by Pantcho Tomas
Whenever Clearwing breeders in Australia and the United Kingdom correspond a lively exchange on the topic of who has "real" Clearwings is never far away. The most frequent criticisms are that British Clearwings are Full Body-coloured Greywings (compound Greywing Clearwings), while Australian Clearwings are all Cinnamon, hence the clear wings. If one was to believe all of this banter, then the idea that two separate mutations exist would soon present itself. Fortunately, another explanation may provide a more suitable resolution, and that is the action of modifier genes.
Early Selective Development
Even though Clearwings were first developed in Australia, it is folly to presume that early examples were similar to those that exist today. It took many years of selective development before they were standardised and even accepted as a separate variety to heavily Suffused Yellows and Whites. Indeed, progressive changes in early Standards of Perfection reflect this. According to the late Cyril Rogers, even the first pairs that were imported to England in 1936 produced offspring that varied widely in their visual characteristics.
While early photographic evidence is lacking, the first coloured prints of Australian Clearwings were provided by Neville Cayley in his two editions of "Budgerigars in Bush and Aviary" in 1933 and 1935. Despite the temptation to ascribe an opinion of artistic license in these prints, early evidence suggests that the first Clearwings were probably not unlike many of those in the UK. today. The concentrated efforts of a handful of breeders were responsible for ultimately removing all vestiges of markings from the wings and intensifying the body colour. Among these was Harley Yardley of Sydney, who achieved a succession of Grand Champion awards with his Clearwings in the 1950's and 60's. Later on, Arthur Brown, also of Sydney, gained some fame for the exceptional wing clarity of his Clearwings.
Unknown Role of Black-eyed Yellows and Whites
These gentlemen, along with others, were able to fix wing clarity to such a level of perfection that I doubt breeders outside of Australia can believe it a possibility. There are no precise records of how it was done except that with each successive generation, Clearwings with clearer wings were paired together. However, interspersed with this, are suggestions of the critical role played by Black-eyed Yellows and Whites (the British exhibition Light Yellows and Whites). Unfortunately, it is hard to visualise how a variety in which today's examples have clearly visible wing markings can be used to eliminate the wing markings from another variety. Earlier specimens were possibly free of this feature, so their role should not be ignored.
Nevertheless, some of today's breeders have maintained exceptional wing clarity in their Clearwing studs, despite significant pressure by those who feel other non-varietal characteristics of Clearwings are more important. Those who fall into this category must take heed that, even with pairings where both Clearwings have exceptional wing clarity, offspring with poor wing clarity emerge. The opposite does not seem to occur. In any pairing, at least one partner must possess exceptional wing clarity for the feature to be passed on to the next generation. Hence it is a real possibility that if this feature is ignored, then, as a characteristic, it will be lost. This would then be superseded by Clearwings with wing markings, which breeders in Australia would consider characteristic of the Greywing variety.
The Role Played by Modifier Genes
Few would
deny that in any nest of Clearwings, variability exists when it comes to Clearwing
characteristics. Some are exceptionally small, some have deeper
body colour, and some have clearer wings, while others look like Greywings.
Indeed,
it is often said that the smallest will have the clearest wings, while the largest
have the "dirtiest" (most heavily marked) wings. This is not
always the case, and many small birds with "dirty" wings are ignored
in this oversimplification. Large birds with good clear wings can be bred, and
indeed are bred, but there are few of them.
Individual birds can attribute this divergence in characteristics within a single variety to various "modifier" genes carried. These would have to be polygenic in nature as they seem to be somehow linked to the Clearwing gene and possibly also to the Dilute and Greywing genes. Over many years of selective breeding, some of these modifier genes seem to take on a dominant role, despite being recessive. This often becomes apparent when Clearwings from different lines are paired together. Moreover, inbreeding to implant one characteristic nearly always brings with it other, sometimes less desirable characteristics. In the budgerigar fancy, Standards of Perfection change with time, hence forty years of selective breeding may sometimes need to be reversed in one or two generations. As every Clearwing fancier will testify, this is an unreasonable request. Unfortunately, those who don't breed Clearwings often make such a request.
