Inbreeding is a subject which does not exactly stir up very pleasant emotions in humans. We immediately associate this work with incest and the governing laws against it and also of handicapped children which result from these offences. It is possible that a certain aversion to it is inbred in us, because there is a definite inhibition in mammals towards mating between parents and children and between brothers and sisters. It is quite possible that this inhibition has been bred into us from our animal forefathers.
No wonder then, that the Exhibition breeder is in two minds about inbreeding. On the one hand, he always hears and reads that a breeder can only achieve the desired features in his stock of birds through inbreeding and on the other hand there is the warning inner voice. Every now and then he might read an article in a magazine in which he is strongly advised to "keep his hands off" inbreeding, especially if he is a Novice. This, he reads, is a very dicy business, which calls for great breeding experience and is therefore unsuitable for a Beginner. In the same magazine, however, he will find an article claiming that he should build-up a "breeding-stock" or a "breeding-line" with its own characteristics, and to stay within the bloodline when pairing his birds. The contradiction of these arguments must have a very confusing effect on the inexperienced breeder. It is no wonder that we hear comments, such as the one I heard the other day from a breeder friend, after a long discussion on inbreeding. "Incest in humans is rejected and forbidden, so therefore I don't practice it on my birds". In conflict his inner voice won in the end, but unfortunately my friend was wrong.
In this article I would like to try and put down my thoughts on the problem of inbreeding in show-budgerigars, without discussing complicated scientific theories (which often dissuade readers from reading on).
Let us take it as being the mating of two individuals, more or less closely related to one another. Sometimes a difference is made between different grades of inbreeding i.e. incest-breeding, inbreeding and line-breeding, according to the closeness of the birds. However, that brings with it the problem of drawing a lien between the different birds and does not basically get us any further. Even in scientific terms this division is avoided. The scientists work according to a standard which marks the grades of relations.
Some readers are perhaps still under the misconception that inbreeding is a breeding method designed by men to achieve their selfish aims in the breeding of animals and plants. Even some books proclaim that inbreeding hardly ever occurs in nature. This is absolutely untrue. Not only a third of all cultural plants, but many wild plants reproduce themselves entirely, or mainly through self-pollination, which is incest in the truest sense. Many hybrids in the animal world practice self-fertilisation. Animals who live in a higher social order have a natural inhibition to inbreeding (which is limited mainly to parents and brothers and sisters), but they do mate between related individuals.
However, other mechanisms ensure that an exchange between the different groups takes place, so that "fresh blood" is continuously introduced.
I merely want to prove to the reader that inbreeding is not unnatural and with that I feel it has lost a lost of its bad reputation.
How did the show-race develop in the first place? Its relatively short history started before the Second World War in England, but only a few birds survived these bad times to become the ancestors of all the existing show birds of today. This success in bringing out the show types was only possible through inbreeding. Only in that way can new mutations be fixed within a stock of birds, and the desired positive gene-combinations reached and reproduced quickly. The improvement of the show bird is, and has always been, a continuous process during which you cannot manage without inbreeding.
When the first show-birds came to Germany, we had to practice rather close inbreeding. This was due to the low number of birds available, because the pairing of native birds proved very soon to be fruitless. Therefore, the few "Englishmen" had to be crossed with their own offspring.
The effect of inbreeding generally means that the relationship between the birds moves closer together so that the characteristics within the stock become more uniform. This uniformity is strengthened by a process running parallel to it. "the breeder carries out the selection among his bird families". He excludes some from further breeding due to lack of quality; to others he gives preference. Apart from that, every region has one or more successful breeders whose birds are especially in demand. Wherever you go, you hear one particular name as being the supplier of outcrosses. These breeders get their own stock of outcrosses over several years from the same English breding stock. All this leads to a uniformity of the characteristics within the showbird.
