufficient to permit the full production of the yellow psittacin pigment. Among the budgerigar fancy such a bird is said to be a Light Green split blue, usually written Light Green/blue. In a bird which has two Blue alleles (the homozygote), the lack of the wild-type allele means the yellow pigment can no longer be produced, and so the body colour is blue — the Skyblue.

The locus of the Blue gene is situated on one of the autosomal chromosomes. The Yellowface Blue I mutation, the Yellowface II mutation form an autosomal co-dominant series of alleles with the Blue mutation.

Light Green Cock

The loci of the Dark budgerigar mutation and the Blue allelic series are situated on the same autosome, so the Dark mutation is linked to the Blue allelic series (see genetic linkage). The cross-over value (COV) or recombination frequency between the Dark and Blue loci is commonly stated to be about 14%, but some experiments have found much smaller values (see Genetics in the 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 carring the Dark factor are identical to the wild-type Light Greens or Skyblues in every respect except body colour and tail feathers. The body is darker in Dark Greens and Cobalts and darker still in Olives and Mauves, and the long tail feathers are darker in proportion. All these varieties have normal violet cheek patches.

The Dark Green's body colour is a rich shade of laurel green, and Cobalt's a deep blue, approximating to royal blue. The Olive is similar in shade to a Grey-green, but it may be easily distinguished by its cheek patch, which is violet in the Olive and grey in the Grey-green. The Mauve is rather a dull colour, quite different from the brilliant Violet and Cobalt. In nest feather the Mauve is a shade of lavender, almost grey, but the violet cheek patch, although somewhat darker than in other varieties, identifies it as a Mauve.

The Violet Cobalt (a composite of the Blue, Dark and Violet mutations) is a brilliant shade of violet, rather similar but not quite as deep as and rather bluer than the wild-type violet cheek patches.

The World Budgerigar Organisation has established precise standards for certain budgerigar body colours using the Pantone Codes, as shown to the right.

Historical notes

The Dark mutation ^[1] is common in the wild as Dark Green budgerigars have been observed in wild flocks on several occasions^[2]. One of the earliest to be seen was one captured during an expedition to Australia and exhibited in a London museum in 1847 ^[3]. But the Dark mutation was not seen in the domesticated budgerigar until the summer of 1915 when a Dark Green was observed by Monsieur A Blanchard in his aviaries in Toulouse ^{[3] [4]}. At the time, Toulouse was the main commercial centre for budgerigar distribution in Europe, handling thousands of imported and aviary-bred birds each year. The origins of this first Dark Green are not known. Dark Greens were known initially as Laurel Greens, a name which remained popular throughout the 1920s.

Light Green cock

Dark Green cock

Olive cock

Mon. Blanchard produced the first Olives from a pair of Dark Greens in the autumn of 1916^[5], and J D Hamlyn imported some of the early Olives to England from France in 1918^[6].

The first Cobalts were bred by Mon. Blanchard in 1920^[5], and by George F Hedges in 1923^[6] while he was the aviary attendant for Madame Lecallier in France. These were initially called Powder Blues^[5]. Some of these latter Cobalts were purchased by Mrs Dalton Burgess and imported to England^[6]. She exhibited one (as a Royal Blue) in February 1924 at the Crystal Palace and later that year bred the first Mauves from them^[3]. She called the Mauves French Greys in nest feather, and when adult they were known as Lilacs or Lavenders.

The blue forms of the Dark mutation were far more popular than the Greens and commanded fantastic prices in the mid-twenties. In February 1927 Mauves and Cobalts were sold for £175 a pair, but by 1931 the price was down to £2 a pair, as more and more were quickly bred.

Genetics

The Dark mutation has an incompletely dominant relationship with its wild-type allele. That is, it shows a visible effect when present as a single factor (heterozygote) and a different effect when present as a double factor (homozygote). In the green series varieties the Dark Green has one Dark allele and one wild-type allele at the Dark locus and the Olive has two Dark alleles. In the blue series varieties the Cobalt has one Dark allele and one wild-type allele and the Mauve has two Dark alleles.

Olive cock

Skyblue cock

Because the Dark factor is always visibly expressed no budgerigar can be split for Dark. The heterozygotes of Dark — the Dark Greens and Cobalts — correspond to the splits of the recessive mutations.

The loci of the Dark mutation and the Blue allelic series are situated on the same autosome, so the Dark mutation is linked to the Blue allelic series (see genetic linkage). The cross-over value (COV) or recombination frequency between the Dark and Blue loci is often stated to be about 14%^[7], but several careful measurements of this COV show quite widely varying results. Early measurements by Duncker and independently by Steiner obtained values of 14% and 7.6% respectively, and T G Taylor and C Warner collected results which showed only 5 cross-overs in 140 - a COV of 3.6% ^[8]. Included in these were results from T G Taylor's own experiments, in which he found no cross-overs in 86 birds bred^[8]. It is now known that the environment and other genes can influence the COV, so some variability should be expected. A reasonable average of these measurements is a COV of 8%.

Dark Green/blues have one Dark allele and one Blue allele together with one each of the corresponding wild-type alleles. The linkage between the Blue and Dark genes gives rise to two types of Dark Green/blue birds, both visually identical.

• Type I Dark Green/blues are bred by mating Mauves to Light Greens and have the two mutant alleles on the same chromatid. Geneticists call this 'coupling' rather than 'Type I'. Because of the linkage, the Dark and Blue alleles from Type I birds tend to be inherited together in their progeny. When mated to Skyblues, Type I birds produce predominantly Light Green/blue and Cobalt progeny, with Dark Green/blue Type II and Skyblues resulting rarely from a cross-over.

Cobalt cock

Violet cock

• Type II Dark Green/blues are bred by mating Skyblues to Olives and have the Dark and Blue mutant alleles on opposite chromatids. Geneticists call this 'repulsion' rather than 'Type II'. Because of the separation, the Dark and Blue alleles from Type II birds tend to be inherited separately in their progeny. When mated to Skyblues, Type II birds produce predominantly Dark Green/blue Type II and Skyblue progeny, with Light Green/blue and Cobalts resulting rarely from cross-overs.