York  Budgerigar Society

Inbreeding with birds

The principles of inbreeding are applied somewhat differently to birds compared with the method of their application to animals—that is with the exception of poultry. In the case of pigeons, budgerigars, canaries etc, the youngsters are produced from pairs, whereas, of course, with horses, cattle, dogs, rabbits etc. one stud male may be mated to a series of females within a comparatively short space of time, and in poultry one cock is run with a number of hens in a breeding pen. This is the reason why I have decided to write a separate chapter on inbreeding with birds, although the principles 1 shall enumerate are equally applicable to animal breeding.

To repeat what I have said in Chapter I, the object of inbreeding is to produce in excelsis the good properties of the birds which are being used, and avoid, as far as is humanly possible, intensifying faults or constitutional weaknesses.

By bad inbreeding one can with similar facility fix faults as by good inbreeding one can fix desirable features. Thus inbreeding may be said to be a two- edged sword, and it is essential to use one edge only, an ability not difficult of accomplishment if the owner follows the advice given in this book and uses common- sense.

Selection and elimination.

The golden rule of inbreeding can be expressed in two words—selection and elimination: selection of the right mates as indicated by appearance and pedigree; ruthless elimination of any bird that is for any reason undesirable.

The outcome of an inbreeding plan will give satisfaction or dissatisfaction according to the quality of the birds used in the breeding team each season—that is the quality of the related birds mated and their suit- ability to each other as mates, judged by both appearance and pedigree.

Close inbreeding must never be undertaken unless the fancier is convinced that the birds he uses are themselves possessed of the qualities which he desires to fix in his family; and he must assess their merits not alone on their appearance, but on his knowledge of the appearance of their ancestors.

In breeding livestock pedigree is almost as important as external properties. All families have their good points and their bad points. The best families have the fewest faults; the worst families have the most faults. I am not interested in the worst families.

When laying the foundations of a strain it is desirable to begin with a few pairs of birds of the best possible quality, those with few failings and obvious pleasing features. They need not necessarily be big winning specimens purchased at very high prices, but they must be at least what we fanciers describe as good reliable breeding stock, possessing among them all the desirable points of the breed and few bad ones, of which they will have some, as I have never yet seen the perfect bird or animal. But the weaknesses should be in minor points only; major failings should not be tolerated. The moral is to buy the best birds you can afford at the outset, and have few pairs of really good ones rather than more pairs of inferior ones.

Making a cake

I will repeat the analogy which I gave when I lectured on breeding at the World Budgerigar Convention, held in Harrogate in August 1954:

If a housewife is to make a cake she must have the right ingredients or the cake will not be a good cake. More than that: she must mix those ingredients properly, and it is the mixing which is, when applied to livestock culture, so tremendously important.

The good ingredients in our cake are the birds with which we start. The mixing is the selection of the mates so skillfully that in the course of time we have a strain, which breeds winners with regularity.

But in our cake mixture there will be some ingredients which we do not want in our finished cake. One can eliminate these by inbreeding linked with strict elimination. In the early stages of the carrying out of an inbreeding plan there will appear youngsters which display faults, and are themselves inferior to their parents. The faults are the family failings not necessarily to be seen in the parents, but carried by them latently.

It is because of the appearance of such youngsters as these in the early stages of inbreeding that so often inbreeding as a practice is criticized, whereas it ought to be praised for this very reason. If the parent birds had not been related the failings might have remained latent indefinitely, whereas they have now come to light and can be eliminated.

The youngsters from which the fancier will breed will be those, which are representative of the best qualities of the family—those that are cast out representatives of the worst features of the family. Inbreeding has brought the dross to the surface.

Continue with this process of segregation, and in due course you will have birds which carry hidden practically no faults and which are of good appearance themselves, and which, therefore, are capable of breeding high-class progeny. They are indeed as breeding specimens what they seem to be, as distinct from a bird which looks equally as good, but which is inferior as a breeder because it carries serious latent faults. Such a specimen as this is the frequent result of an outcross. To put it briefly and simply, inbreeding produces stock, which is homozygous for its own good properties—outcrossing more often than not stock, which is heterozygous.

Inbreeding does not create

Inbreeding itself does not put anything in. It does not create either good points or bad ones. It only makes the best of what is there. Hence the need to have all the good points (the ingredients of the cake) at your disposal, with the object eventually of condensing them all in the best birds you breed. The specimen that has them all, and as near none of the failings as makes no matter, is one of those outstanding individuals, which become famous.

To inbreed with poor birds would lead to the production of a strain of inferior quality, even though the birds bred would all be of one general type because of the effect of inbreeding. The successful inbreeder produces birds all with a family likeness, but they are of high quality, not mediocre.

Later in this book I shall give examples of livestock owners who have achieved outstanding success without introducing an outcross at all; and there are some who aver that an outcross should never be necessary. Enthusiastic as I am about inbreeding, I cannot entirely subscribe to this opinion, and I do not dogmatically assert that no one should ever introduce into a stud an unrelated bird, in spite of the risks attendant on outcrossing. The need can arise if the owner has some good quality lacking in the birds with which he commences to found a family.

In my own experience, however ruthless the elimination and meticulous the selection, there can come a time when the inbreeder notices that a certain failing is observed rather frequently in his young birds. This does not always happen, but it is an occurrence, which has to be dealt with when it does. And the only method is to bring in an outcross in the way which I shall describe in Chapter VII, Outcrossing.

Degree of relationship

When inbreeding with budgerigars or pigeons (of which I own studs) I am not so concerned as to whether the relationship between the members of a mated pair is near or far as I am with the suitability of the two birds as mates. I don’t deliberately breed from very closely related birds because they are closely related; I prefer a rather more distant relationship if 1 can achieve my object. As a matter of fact, after a few seasons of skilful inbreeding one can be so sure of the high quality of the pedigree of each member of the breeding team—so certain that there are no undesirable latent properties—that a point is reached when pedigree can almost (not entirely) be ignored and mates selected by analysis of visible qualities only.