To an outsider, it might be said that all Clearwings look the same. A written Ideal or Standard of Perfection could also give the same impression. It is only when you breed Clearwings that your perception changes. To me, observing the subtleties of this variety is "compulsive viewing". To others it is frustrating, unrewarding, pointless and considered as the first sign of insanity. I hope that the following observations will be of benefit in illustrating the influence of some of the many unique modifier genes that the Clearwing variety can carry.
Tail Colour
Ignoring what is written in Standards, most Australian Clearwings have a tail colour that can vary from an off-white colour to pale grey. This invariably shows some suffusion of body colour. With Yellow-wings, the suffusion may be yellow, or varying shades of green. In the majority of cases there is a relationship between the colour of the flight feathers and the colour of the tail. A blue tail on a Yellow-wing is extremely rare, but when it does occur it is nearly always associated with a Violet-factor, for example, Violet Dark Green. Moreover it seems to be well known that the violet-factor can influence tail colour in Clearwings.
Much is made of the fact that the central tail quill of Australian Clearwings is "neutral" in colour. Unfortunately, too much is made of this expression, it being originally adopted to sort out Greywings with full body colour and their mid-grey central tail quills from Clearwings. Other identification features are far more prominent, particularly the colour of the flight feathers.
Colour of the Flight feathers
A wide variation in the colour of the flight feathers among Clearwings is possible, even in a single nest. In the very best examples they are white, while in the worst they are mid-grey. In Yellow-wings the white is associated with varying amounts of yellow suffusion. Birds with mid-grey flight feathers are generally culled because they often have very prominent wing markings. Moreover, in the past they were shown as Greywings with full body colour or alternatively sold on to Greywing breeders. There is clearly a relationship between the colour of the flight feathers and the tail colour; darker flight feathers signify a darker tail.
Perpetuating Clearwings with dark grey flight feathers invariably leads to a loss of wing clarity; hence they are often the first to be culled. However, when paired to Clearwings with white flight feathers a percentage of the progeny will also have white flight feathers. Moreover, despite the efforts of many breeders in only pairing together Clearwings with white flight feathers, grey-flighted Clearwings continue to emerge after many generations. This feature seems to be controlled by an additional modifier gene that is easily lost from a Clearwing stud unless it is actively cultivated. Therefore, deciding on how much grey one accepts in the flight feathers is usually a personal choice, often controlled by the heaviness of the wing markings.
Shade of Grey in the Wing Markings
Any Clearwing
breeder working with compound Greywing Clearwings (Full Body-coloured Greywings)
in the
mistaken belief that they are pure Clearwings may find it hard
to accept that some Australian Clearwings are devoid of wing markings. Moreover,
the grey wing markings present on Suffused Dilutes, are totally unacceptable
on Australian exhibition Yellow-wings and Whitewings as they are considered
far too dark.
Alternatively,
to say that all Australian Clearwings possess exceptional wing clarity, is certainly
unrealistic boasting. The feature is restricted to a handful of
studs, most with an ancestry dating back to the birds of the late Arthur Brown
of Sydney. Many exhibition Clearwings have pale grey markings on
the wings and very prominently on the back of the
head. Cinnamon
Clearwings also have reduced wing markings, but in addition to reduced body
colour, the markings on the back of the head are brown.
I have often
read that in Britain, single-factor Clearwings (those split for Dilute) have
clearer wings than double-factor Clearwings. This definitely does
not apply to Clearwings in Australia. I would like to be able to
say conclusively that the reverse is true, but know from personal experience
that exceptional wing clarity is not the domain of either single-factor or double-factor
Clearwings. Moreover, when Clearwings of either genotype are paired
to Suffused Dilutes bred from Normals, exceptional wing clarity is immediately
lost in all of the Clearwing progeny. There seems to be a wide
dispersion
in the depth of the markings among the offspring from this type of pairing,
some being acceptable for exhibition purposes, but most being relegated for
use as stock birds or culled. When these newly created single-factor
Clearwings are paired back to others with exceptional wing clarity, some of
their offspring inherit exceptional wing
clarity. However, many
dirty-winged Clearwings are perpetuated.
