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Well, I have to say I didn't understand how you were going to keep your web site and articles confidential, but you
certainly have.  I must commend you on the idea and implementation.   I have been impressed by some, not all by any means, but some of the
articles and information on your site.  I have been breeding for many years and felt I would like to share my opinion on inbreeding with you,
and through your site, others.  It may be a little hard for some to swallow, but it is a summary of all of my years of breeding, inbreeding,
reading and showing.  I know that there are many who feel that inbreeding has achieved a very negative image, despite its value.  I hope
this article will make people think about their perception of inbreeding and spur people to provide answers to numerous questions that I have never had
answered to my satisfaction.  Please accept the attached article.


Different experts and authorities provide highly variable opinions on inbreeding and linebreeding.  I have always found it impossible to take many of these people seriously. Unfortunately, my experience has revealed that few people have the innate curiosity that drives them to find out how things actually work.  Inbreeding or linebreeding is not a mathematical pursuit or formula, except where it might be used to predict the possibility of change in a finite, imaginary population, for a quantitative factor (statistics).  It is not, for me, a complex sketch or diagram of related or unrelated matings.  It is not the simple crossing of brother to sister; cock to daughter or hen to son.  It is art.  It is feel.  It is at once instinctual and intuitive.  It is the compelling observations that a breeder makes about his stock's behavior and inheritance over many years. That knowledge and the relatedness of ones birds is so ingrained in a breeder that he can subconsciously pair the birds that have the greatest likelihood of producing the offspring he wants.

As I indicate in the body of this document, inbreeding is not memorizing a standard form and trying to emulate it as so many people try to suggest.  It is not seeking to identify and build on a sport or oddity or at least rarely, as sports or mutations tend to be discontinuous.  The real inbreeder is driven to develop a bird that exhibits desirable qualities, that is singularly identifiable, behaves well and is active and responsive.  More than anything else the inbred bird must display all of the characteristics that the breeder views as critical and desirable.  If in his or her eyes the "new" bird looks good, then it will become a new standard of its own, and others will come to accept it and want it or reject it out-of-hand.

Inbreeding is the simple and aesthetic act of crossing related stock to produce the best. This is accomplished by selecting for those transmissible and desirable properties, that are the province of only a very few outstanding individuals, and ensuring these traits accumulate within the offspring.

The following position is based on my own observations and reading of numerous articles, both pro and con, on inbreeding.  You may not like my position, I guarantee you will not like my generalizations and you may not like my approach and interpretation.  If you do not want to read something that is controversial and intriguing (unfounded to some of you), you may as well stop now.  The anti inbreeder will resent the information and inferences present here-in.  Biologists, Taxonomists and Ornithologists may find it farcical or erroneous, while Evolutionists may say it is so general in its sweep of suggestions and questions that it is unworthy of response or notice.  However it is received, I believe the questions need to be addressed, or the stories of negative long term effects of successful inbreeding will continue, despite being premised on poor results, excessive selection, human morality or misunderstandings, as I explain later.

A personal and descriptive visual explanation of inbreeding excess

To describe excessive species selection in an understandable way, I like to think of an upside down triangle, where the triangle is comprised of a series of minute horizontal lines, much like pixel density, which generates a digital image. Each horizontal line comprises a single variety or breed (one line per breed or variety).

Varieties continue to be distilled, from a diminishing gene pool, until the inverted apex results in a breed that survives or dies based on whatever genes are eventually left at the end of a long, long selection process. Is this the denouement of the species, if indeed so much of the germinal DNA exists above it ?

Even the most adamant anti inbreeder must recognize that selection is a continuous process in wild species and many of the changes (gentic gain or loss) which occur will not be noticed, even by the most meticulous observer:  That's life in the wild.  Variation enables the species to undergo slow or rapid alteration or change to enable adaptation to a shifting environment: thus continuance of the species may be optimized.

