York  Budgerigar Society

As I have said earlier in this book, I am not one of those who asserts that outcrossing is never necessary, and I do not want my readers to get the idea that two unrelated animals or birds can never breed an outstanding youngster. Great winners have been so bred when the mated parents have ‘nicked’, which, of course, they sometimes do. But among those winners there have been many that have failed completely ever to produce offspring of merit.

Personally I do not outcross unless circumstances force it upon me. I know that there are cases where abundant success has been achieved without an outcross ever having been made, and to some of these I shall refer in Chapter VIII.

But even so, I contend that however skilful the inbreeder may be, however meticulously he may exercise care in avoiding fixing to some extent any faults, constitutional weakness, infertility or other heritable characteristics, sometimes after a period of inbreeding a failing unexpectedly appears. Suddenly some of the youngsters fail somewhat in a particular point or he may realize that he can’t make any more improvement in a certain feature, because none of the animals he has been using has had that feature sufficiently good for the breeder ever to produce it from his present stock.

Either of these occurrences must be accepted as a red light, and the owner must act without delay. The time has arrived for an outcross or semi-outcross to be made, the latter preferred if it will fully serve the purpose. For the sake of illustration, we will imagine that there is a decline in size in a breed in which smallness is recognized as being undesirable. We will assume that we are compelled to introduce an unrelated animal, or bird, as the case may be. The individual purchased must be a really big one, and not deficient in any of the other properties which we have well established in our own stock, though he may carry weakness in one or more of these latently, because of an ancestor or ancestors so failing, which, of course, is the reason why outcrossing is dangerous.

To counter the possibility which I have indicated we must convince ourselves, if that be possible, that the relatives of the outcross do not fail in other properties, and are also big birds-—in other words, that they are of very good general quality.

If the outcross comes from a home in which correct inbreeding has been practiced it will be all the more valuable and less dangerous, because it is more likely to be prepotent for its own good properties.

Blending the outcross

Having purchased the outcross (which we will presume is a male, though this is not a necessity) we have now to graft his good qualities into our own inbred family; and this is how we can do it:

1) Mate him to the most suitable female in the stud. Mate the best of the young females bred from this pair to her father. Their offspring will contain a double dose of their father, and when mated to other members of your own family should produce young ones which reflect the benefit of the outcross.

2) Mate the outcross to two females, thus producing half-brothers and sisters, which when mated together, will have children that contain a double dose of the outcross, and which in turn can be used with similar beneficial effect to those produced by method 1.

3) Proceed with the intensifying of the outcross’s good points (particularly the property, the improvement in which was the purpose of his being introduced) by mating the best grand-daughter back to her grandfather (the outcross). This system of breeding back to the outcross can be continued if the new blood brought in has had the desired effect.

4) Employ what is known as ‘grading’, which term I believe was first used in America in connection with a method of introducing a new line to an established line. This is described by Wendell Mitchell Levi in The Pigeon, the most informative book on this species ever published, as follows:

‘Outbreeding, sometimes called outcrossing, is the introduction into a pure line of a bird or birds of another breed or variety, in only one or a few matings in order to secure from the breed outcrossed upon some particular character desired, or to infuse into the pure line a dash of new blood for purposes of vigor. The progeny of the outcross are mated back into the pure line in successive generations until the percentage of blood of the outcross is practically negligible.

‘This method of breeding is useful in introducing into a pure strain some desired characteristic which it does not possess or in which it is weak, provided the characteristic is recognizable for the purpose of selection.

‘Grading or grading up is quite similar to outbreeding but differs slightly from it in the breeding programme followed after the first outcross. While in outbreeding an outcross is made from one’s strain upon a bird or birds, and the progeny mated back into the original strain, in grading an outcross is made (usually upon a male) and the progeny mated back to this male rather than to the original strain. Thus, in outbreeding, new blood is added in small quantity to the original strain, while in grading the original strain is gradually replaced by the new blood. Grading is principally used by cattle, poultry, and other breeders who have inferior stock and desire to raise the quality of this stock with the smallest possible cash outlay. So, a breeder of cattle possessing animals of scrub or only fair quality will have his females serviced by a fine bull of some desired pure breed (paying only for service) and breed back the progeny to this or a similar bull again, and so on for two or three generations, by which time the average quality of the herd is very definitely enhanced, and at small expense.’

Reducing the risk

In my own experience, particularly with pigeons, I have usually found it advantageous when I have decided

to make an outcross to bring in several new birds instead of only one, and for this reason:

Outcrossing is at best a risky business—not so risky when there is distant relationship—and it is always possible that the new bird or animal introduced may not ‘nick’ (as fanciers say) with any of the mates provided for him. Your chances of finding, a ‘nicker’ are, of course, increased if you are able to make several outcross matings instead of only one. When you are able to assess the merits of the youngsters, you may then decide only to continue to work with one of the outcrosses used in the first breeding season, and its progeny, it having given you satisfaction and the others little or none.

I have referred to outcrossing as a risky business, but this risk can be reduced if the bird or animal comes from a stud, the members of which are distantly or closely related to one’s own stud, but which have been reared in a different part of the country. It often occurs that this semi-outcross proves most helpful, especially in promoting what is known as hybrid vigor, usually associated conversationally with the complete outcross.

As an example of the good which can come from a semi-outcross I recall my own experience many years ago with light yellow budgerigars.

Mr. R J Watts, of Cambridge, had established a wonderful strain of these birds by judicious inbreeding. I purchased some from him, and so did the late Lady Bromley Wilson, of Milnthorpe, Westmorland. We both enjoyed much success. We both consistently inbred. Her light yellows were better than ours in some points; ours were better than hers in some other points. Lady Bromley Wilson died, and from her husband I purchased a number of the best birds in her stud. These were mated with our own light yellows, and the result was wonderful. Our progress with this variety of budgerigar was accelerated almost phenomenally.

A disastrous result

I also remember an outcrossing experience in our budgerigar aviaries, the result of which was tragic.

We owned a rather good team of light greens, pleasing in all properties, though in my opinion requiring improvement in head.

Another breeder who, by the way, was not in the least to blame for what happened, had a winning collection of light greens better than ours in head. His were quite unrelated to ours. So I decided to outcross to his family, but instead of carrying out the operation in the cautious and gradual way described above, I did it in a wholesale manner.

In the second breeding season after I had bought these birds practically all the youngsters contained both our own blood and the blood of the outcross, and they were a bad lot! I had ruined our stud of light greens, and learned a lesson!

Although the pairs, which I had mated in those two years, were excellent in so far as appearance was concerned, there was such a clash in the latent properties carried down from ancestors that it was impossible correctly to blend the two strains.

Those who adhere to the two (or more) line method only make semi-outcrosses, as I show in Chapter VI, unless it should happen that the need does arise to bring in a distinct outcross into one or other of the two or more lines.

Above I used the expression ‘hybrid vigor’. It is generally considered that when two unrelated animals are mated there is an increase in the constitutional strength of the offspring because of the unlikelihood of them both having the same physical defect, and, consequently, the vigor of one overcoming the weakness of the other. But this is by no means an invariable rule.