It is therefore a kind of Utopia if one believes a breeder could start from zero, i.e. with genetically completely different birds. This is in fact never practiced. A Novice will buy a few pairs from a breeder. The latter would probably vouch for the birds being completely unrelated by blood, and this he firmly believes, as by this he means they are not brothers and sisters or even half-brothers and sisters. However, if you go back over their breeding records, if these are available, you would find an astonishingly large number of joint ancestors of both partners in a pair. This fact is often confirmed to me by breeders who decide to start keeping a stock-card for each bird. On the back of this card you would find the ancestry-table for the bird. The surprise is usually great when the breeders find that a small number of extraordinarily good birds appear again and again, and sometimes more than once, on a card. Only then do they realise how often they themselves have paired related birds with one another. With this method you could probably make even those breeders who usually proclaim that they would never practice inbreeding, aware of their error!
In reality this means that breeding show birds without inbreeding is not practicable. The breeder can only determine the degree of inbreeding which he feels is justifiable. However, he should keep an exact breeding record, unless he has a phenomenal memory. it is said there are breeders who memorise the ancestry of their birds over 3 generations. I can hardly believe that, but apparently I was born with a sieve instead of a brain!
Up to now I have only talked about the necessity of inbreeding in Champion quality breeding. It is time that I turned to the dangers connected with inbreeding. These are collectively known as the "inbreeding depression", which comprises a host of complaints which very often occur as a result of close inbreeding over a period of several generations. Examples of these are
Decreasing fertility.
Lowering of resistance against climatic influences and diseases.
Stunted growth.
Decreased body-height.
Shorter life expectancy.
All these symptoms do not necessarily occur at the same time, but the closer the inbreeding, the heavier these symptoms of degeneration will occur. However, these inbreeding depressions do not necessarily have to occur in very case. It all depends on the gene-combination in the original birds or plants with which the inbreeding was started.
Wild animals in this respect have a much better starting point than domestic animals, who have been in man's care for thousands of years. The reason for this is that wild animals have already undergone a strict natural selection before the start. Since the budgerigar is a relatively new domestic animal, it must have been in a relatively good position when show breeding started. All the same, the inbreeding depressions cannot be overlooked. If anyone does not believe this, then he should just let an old experienced breeder, who started his career with the breeding of "pet budgerigars" after the first post-war years, explain to him the difference between such mongrel budgerigars and the show birds of today. This applies in respect of fertility, resistance to disease and life-expectancy. The show budgerigar is a perfect example for demonstrating inbreeding depression. It just seems that we have got used to these conditions and take it as being normal.
This brings us to a very important point, the question in each case of exhibition breeding, is what degree of diminishing fertility and lower disease resistance can be tolerated? Budgerigar breeders obviously accept the present conditions of the show bird but how long will this condition hold? Industrial breeding would certainly not tolerate this degree of inbreeding depression.
As far as I can see, however, the condition has not worsened within the last 10 years. This could have two reasons. It has been observed from inbred families of plants and animals, that after an initial rise in the symptoms inbreeding depression as a result of several generations of close inbreeding, no worsening of the situation occurs. The second possibility could be that breeders have simply learned how to deal with inbreeding depression. I am included to believe that it is a little of both factors.
Any type of inbreeding is changed into something negative if its counterbalance (the selection) does not come into effect. In this respect we find a decisive difference between what is happening in nature and in the breeding procedure. In nature the selection-process begins simultaneously in all parts of the body, with all its physical, metabolic, physiological and behavioural characteristics. If any decisive changes occur in any of these areas, which have a negative effect on the whole, then this individual will fall victim to the selection process, i.e. it will not be selected for reproduction and can thus not pass on its negative characteristics to its offspring.
Thus the selection process ensures the strength for the survival of the species. In hobby-breeding man takes the role of the selector. he sets himself a breeding-aim, i.e. he selects certain characteristics and tries to change these according to his sense of beauty. For instance, we have up to now tolerated the diminishing fertility of show birds. One could almost say that we have practised negative selection. To prove this, here is a well known example. An exceptionally good and successful cock proves to be a breeding-failure, due to a congenital behaviour defect. What should the breeding do about this? He offers him, one after another, a whole "harem" of young hens, in order to perhaps once catch him in a strong mood and to find an egg in the box. The owner is delighted to have bred a chick from this highly thought of cock and feels in the end that he is a great breeder.