Suffused Dilutes bred from Australian Clearwings are different in appearance to Suffused Dilutes bred from Normals, and seem to be modified through interaction with the Clearwing.
By comparison, the body colour is more washed out, the flight-feathers are paler, tending towards white, and the colour of the wing markings are much paler. I call these "Clearwing-modified" Dilutes as they are instantly recognisable when compared with Suffused Dilutes bred from Normals. They are quite suitable as mates for Clearwings but are not often used.
Intensity and Clarity of the Wing Markings
The markings
on the wing coverts and scapulars of Clearwings fall into two basic categories.
That is, those that are thin and well defined, or those that seem
to be blurred and smudged. Some have suggested that this difference
is due to the feather type being either yellow or buff, but a similar difference
in Normals is not easily recognisable. Clearwings with the clearest
wings frequently have very pale, thin, well-defined wing markings. In
the context used here, smudged does not necessarily infer "dirty"
wing markings, as well defined markings can appear quite dark and also
be referred to as "dirty"
or "muddy".
Pairing together two Clearwings with well-defined wing markings can occasionally produce a small percentage of Clearwings with blurred markings. What happens when two of these are paired together is beyond my experience but I suspect more are bred..
The same
differences in the intensity and clarity of the wing markings of Clearwings
exists in Suffused Dilutes.
Furthermore, I have often read that this is used
as a characteristic separating Suffused Dilutes from Greywings.
Greywings
should have sharp, well-defined markings while Suffused Dilutes possess
smudged markings. Clearly, such a definition has no justification,
as Australian Clearwings with good clear wings can have either type of wing
marking.
Moreover, I suspect that Clearwings with smudged wing markings,
near to mid-grey in colour, were regularly shown in Sydney as Greywings with
full body colour. Hence the often repeated belief that Clearwings
can be split for Greywing.
Much better to state that Clearwings with "dirty",
smudged markings can come from Clearwings with no visible markings.
Cheek Patch Colour
Published Standards, throughout the world require Clearwings to have a cheek patch which is violet in colour. If this ruling was to be adhered to, then almost every Clearwing exhibited in Australia would have to be wrong-classed. There is a very close relationship between the colour of the flight-feathers, colour of the tail, absence of wing markings and cheek patch colour. When the tail and flight-feathers are almost white, wing markings are often absent, and the cheek patch colour is a very pale violet-mauve colour. This is similar in colour to that found on heavily suffused Dilutes. As the flight-feathers and tail colour get darker, so do the wing markings and, accordingly, the cheek patch colour. Throat spots also become more pronounced.
Clearwings
with the heaviest wing markings have a cheek patch closest to the violet cheek
patch found on Normals.
Judges are aware of this and so are very lenient
when examining cheek patch colour on Clearwings. Most breeders also
realise that breeding Clearwings for a rich violet cheek patch means giving
up on clear, pristine wings. Thus in Australian Clearwings, a reduction
of melanin in the wing markings, flight-feathers and tail leads to a reduction
of the melanin in the cheek patch.
Evenness, Depth and Intensity of the Body Colour
Maintaining
a rich, vivid and even body colour has always been a primary concern for Clearwing
breeders. This is because, occasionally, Clearwings are bred which
possess about 50% of the body colour of Normals, and these are not Cinnamon.
Even more frustrating is the production of Clearwings with virtually
no body colour (Dilutes free of wing markings). Both types of "Clearwing"
are always culled and never used for breeding so as to eliminate the fault.
