Duck Colour Genetics
Book Review by FM Lancaster
COLOUR BREEDING IN DOMESTIC DUCKS by Mike and Chris Ashton More info
In my early days of duck breeding in the 1950s I was always very envious of budgerigar fanciers. Based on earlier work done by Dr H. Duncker, the Budgerigar Society produced a booklet entitled ‘Budgerigar Matings and Colour Expectations’. It contained lists of all the known colour genes and details of nearly 2,000 matings designed to produce every possible colour and pattern combination. With Mike and Chris Ashton’s new booklet, duck breeders now have their very own breeder’s manual.
Most of the early work on duck colour genetics by George Jaap, R.C. Punnett and others was published in obscure scientific journals and was not readily available to duck breeders. In spite of this, some of the early pioneers, like Mrs A. Campbell and William Cook, and more recently Will Bradley, Reginald Appleyard and Leslie Bonnett, managed to create some useful new breeds, with very little knowledge of genetics, by trial and error.
In the 1960s I tried to bring together all the known information then available on this subject. The difficulty was that the number of duck breeds and colour varieties extant in the U.K. was very limited. Hardly any new breeding and development work had been done since before the war because of food rationing, and no new birds had been imported from overseas because of wartime restrictions and fowl pest regulations. In the last 30 years the number of breeds has increased rapidly as a result of introductions from abroad and new creations. The Ashton booklet has made full use of this new resource and widened our knowledge of plumage colour genetics in ducks. The authors of this publication are eminently qualified for this task since they have not only made an intensive study of duck genetics but also have nearly 30 years practical experience of waterfowl breeding. The other innovation which makes this treatise so unique is the number and quality of the colour photographs, which are truly magnificent.
The booklet is divided into five sections. The first deals with basic genetics in an easily understandable form. The effects of all the known colour and pattern genes in ducks are then described together with their modes of inheritance and a list of breeds carrying them is provided.
The second section describes the appearance of the various breeds and colour varieties in greater detail under ten major headings. This is supported by spectacular colour photographs of ducklings, and adults of both sexes. I particularly liked the pictures of the wings of various breeds showing the specula and wing coverts etc. in great detail. Quite a few of the breeds are recent acquisitions from Continental Europe, and in this respect the work has a truly international relevance.
The third section on sex-linkage is understandably quite short since only two sex-linked loci are known in the common duck. Also sex-linkage does not have the same economic importance in ducks as in chickens and turkeys since vent sexing in ducks is relatively easy to learn. Section number four digresses slightly, and deals with some of Punnett’s early experiments with sex-linked brown dilution and explains its effect when combined with the two pattern loci, M+ and Li+
The last section, in terms of advice, is probably the most important of the whole work. It points out the major pitfalls encountered in producing new breeds and revitalising old ones. Most breeders know about recessive genes, but many are unaware of another ‘hidden’ group, hypostatic genes, which are prevented from expressing themselves by the presence of other (epistatic) genes at different loci. The two main epistatic genes in ducks are recessive white (c) and dominant extended black (E) which both mask the presence of most other colour and pattern genes. In fact, c is even epistatic to E when in the homozygous state (cc). The authors explain at length the difficulties encountered in using breeds carrying these epistatic genes. They also enlarge on the complex interactions between the two triple series controlling variations in the basic ‘wild mallard’ pattern. Throughout this section, they are to be commended for pointing out when their breeding results have disagreed with those of earlier workers, in terms of degrees of dominance and other gene interactions. With the wider range of modern breeds it is to be expected that some genes will behave differently against a different genetic background. In this respect they have updated our knowledge of colour genetics in the duck and brought it into the 21st century.
The final conclusion gives some very sound advice: Never produce a new breed or variety and release it to the public without adequate progeny testing to remove unwanted recessive genes. It is a great temptation on creating something new and exciting to release it too soon. This is unfair to other breeders and can only harm one’s reputation. The work ends with a chronology of reported mutations in Britain and a useful glossary and list of references.
I can thoroughly recommend this scholarly publication and suggest it should be an essential part of every ornamental, exhibition and even commercial, duck breeder’s library.
These books are available from amazon.co.uk