Taeniopygia guttata internationalis

The Light Cheeked Zebra Finch (Bleekwang)

by Berend Bosch, Nijmegen, the Netherlands, 26-Jun-98

Original article dated 10-JUN-97 translated from Cees Pijnappels' Zebra Finch Pages

1. Introduction and justification for this article.

Part of the NZC's Technical Day 1997 was a brief stocktaking of the situation of the Light Cheeked mutation (Bleekwang). The goal of this stocktaking is to determine if a first step towards recognition could be taken, leading towards admission into the standards. Ultimately it was decided to accompany the development of the Light Cheeked mutation with a preliminary charter - a breeding guide.

The following document provides this charter and breeding guide in writing.

2. What influence does the Light Cheeked mutation have on the wild colour.

2.1 Effects on the phaeomelanin markings.

These are the cheek patches and the flanks. Apparently, the Light Cheeked mutation has most effect on the underside. On the wild colour (i.e. normal Grey), both the barbules and hooklets on these feathers have high quantities of phaeomelanin. We see this colour as a deep orange on the cheeks and chestnut on the flanks. As a consequence of the Light Cheeked mutation, the quantity of phaeomelanin grains is decreased. With a weak Light Cheeked factor, this reduction is restricted to the tips of the barbules, while the hooklets remain filled with phaeomelanin grains. When the Light Cheeked factor is stronger, the phaeomelanin in the base of the barbules is also reduced and then amount of grains in the base of the hooklets is reduced. The Light Cheeked factor has a large variation. On birds with an ideal Light Cheeked factor the phaeomelanin in the cheek patches should be reduced almost completely. In stead, eumelanin appears on the tips of the hooklets in this area, which we believe corresponds to the grey body colour.

2.2 Effects on the eumelanin markings.

By eumelanin markings, we mean the beak lines, tear markings, zebra stripes, breast bar, rump side markings, and the dark blocks on the upper tail feathers. To our knowledge, the Light Cheeked mutation has not had any effect on these markings so far. It is believed that if careful selection of prominent breast bars is neglected, the size of the breast bar will become smaller. However, this is true also for Zebra Finches that do not have the Light Cheeked mutation, so this is not necessarily a mutation specific characteristic.

2.3 Effects on phaeomelanin in the colour areas.

On the belly and rump feathering, the Light Cheeked mutation causes a larger quantity of phaeomelanin. So far, it is not believed that the mutation has any effect on the back/wings.

2.4 Effects on eumelanin in the colour areas.

In a number of cases, a very slight reduction of eumelanin has been noticed. In these cases, the reduction is perceived as minimally lighter back/wing colour.

2.5 Dimorphic characteristics of the Light Cheeked mutation.

The Light Cheeked mutation primarily affects the male characteristics of the Zebra Finch. An adult Light Cheeked Grey female is not recognisable as such. At times, it appears that Light Cheeked nestlings have no phaeomelanin in their downs, while nestlings that aren't Light Cheeked do have phaeomelanins in their downs. This characteristic has not been examined satisfactorily to be able to say that this is a mutation specific characteristic.

3. Inheritance of the Light Cheeked mutation.

The Light Cheeked mutation is autosomal dominant.

The formula for a Light Cheeked Grey male is: xb+ // xb+ , B/B+

The formula for a Light Cheeked Grey female is: xb+ // y , B/B+

b+ for the wild allele of the eumelanin oxidation factor.

B for the Light Cheeked factor.

The occurrence of a lethal factor with double-factor Light Cheeked is currently indicated.

4. The decision making process towards recognition of the Light Cheeked mutation.

Since the mentioned Technical Day, the NZC has decided the existence of the Light Cheeked mutation is indisputable. However, admission into the standards is not on the agenda yet.

It has been decided to give judges and breeders a guide for the further development of the Light Cheeked mutation through a draft standard. It has been decided that both cheeks and flanks should be clearly recognisable in both colour and contour. It has also been decided to that a creamy belly is acceptable.

5. A first start towards a standard description.

The standard only describes the male. The Light Cheeked female cannot be recognised as such and is therefore not included in the draft standard.

The Standard.

The variety: Light Cheeked Grey.