Unfortunately
the fault keeps recurring despite these drastic efforts.
Pairing Clearwings to heavily Suffused Dilutes and Black-eyed Selfs (Yellows and Whites of Light Suffusion) sometimes leads to a reduction in the intensity of the body colour to about 80-90% full intensity. This weakness is not generally considered catastrophic as it can usually be remedied in subsequent generations by appropriate pairings, and by not doubling up on faults.
Evenness
in the body colour is a real problem in some studs of Clearwings, while in others,
it is not a consideration.
Where it is a problem, it can be seen where birds
show a gradual change in colouring from the upper breast (under the mask) to
the feathers around the legs and on the rump. The body colour on
the breast is uneven and patchy with
excess ground colour (yellow or white)
showing through.
It is generally
felt among Clearwing breeders that the incorporation of the violet-factor remedies
the problem, but I
cannot say I agree. I have seen just as many
Violet Dark Green Yellow-wings as Dark Green Clearwings with uneven body colour.
While violet-factor Clearwings (green or blue series) possess a
richer more vivid body colour than those
that are violet-factor free, particularly
when coupled with a dark-factor, patchiness is not alleviated. As
stated previously, not all established studs suffer the problem, it is more
likely another modifier gene at work or deficient.
From personal experience, I have found that pairing together Clearwings from a stud where patchiness in the body colour seems to be an inherent problem to those from a stud where it is not, produces a high proportion of Clearwings with even body colour free of patchiness.
Intensity of the Ground Colour of Yellow-wings
It is only
when Clearwings from different established studs are brought together that strengths
or weaknesses become apparent.
These often reflect the character
of the owner and the goals he or she has set. A feature one breeder
may cultivate another may ignore or even be oblivious to. Indeed,
some of the most successful Clearwings on the show bench have been the result
of chance pairings of newly acquired stock from different sources.
One feature not present in all studs is an apparent "intensifier" gene for the yellow ground colour of Yellow-wings. This acts to enrich the colour of the face, mask, cap, neck and wings, but not the flight feathers and tail. The enrichment is not linked to the dark-factor or to the violet-factor as it can be easily recognised in Light Green Yellow-wings when placed side-by-side. When actually present in Dark Green or Olive Clearwings, with or without an additional violet-factor, its impact is truly startling.
Fortunately the feature is easily perpetuated, and when Yellow-wings with the "intensifier" gene are paired to Yellow-wings free from it, roughly about half seem to inherit richer ground colour. These are easily recognised in the nest as the chicks feather up from the pin-feather stage. This inheritance seems to be random, so that "dirty" Clearwings are just as likely to inherit enriched ground colour as Clearwings with exceptional wing clarity. The only disadvantage of the "intensifier" gene is the appearance of extra yellow in the body colour, which is quite distracting when the body colour is patchy and uneven. I have no idea how the gene could be identified in Whitewings.
Conclusion
Who said breeding Clearwings was easy?
When only variety characteristics are considered, a number of options exist, not just one. With Clearwings in Australia these involve the following: -
The challenge for all Clearwing breeders is to set a working standard to each of these characteristics and then to decide how much variation is acceptable. The task is not as onerous as it seems but does require more forethought than that needed to breed dominant varieties. Coupled to this is the need to improve other non-variety exhibition qualities such as size and type. Very often in any pairing it is a compromise, a case of balancing one feature against another and hoping for the best.
I have not gone into the features required of an exhibition Clearwing to win on the show bench but suggest that it is best to purchase your first birds from a winning stud for swift progress. My intention here was merely to emphasise variety differences that exist among Australian Clearwings.
So, who
has "real" Clearwings, the Australians or the British? The
answer - we all have Clearwings. Perhaps the
question should
be, whose Clearwings have the best "modifier" genes'? Then
there is the question of what do I mean by best? Perhaps the question
is best left unresolved.
© Pantcho Tomas 2002
This article was previously published in Cage & Aviary Birds