Some would suggest that there should be clear or empty lines in a hypothetical triangle, presented as a solid object, as these clear lines would serve to represent or explain evolutionary or inbreeding dead ends.  I would contend that the triangle appears solid, despite full recording of inbreeding and evolutionary dead ends. The number of viable varieties and genetic permutations far outweighing the encountered or unrealized dead-ends, whether natural or artificially selected.

All species have a finite number of genes, that is indisputable.  The question is: how many genetic / phenotypic permutations are viable, given that a theoretical core of genes are essential for vitality, vigor, fertility, fecundity and longevity ?  If we look at a species that reproduces itself, forms a clear phenotypic presence and has normalized variation (around the arithmetic mean) within the population, how does that description differ from a variety or breed ?  A heterozygous individual, as I have come to understand it, merely indicates that a particular gene has been revealed or expressed through some process, and represents substantive enough change to warrant notice.  Remember, this mutation is not added, but revealed from the "normal" genotype, suggesting that the species carries the gene, but that the gene is in a masked, incomplete or recessive form, waiting to be uncovered or used in a survivalist adaptation.

A wild species or population has (requires) a great deal of potential variability present within its genetic make-up, and consequently a potential for numerous spontaneous presentations of discontinuous mutations.  Given that a variety also has a fair amount of variability surrounding the remaining genetic material, it troubles me when people speak of the wild species being heterozygous.  If it was, there should be spontaneous presentation of mutations on a weekly or monthly basis, depending on the population's size.  Other than numbers, how does the varietal genotype differ from the wild stock, and is the wild stock truly heterozygous, or is it simply homozygous for those traits selected by nature which in turn masks other genes as in the breed or variety? How do people balance a defined heterozygous state with continuous variation or variability around a mean, when that very same variability occurs around a defined homozygous type ? Are we becoming too general with our use and application of heterozygous versus dominant types / species  definitions and usage?  If there is considerable variation from and around the population mean, which represents the recognized physical type, don't heterozygosity and homozygosity begin to overlap in meaning ?  Where does heterozygosity end and where does homozygosity begin?  Is a multigenic mutation heterozygous or homozygous for the traits? Are you becoming confused ?  I am.

Given that each line in the triangle represents a variety or selection, there is obviously a transmittal of genes, both good and bad, among each variety trending away from the species type.  After all, in lovebirds, we only really look at the color mutation aspect, although a few breeders may be seeking size, girth or something else.  In the majority of cases many of the factors we seek as breeders are not continuous. This means that the breeder may not be able to achieve a certain color blend or expression, despite the fact that we have seen many color selections and mutations in Budgerigars and Canaries.  It is the discontinuous events like structural mutations that breeders can work with and intensify among the offspring over time.  These mutants are essentially sports exhibiting some small change in form. Identification and breeding success (repeatability or improvement) depends upon the breeder's awareness of, or recognition of slight changes in offspring in his own aviary population.

Compassion & Breeding

Compassion is not something that the successful inbreeder or line breeder can afford and it may well be why so many inbreeders are despised by those who would effect to save every bird.  Furthermore, we repeatedly hear that breeders are selecting based on individual traits versus the population average.  This may or may not be true, although I would tend to believe it:  Breeding best to best is not a good maxim unless the breeder applies it properly.  I think most long-time breeders would admit that there is always a reversion to type (to the average shape and size of the population being selected), and that even following what we call homozygosity (prepotency) in the desired bird, there will still be significant variation within the population's offspring: not variation to the extent experienced in a large population, but individuality and variance in structure, color, internal workings, muscle, beak etc... .  In other words, even homozygous birds exhibit variability around the select "type", just as variation in wild type offspring occurs around the species "type" as discussed in previous paragraphs.

Failure to assess your stock, and merely selecting the best looking bird is a sure way to run into the problems encountered by most novice or curious inbreeders.  The inbreeder needs to work with the population average.  If a good looking individual does indeed prove himself, by all means mate him to your best hens, but if he fails in passing on his traits, replace him with a better bird (a bird that might not look as good, but passes on real benefit to the stock).  Every breeder wants to rush to the finish, but ensuring your birds are prolific, fertile and active is critical to running the race.  Checking the mean population improvement, instead of basing everything on the outstanding individual whose reproductive vitality may be less than desirable, will help to prevent the serious breeder from getting to far ahead of the process and heading full speed into a dead end.