Male, markings:
Tear marks, beak line , breast bar and zebra stripes , flanks in the height of the rump, and the dark blocks of the upper tail feathers:	Black.
Between tear marks and beak line:	White.
Cheek patches:	Light orange.
Flanks:	Light orangebrown (chestnut) with round white spots.
Male, colour:
Head and neck:	Grey, head with ticking.
Back and wings:	Grey, slightly different from the head. Wings even in colour. The wing shafts are allowed to have a lighter edge. The grey back/wing colour may be somewhat lighter than the normal Grey variety.
Rump and belly:	Offwhite
Tail feathers:	Dark grey.
Male, eyes and horn parts:
Beak:	Red , the female somewhat lighter than the male.
Legs/feet and nails:	Orange.
Eyes:	Dark - a lighter colour is permitted.

The following points give a positive impression when judging:

On the male:

***A satisfactorily dark coloured grey head.

***Satisfactorily dark coloured even grey back and wings.

***Nice light orange cheek colour and light chestnut flank colour.

***Sharp edges on the cheeks and flanks.

***Well proportioned (and straight) black markings on the underside.

Even though this is not a specific trait of the Light Cheeked Grey variety, this contributes greatly towards the attractiveness of the variety.

The following points give a negative impression when judging.

On the male:

***A light back/wing colour which gives a bleached or faded impression.

***A fawnish shine on the back and wings

***A blotchy colour on the back and wings.

***A too light cheek and flank colour.

***A grey colour in the cheeks

***An less than sharp edge on the cheeks.

***White spots in the flanks that are not round. Flanks that are vague in colour. ')

***White edges and white tips on flights.

***Uneven ') and poorly proportioned ') or unsatisfactorily coloured black markings.

***The white area between tear marks and beak lines extends above the eye.')

***Zebra stripes that do not extend fully up to the lower beak. ')

***Zebra stripes that extend to under the cheeks - sometimes even up to above the eye. ')

') Even though these characteristics are not specific to the Light Cheeked Grey variety, these faults influence the quality of the variety.

6. Combination possibilities with the Light Cheeked mutation

At first, the number of breeders that showed an interest in the Light Cheeked mutation was limited. The mutation is not as appealing as for instance the orange breasted or the black cheeked mutations - the changes are simply too vague for that. It is therefore good that the small circle of interested breeders try to develop the normal version of this variety as optimally as possible.

In the future, we will see a limited number of combinations involving the Light Cheeked factor which can be considered an asset to the Zebra Finch hobby. The following table lists these (im)possibilities.

Light Cheeked combined with:	Possibilities and advice
Grey:	Considered the most prefered variety for now. Try to let the mutation show its full potential in this variety.
Fawn:	Since the Light Cheeked mutation has a tendency to have extra phaeomelanin in the belly feathers, the experimental breeder has a chance to show this quality in optimal conditions.
Light Back:	Not desired - detrimental to the qualities of the Light Back.
Chestnut Flanked White:	Not desired - detrimental to the qualities of the CFW mutation.
Agate:	For now, this is an experimental possibility. Let both mutations develop fully first.
Silver (Pastel):	Not desired as such. Because of the phenotype, a Silver with too dark cheeks and flanks may be improved. It is better to use normal selection practices to do this.
Yellow Beak:	Is currently possible, but will probably not be all that appealing.
Crested:	Is currently possible, but will probably not be all that appealing.
Black Breasted:	Probably the only combination which would be interesting. The expanded lightly coloured cheeks could be attractive.
Penguin:	Not desired - detrimental to the qualities of the Penguin mutation.
Isabel:	Not desired - detrimental to the qualities of the Isabel mutation.
Cheeked:	A possibility for the experimental breeder. Because of the phenotype, it could probably be used to put a good cheek colour on the Grey Cheeked. However, the flanks would mostly be too light. This combination would be difficult to recognise as a combination.
White:	Unnecessary.
Pied:	Not desired in Pied, since the Light Cheeked mutation is a melanin reducing factor.
Black Cheeked:	A test mating is recommended. It is not obvious what the effects the Light Cheeked factor has on the Black Cheeked factor.
Orange Breasted:	Is currently possible to breed experimentally. It is recommended to let both the Orange Breasted and Light Cheeked mutations develop further first.
Black Faced:	Is currently possible, and is easily recognisable as a combination.
Eumo:	A possibility for the experimental breeder. Because of the phenotype, this combination could probably be used to put a good cheek colour on the Eumo. However, the flanks will mostly be too light. This combination would be difficult to recognise as a combination.
Light Back Silver:	Because of the phenotype, this combination could probably be used breed good Light Back Silvers. Breeding test will have to show if the cheeks get a grey haze.

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