The Grizzle Zebra Finch

 

 

 

 

 

The Grizzle Zebra Finch has been around for quite some time, but unfortunabely, they are apparently only common in Australia, rare in Europe and unknown in the UK and US.We would be wise to always inspect our birds, one never knows when a Grizzle might show up. Ken Glasson of Australia was kind enough to supply me with photos and interesting information about the Grizzle in Australia.


The Grizzle Zebra

By Ken Glasson

Western Australia

 

Origins

In 1959 Mr. Bruce Read of Cammeray, Sydney, N.S.W. Australia discovered in Hilton Arthur's dealers establishment in Newcastle an oddly colored grey hen. Through selective breeding he was soon able to reproduce it in both cocks and hens. The body color was the same as normal Greys but all feathers carried white flecking giving a salt and pepper effect. The hen birds carrying grey cheek patches.

After years of breeding he believed that there were 2 types, one with the white fleck and one with the fleck but also carrying a white cap.

Inheritance

The mode of inheritance has been widely believed to be recessive but there have been many occurrences which seem to belie explanation with the usual understanding of recessive. An instance with my own birds:-

I had a stud that probably had limited new stock for about 10 years. None of my birds had ever produced a Grizzle. I imported some stock from Queensland from a breeder who subsequently acknowledged that he had Grizzles in his stock. In the first cross of an imported Grey cock with one of my Grey hens I produced 2 Grizzle Pied cocks.

An Australian vet, Terry Martin, has hypothesized that there may be 2 different genes working in tandem which are responsible for the Grizzle effect.

Breeding issues

This variety is not difficult to breed and reliance on the conventional understanding of Recessive genes will suffice for most purposes. The difficulty with Grizzles is not producing a Grizzled bird but in producing one that matches the Australian Color Standard. Most Grizzles are actually both Grizzle and Pied. Breeding out the Pied factor is the first focus. The second problem is that many Grizzles carry a cap which is not dissimilar to the cap of a Lizard canary but can be more extensive. Whilst I believe this form to be a legitimate Grizzle it is undesirable on the show bench.

The Grizzle effect can be carried to varying degrees and the amount of white present usually increases with successive molts, similar to the way a Penguin develops the frosting. It does however begin with the first molt when the birds get their mature plumage. Some grizzling is limited to white edging on feathers thus creating a scalloped effect on the back rather than the desired salt and pepper look.

Probably the most significant problem after the above is to produce a cock bird with the cheek patch showing only an orange stripe next to the tear stripe. The remainder of the usual cheek patch should be body color (including the required white flecking).

In order to produce the full Grizzle extent and to produce the limited orange stripe it is necessary to pair Grizzle to Grizzle; this causes most Grizzles to be relatively quite small in comparison to most other varieties. Outcrosses to improve size usually reduce grizzling.

There is an associated variant which we call a Reverse Grizzle. It is largely a white bird but with substantial dark flecking on the mantle and wings. Regularly the flights are edged with grey. I have never sought to breed with these birds so can make no worthwhile observations except that I feel mine have all been hens. That may not be true however as I tend to dispose of them reasonable quickly.

Identification

The young are usually easy to identify as the traces of white on the back cause the color to start as a slightly frosted grey. Additionally fledglings show fine white lines on their black beaks, similar to but less than a Pied. The last sign is in the tail. The tail markings of mature birds can vary from a whiter form of normal bars, to what I call a chevron effect and even to a heavily grizzled effect with no bars at all. Almost invariably the young have a chevron style at the start, or at least barring with much wider white than black. We examine our birds quite closely as we are looking for all evidence of pied blood to seek to breed it out. If a youngster shows any Pied it will be there from the start and will not change over time.



GRIZZLES - IS THERE A RIGHT AND WRONG?

By Ken Glasson

 

Over the past few years there has been a lot of discussion at our meetings and shows about Grizzles and Grizzle Pieds. The Standard is as follows:-

GRIZZLE COCK

To conform to the appropriate color, but appearing to show white flecking on all feathers, thus creating a "salt and pepper" effect, i.e. Grizzle. Cheek Lobes to be body color with approximately 12% Cheek Lobe color shown near Tear Drop.

GRIZZLE HEN

Same as the Cock, except all Cock Markings are lacking and replaced by body color. Hens to show Cheek Lobes of lighter body

The cause of the discussion is that this variety actually creates white markings on most or all feathers. Sometimes the white can be the predominant color on an individual feather or area; other times the ideal salt and pepper look can prevail. Also as birds mature some will increase the amount of white.

It is the amount of white which causes the concern. The questions are:-

Is it Pied?

How much white is too much grizzling?

To add to the confusion there are at least 2 forms of Grizzle. One is plainly grizzled on an even basis, all over. The second is commonly called the White Capped Grizzle. This bird has solid white on the head, sometimes running over onto the neck and throat.

If you look at Figure 1 you will see an illustration of a White-capped Grizzle from the front and Figure 2 shows the bird from the back. The point to note from these drawings is that the white cap can be quite extensive, but for some reason it does not affect the cheek lobes. It actually surrounds them. In excessive examples the whole head becomes white except for the cheek lobes. Quite a striking bird.

The debate in NSW seemed polarized between a purist cap permitted stance and a view that caps should be tolerated to give the Grizzle variety a chance to develop.

I favor the latter view. I believe that the capped form is pure Grizzle. It is not a Pied bird which I want to show as a Grizzle for convenience. If it was Pied the capping would break the cheek lobe outline. If that occurs I consider such a bird to be a Grizzle Pied.

White feathers can occur on several parts of a Grizzles body. The most notable are the flights, tail and flanks. Single white flights occur regularly. To ascertain if such a bird should be classed as Pied or Grizzle one needs to look at the feather carefully. There is a difference in the density or intensity of white between a pied feather and a grizzled feather. Strong, solid white is always pied. Grizzled feathers retain some suffusion of body color. Be careful here as flights molted in are likely to be more grizzled than those that have yet to molt. It makes an odd flight look white when it isn't.

The same problem occurs with the tail. If you have bred the bird it is easy as pied markings stay the same from fledging onwards. If a bird has white tail feathers when it comes out of the nest it is pied. Otherwise it is Grizzle.

To check the flanks one needs to look for patches of pied feathers. If there is any pied on the flanks the signs to look for are the white feathers extending into the belly area. If the belly looks to have white patches it is most likely Pied. The difficulty here is with hens as when pied patches occur they are less obvious than on cocks. The broken reddish color stands out on cock birds.

The other problems with Grizzles are the extent of orange in the cheeks and the type of markings on the flanks and tail (see Figure 3). The Grizzle factor seems to affect birds differently so that flanks and tail can sometimes have a chevron effect and at other times be more simply grizzled. Whilst not specified in the Standard, I doubt that anyone would rule either style out. The cheek lobes are more problematic. The Standard certainly calls for 12% orange next to the tear stripe. Lots of Grizzles have almost full cheeks. I believe we should tolerate this as still being Grizzle but penalize it with some deduction of points depending on the extent of the coloring.

The drawings accompanying this article were reproduced from an article first published by the Zebra Finch Society Australia Inc. The Capped Grizzle drawings are modifications of the original.

Over the years there have been many attempts to establish guidelines which would facilitate distinction between Grizzles and Pieds without discouraging Grizzle breeders. This remains a very necessary objective as this attractive variety is still being held back by this lack of clarity and by some inflexibility towards the issues involved.