Finally, I agree with many things said on this site, including the one that says it is a simple matter to for those opposed to inbreeding to make general, sweeping comments about the negative side of inbreeding or ignore it.  Unfortunately, it is impossible to dispel these perceptions when no one wants to discuss or educate others about the process and its pros, cons and myths.

Hybridism - a problem among species ?

While I understand the conservation and purity question surrounding this issue, I often have to wonder why we get so upset by the possibility of species crossing.  If species cannot cross, as has been stated on this site many times, there should be no offspring and no fear of pollution of the gene pool.  Therefore, the only concern that can arise is one of fertility among hybrid offspring; either with parental populations or between each other.  If hybrid offspring are fertile, either with one or other of the parental populations or with each other, there must be some undefined relationship between the "species".  If crossing can occur with little trouble and both sexes are fertile, can we really continue to identify the parent populations as separate species, and if we do, are we only basing speciation on phenotypes versus genotypes?  Improved DNA understanding and analysis would suggest we are burying our heads in the sand on this issue and holding to outdated tenants, despite information or results that point to the opposite of what has been and continues to be taught:  Why?

Each gene or set of genes which can be transferred from a different "species",  may enable significant new combinations to occur, within complementary and viable genomes, regardless of our taxonomic designations.  Given the enormity and potential associated with the number of gene interactions and exchanges available through natural pairing or artificial insemination (A.I.), there should be no surprise that breeders run into a number of dead ends, whether working with hybrids or strains.  Usually, failed seminal varieties, hybrids or breeds are selected, not by genes and performance, but by human compassion, which is  thrown into the selection criteria.  Animals that would not survive in nature, are not only saved and nurtured by people, but are encouraged to breed, thereby passing on undesirable gene combinations that can lead to the very problems everyone tries to avoid or attribute to inbreeding.  I don't want to say inbreeders don't have compassion for they do, but they are usually running a business that parallels the livestock industry.  The selection and intensification of blood in a line or hybrid is done because there is an undeniable and quantifiable economic benefit perceived at the end of the day, by the breeder, on top of the joy associated with developing something new.

There are obviously many more cases of natural hybridism being recognized among different avian populations today, than ever before: one of the primary reasons people are more frequently including "hybrid zone" potential in reports.  This implies that hybridism is not simply a concept derived by greedy or unscrupulous inbreeders, but rather a natural event that is successful or unsuccessful, based on chromosomal similarities and natural selection.  I do not believe any of us would complain to loudly if a breeder decided to cross their pallid roseicollis with a turquoise roseicollis or a blue personata with a green personata.  Why is this activity such an acceptable practice, and yet when we look at the word "species" attached to a group of birds showing the same phenotype in the wild (which implicitly suggests that chromosomes are dissimilar) any crossing or offspring production is considered inviable or an aberration. It is neither logical, scientific sound or pragmatic. Simply put, hybridism wouldn't exist if it couldn't happen or if nature had not planned for it somehow.  The benefits to species survival, from hybridism, given the need for rapid change are obvious.  Is the concern simply because we are referencing a known, defined natural form and we have a reluctance to see the form change or lost.