In reality, he should have thought about this matter very seriously. One could interpret his actions that his aim was to create a reproduction weakness. He has acted exactly the opposite to what he should have done. he ensures that this degeneration symptom is continued throughout his stock, and this process is speeded up through inbreeding. However, he tolerates the loss of vitality in his stock because through his action the quality of his stock might be improved, and the judges only take note of the characteristics of the single bird on the show bench. Experienced breeders will test the small number of offspring of such reproduction-failures, to see if they suffer from the same defect. If this is the case and heredity is a possible cause, then they will remove this family from the stud.
An unusually high number of infectious diseases occur in one particular family of a breeder's stock. Other birds are sitting around looking sickly and suffer from anorexia, and still others are constantly moulting and are rarely in good feather. However, as this particular family happens to breed the best show type, the inexperienced breeder will try with all sorts of pharmaceutical products, to prepare at least one of those birds for the show, whereas the correct measure would have been to "clear the decks" and get rid of the whole sickly family as soon as possible.
I could give you a number of other such examples, which by the way are not fictitious, bat are taken from my own, often very painfully gathered, experience. if the reader has experienced anything like this, then he is in very good company. Just listen to discussions between breeders and you will find my opinions confirmed. A little while ago, I even overhead someone saying, he was going to pep-up his tired cocks with hormone injections, in order that they may perform on last act. If that kind of thing really goes on, then good luck for the future!
These examples show the dilemma between duty and inclination, into which the show-breeder is so often thrown. The fact that only a strict selection will provide the counterbalance against inbreeding depressions must be his only guide in making a decision in these cases.
The exhibition bird is the product of constant pairing of more or less closely related birds (i.e. the individual show birds of today already display a rather high degree of relationship). In the face of this fact, the damages caused through inbreeding, which ar undoubtedly present, are still tolerable. At least they do not yet endanger the survival of the show bird. The demand for the discontinuation of inbreeding is not practicable. It would also be contrary to the proven rule that one should stay in the "bloodline" with crossbreeds. The problem lies not so much in the practice of inbreeding, but in the lack of selection. Most of the symptoms of inbreeding depression do not have any influence on the show quality of a bird, i.e. they are only secondary in judging. Strict selection, however, is the only countermeasure for degeneration symptoms. It is therefore up to the breeders alone, as to whether the show bird will survive or not. Apart from selection, a sensible breeding method (i.e. not close inbreeding) and the establishment of an ideal type is necessary, which is based on a viable specimen.
There are signs that in future a kind of selection between the various breeders will take place. Word will get about, as to whose birds have good show quality as well as good reproduction rate and immunity against infection. It is therefore in the interest of each individual breeder to look out for these hereditary characteristics. To come back to the heading of this article without inbreeding there is not budgerigar breeding at all. It is entirely up to us whether this will be a curse or a blessing.
Do not worry about inbreeding. Observe the following rule: Avoid at all cost close inbreeding, e.g. the re-crossing of offspring with their parents, or brothers and sisters, or half-brothers and sisters. Try to match up pairs, within the frame of your breeding programme, in such a way that the degree of relationship is held as low as possible. The closest relationship of a pair should be cousin with cousin, or similar.
Certainty about the relationship of a pair can only be achieved by keeping an accurate breeding record. never5 rely on your memory.
Be extremely critical in judging your birds and be aware of any signs of inbreeding depression. Carry out strict selection and avoid desperate attempts to force offspring from a bird with a reproduction weakness. Pay attention to the state of health of your birds. Do not try to save seriously ill birds by means of veterinary or pharmaceutical help in order to continue breeding with them.
Do not miss the right moment when crossing becomes necessary. Make sure that the degree of relationship among the birds in your existing stock is as low as possible.
Do not hold your birds or the seller of the birds responsible for any difficulties which might arise. Rather think about what YOU might have done wrong.
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