Sunday, November 29, 2009

Geoff Walker Seminar - Cobalt Canary

On Saturday morning at 10 AM, the National Colorbred Association hosted a seminar in the new color judging area given by Geoff Walker, noted author of Coloured, Type, and Song Canaries who judged the New Color Division. Geoff is not only famous for his book and judging but also he is the first breeder in the UK to breed a number of new colorbred mutations including satinette, topaz, onyx, eumo and cobalt. Geoff presented an informative seminar focusing primarily on the Cobalt and Jaspe mutations.

The Cobalt mutation is strikingly black and luminous but at first glance it might be confused with a classic melanin bronze. The cobalt hypermelanism mutation disperses a melanin veil effect over the lipochrome that occupies the outer edges of both sides of the feather giving the bird a striking darker black color. The phaeomelanin (brown) which is commonly express in the feather is no longer visible resulting is a clear, dark color and smooth ground color with maximum dark eumelanin. Geoff remarked that an onyx cobalt is the closest thing today to a black canary!

The cobalt should be luminous, especially evident in the intensive feathering and not dull. Selective breeding of these birds has resulted in a loss of all brown producing genes because of the optical blue factor or perhaps the Azul factor which he is currently studying. The azul factor is like a predictable optical blue, shiny and beautiful and never dull.

The feet of the cobalt should be dark in the bronze cobalt just like in a classic bronze. Classic bronze typically show lighter feet the second year but at this time some cobalt may have lighter feet, a fault, their first year.

Geoff remarked that "Beauty is in the Eye of the Beholder and his personal favorite is the mosaic red agate cobalt!

Geoff explained that Cobalt is a recessive mutation and follows the standard laws of Mendelian inheritance for a recessive mutation. For a bird to be phenotypically (visibly) cobalt it must inherit the cobalt gene from both parents as it only shows when the bird is homozygous or in other words when it has two cobalt genes, one inherited from each parent. This inheritance pattern is seen in a number of colorbreds such as opal or recessive white etc.

In this above example, a visible cobalt is paired with a cobalt carrier. This results in 1/2 of the offspring being visibly cobalt and the other 1/2 being cobalt carriers.

When two birds are paired that are neither visible cobalts but both carry the cobalt recessive gene as shown in the above example, 1/4 of the offspring will be visible cobalts and 1/2 cobalt carriers and 1/4 non-cobalt carrier.

A real highpoint of the seminar was when Geoff demonstrated the distinction between the intensive classic bronze and the intensive bronze cobalt which is easily seen by simply turning the birds over and examining the vent area. The classic bronze shown on the bottom, has considerable red lipochrome color on the underside while the Cobalt picture on the top is black clear to the vent due the super imposing of melanin pigment over the lipochrome on the feather edges!

Geoff briefly talked about the Jaspe mutation. In contrast to the cobalt recessive mutation, Jaspe is a dominant mutation and therefore is seen when the bird has one gene (heterozygous) from one parent called single factor and resembles a greywing with a clear area on the flight feathers or when the bird inherits one Jaspe gene from each parent (homozygous) called double factor and is the purest form but resembles a poor opal with a dark diffuse gray. The double factor is a co-dominant autosomal (non sex linked) inheritance pattern. Personally of about 200 Jaspe that he has seen, he only liked one and does not think this mutation, unlike the beautiful cobalt mutation, will become popular.

After the seminar, I ask Geoff if there was an Internet site where we might see more of these mutations. He recommended a dutch site I learned that it is best to google deschinkel rather than to call up the web site directly because when you google and then select this site, you have the opportunity to double click on the parentheses side remark which says translate this site so that it will automatically come up with an English translation. Once on the site, go to the lower right hand corner and click on all birds. I have really been enjoying this site.

When I went to the DKB show in Germany in January of 2008, I saw a long three tier row of probably 200 cobalts in all the melanin and mosaic variations. The high number of cobalts is likely due to its origin in Germany. I was really taken with one cobalt in particular the beautiful slate blue classic so beautiful because it has no brown! And of course I also appreciated the cobalt melanin mosaics too!

Jerry Zak and numerous exhibitors took the opportunity to have Geoff comment on particular birds after the seminar!! He was available to any exhibitor to comment on a bird or make breeding recommendations on how to produce better birds! Thanks so much Geoff for sharing your knowledge with us!!

People often wonder why exhibit and the answer is obvious to breed better birds and enjoy the friendship and experiences of other breeders!


Panos said...

Is it an autosomatic or a sexlinked recessive mutation??

Linda Hogan said...

autosomal recessive