Artificiality is present in everything we do, from the saving of specific species at horrendous costs, to the re-introduction of species in the wane.  Choose any example you like, whether whooping crane, swift fox, black footed ferret, Giant Panda.  The focus is invariably on altering the food ingestion mechanism, the ecological surroundings and other things.  We talk about isolated populations that are inbred and more susceptible to cold weather fluctuations or some other aberrant climatic phenomena.  Why is this susceptibility considered so significant, the population was not selected for these swift and aggressive changes.  Those that die were ill-equipped for the sudden change, others ( the variability about the mean population) were lucky enough to survive.  We focus on species extinction/extirpation and trying to reintroduce them to the wild.  Man has created the selective pressure on these animals as surely as he has changed the face of the world and perhaps weather phenomena.  It is no surprise that we see wild birds adapting and beginning to forage successfully in urban jungles rather than a natural one: that is simply where selection has led.  We try to save a species, when we should be working to stabilize the ecosystem: if we wish to stabilize anything and prevent the inevitable progression of time and change.  Too complex some would say, but is it any less realistic to think that one can save a single "natural" species, where the environment and food source that the species in question was once dependent on has been eliminated by weather phenomena, catastrophe or climactic spikes?  It is the constant variability around the mean that would seem to ensure survival, not the constancy or fixation of a recognized form or type.  Loss of species will continue: don't doubt it.  It is an historic fact and indisputable. It will continue, either at a reduced rate or increased rate depending on global focus.  Does hybridization increase the chances of survival for "species"   My position is that hybridism is a positive activity interaction that strengthens the odds of gene pool survival, regardless of the commonly perceived "type" that may be universally recognized under prevailing steady state pressures, continuously applied by natural selection in a relatively slowly fluctuating environment, and a means to induce rapid change where rapid or catastrophic environmental changes occur.

The logical meta-question that arises is whether lovebird species named today may in fact be varieties of a much larger parental population, for they really appear to represent a homozygous form in their breeding, phenotypic reproduction and breeding.  Are some of the existing lovebird species actually evolutionary dead ends (without hybridization) because of natural over specialization (lilianae and swindenaria), which also threatens species survival in the event of a cataclysmic event ?  Major steps have been made with production in rare species,  but swindenaria is still a relative unknown, while the pure Nyasa tends to die at or during the molt, except, as I understand it, where a cross with other species has occurred in the background.  Is anyone aware of a mutation or physiological change in the pure Nyasa that enables the juvenile to pass through the molt and survive to adulthood?  If so, how does one know the birds are pure? If not, are these species so adapted to their historical territory that they are incapable of surviving in another environment.  How do adults survive and not offspring, and are offspring that die, the progeny of hybrid birds?

Pet Peeves and Irritations

I have become very irritated, frustrated and yes, even cynical about always having to hide my use of certain breeding activities because it will hurt or bruise the sensitivities of those who simply breed, buy and sell birds for economic gain, but do not wish to hear, see or be seen to show interest in anything akin to inbreeding. However, these same people are completely at home and even complimentary about linebreeding.  The honest practitioner will tell you they do not really know where inbreeding turns into line breeding or line breeding into inbreeding. It is refreshing to know that so many who do not practice either breeding method and resent inbreeding, are so comfortable with line breeding.  It baffles me that people can act in such a contradictory way. In my experience, inbreeding is the most useful method that we breeders have in the struggle to condense desirable genes in new types, variants or strains.

If inbreeding gets the job done - the breeder should use it.  If it is the best method to concentrate or intensify desirable bloodline (genes) - the breeder should use it.  If it results in a higher percentage of defective or deformed chicks, then the breeder should accept that as the cost for seeking the best in his stock or as a necessary evil in eradicating lethal or congenital recessives - and use it.

Realize, as many have stated on your site's web pages, that the dirt (minimal / maximal deformity) rises to the surface with inbreeding and can be overcome in most cases if managed properly by the breeder.  Inbreeding is the only way to reliably improve your stock, yet the majority seem to live in fear of it.  It is highly unlikely that those reading this article will not own or have inbred birds present in their stock.  Even going outside your own aviary for an "unrelated bird" of the same mutation, means that the bird you find will be a close or distant relation to your own bird.  Certain mutations tend to be highly inbred, initially, so you have acquired / paid for a bird that is most often the result of inbreeding (mutations tend to be recessive to the wild form and color and subsequently a relational aspect exists). It is also important to realize that the discontinuous nature of mutations does not enable the colors to blend well with the wild type, but instead separate out, based on dominant / recessive inheritance.