I am often asked if there are any particular relation- ships which I favour, providing the two birds to be paired satisfy as regards their appearance. I can only answer this in a general way, as will be understood in view of what I have said in the last paragraph. I like uncle and niece, aunt and nephew, cousins, father and daughter, mother and son, grandfather and granddaughter, grandmother and grandson. I particularly favour half-brother and sister when the parent of both is a bird of outstanding merit.

I never mate brother and sister unless the two birds are of exceptionally high quality. The offspring of brother and sister can only have in their genetic composition the characteristics of the two parents reassembled, and you are not likely from such a mating to produce a bird better than either of its parents. On the other hand, a young bird bred from father and daughter, for instance, can have a double dose of a particular desirable quality carried by the father, as I will explain more fully in Chapter V.

C A House in Inbreeding stated that a fancier should concentrate on improving one property at a time until he has covered all the points and produces specimens approximating to perfection. To use his own words, he said:

‘Build up the fabric bit by bit. My experience is that you cannot reach a certain point as quickly if you attempt to do it all at once as you can if you make slow and sure progress by doing a bit at a time, and this, I know, is the experience of our most skilful breeders.’

Realizing that if this advice were adopted it would mean that the producing of stock of the highest quality would be such a lengthy process that no one could happily contemplate it, when I revised Mr. House’s book I made the following comment:

"I think Mr. House’s advice in regard to dealing with one property at a time was not meant to be taken quite literally. Experience has taught me that if inbreeding is skillfully and systematically employed one can, season after season, improve all the properties. If a breeder were to concentrate on one particular quality to the neglect of all others, it would obviously take very many years to produce specimens good in all points. And I know that when Mr. House wrote inbreeding he did not really intend to convey the impression that one property only should be dealt with at a time, but what he did wish to convey was the necessity when selecting mates and formulating a breeding plan of giving priority to that feature in which the strain is weakest. Later in his book Mr. House supports the view which I have here expressed."

Patience is needed

Many young fanciers are in too big a hurry to breed many winners. They anticipate establishing a family of merit within say a couple of seasons. While they may breed a few winners in their early days, they must not expect to own a strain of their own capable of producing many first prize birds, and almost every bird they breed itself a potential parent of winners, until three or four seasons have passed. They must have patience. They must carefully and skillfully build up the edifice they visualize when they start. Then in due course they will have their full reward. As a general statement, I would say that the period of time taken in reaching the objective is governed by two factors of equal import—The quality of the foundation stock, and the ability shown by the breeder in selecting and eliminating.

There are divided opinions as to which is the more important member of a pair, the cock or the hen. Broadly, my view is that they are almost of equal importance, but if I have a leaning it is in the direction of the hen, though according to genetic teaching, one sex has no more power over the quality of the offspring than has the other sex.

Why then have I any preference for the hen as a breeding force? Am I illogical? I will try to analyze my own thinking about this matter. The hen is, as it were, the soil from which the plant (our young bird) grows. And the strength of the plant is governed to a great extent by the quality of the earth from which it springs. To carry on with the analogy, if the hen is strong and vigorous with her inherited good features developed to the maximum (in short, she is good earth) it automatically follows that her babies will them- selves have such constitutions, and that the good qualities which they have inherited will develop to the fullest possible extent.

In considering this angle of the subject it has to be appreciated that good points inherited do not always show in a bird or animal as fully as they would do if there were no impaired development, and in this context I am not referring to that obvious impaired development due to illness or malnutrition, but to the same circumstance in a much smaller degree attributable to a prenatal or congenital weakness consequent on a similar condition in the dam.

This is not dogma, it is theory, but it is supported by my observation of many studs of birds and animals in the half-century in which I have been interested in livestock.

Almost invariably have I observed that a breeder who owns females inferior to his males makes little progress, whereas I have seen success achieved when the males have been of a little lower quality than the females.

In this connection, I notice so often a bad mistake made by budgerigar fanciers in particular. They buy high-class cocks—probably at shows where they have red tickets on their cages—and then, perhaps late in the selling season, they try to purchase suitable hens to mate to them. Very often the hens are not so good as the cocks, and the youngsters that are bred are disappointing.

Foundation birds

Sometimes we discover that we are the owner of a bird which is exceptionally prepotent. For the sake of illustration we will assume it is a cock. It may not be one of our big winners. It may be inferior in exhibition or racing qualities to its own brother, and yet it breeds youngsters of surpassing merit. In fact, it is a specimen in which all the good properties of its family are embodied and it carries no failings either visible or hidden. It is completely homozygous for all that is good in the breed of which it is a member. Even when mated to inferior hens, it begets good looking youngsters, though it should never have a low grade hen as a mate for this reason: The young birds bred from this invaluable cock and comparatively poor hen, although they may be good performers either in the show pen or in the air, cannot be expected to be good breeding stock because of the unavoidable influence of the dam on their genetic constitution.

Now this prepotent bird, which probably never breeds a youngster that displeases, is what can be truly termed a foundation sire.

When once the bird breeder discovers that he is the owner of that invaluable, one-in-five-hundred individual, a foundation sire (it can be a dam) he can establish a line within his own inbred family by breeding daughters and grand-daughters back to the father, or the father’s best sons, grandsons and so on—in fact, always going back to direct line descendants of the foundation bird on which the line is being established.

This brings me to the suitable point at which to end this chapter and pass on to inbreeding with Animals, because to the animal breeder the use of foundation sires (sometimes dams) is of the greatest importance.