I might be so bold as to say that hybrid (transmutation) birds are probably more heterozygous than our own birds because of the need to constantly outcross to the best in the receptor species, to ensure the retention of the physical appearance of that species.  This is quite interesting, as it clearly implies that the hybridizer seeks the homozygosity of the color receptor species.  He does not seek a heterozygous genome, but rather a homozygous genome that enables the hybrid bird to be identified as a member of the receptor species (see: My favorite Peeve).

A hybrid species development or evolution tacitly implies the need for significant hybridizing and inbreeding between the parental generation or F1s depending on fertility ranges.  If begun by only a few pairs, a successful population will be highly inbred, despite the prolific nature and expansion of such a seminal group.  Is there a weakness or flaw associated with this process ? Yes, but nature has its own way of changing and selecting for successful species or varieties, that we are still trying to discover.  Whether you feel this is fanciful, or foolish thinking, double-speak, devoid of fact and substance or scientific scrutiny, the questions that ultimately follow are:

  1. How different are (homozygous or prepotent) varieties from the (heterozygous) wild type ?
  2. If varieties and wild types are identified by external appearance or phenotype, only small changes can have occurred in the variety - TRUE OR FALSE?
  3. If varieties have only experienced a few gene changes that impact color and behavior for a different environment (domestication) - how quantitatively different are they from the wild population ?
  4. What is the difference between varieties, breeds, sub-species, strains and yes, even the wild population?
  5. If inbred varieties are to succumb to inbreeding depression and loss of vigor, why is this not also true for sub-species and even the primary population, although admittedly the same effect would take much longer because of the larger population - However, even this is premised on a belief that the wild bird is more heterozygous than the variety -  I have read this in report after report, but have seen no mitrochondrial DNA evidence that would substantiate a substantive or significant statistical alteration in DNA chains among wild type species or their sub-species, let alone varieties or breeds.  What level of DNA  or genetic change is required to come to the conclusion that inbreeding leads to a path of eventual destruction ? What time frame are we talking about ?
Wild or Domesticated Parrots and Stock

Most people want to buy the pretty birdie or the colorful parrot in the pet cage  They smile and want their picture taken with a Macaw or Cockatoo. The children want the pretty budgie to hold still on their finger while they are photographed with it.  What is similar or shared between all of these birds ? All of them are inbred to some extent.  Some will say it is taming, training, treats and care that make them such pliant and wonderful pets.  Show me one wild parrot that will respond to strangers the way these "pets" do.  They are inbred, it is not simply handling or TLC, their whole response mechanism and behavior has been undermined or subverted by treats or other training devices.  Oh, it may be that the birds are not genetically inbred, but these birds have been selected for docility and lethargy, not for natural fire, aggressiveness, shyness or vitality.  The average bird lover would be shocked by the difference in behavior and needs of a wild parrot versus a domestic one, so let's take the blinders off for a moment and see that cage birds are usually either inbred or behaviorally altered to some degree.  It can be no other way, given the human desire to see or own new or unusual mutations, crosses or hybrids (non aggressive ones): birds that are calm and unflappable.

The reality is that the pairing population potential in cities or towns tends to be fairly limited when seeking partners for your bird.  If the bird is a combination color, the chances of inbreeding increase.  Yes, people can go and buy birds from a long way off, but depending on the extent of breeding and bird availability, the breeder is going to run into terrific expense and some uncertainty as to the relatedness of purchased and owned birds.  In small populations, inbreeding is inescapable.  It may be a milder form of inbreeding, but inbreeding nonetheless.  Can we really avoid it and do we want to ?

I'll go one step further here and say that inbreeding is a necessary mechanism for improving stock quality, not simply a good or an alternative mechanism, but an excellent one for the exhibition breeder.  There, I have said it, inbreeding is good!  And let any of you argue who may.  Good inbreeding will produce birds that are at least as good as the parents and in many cases better.  We breeders have been hijacked by a sense of moral prudishness with our birds, and by those who continue to advocate against inbreeding while they purchase or demand access to the results.  Those that are not courageous enough to take up the torch of inbreeding will never attain the ultimate breeding pinnacle, the desire of every serious breeder:  A strain of one's own and a bird whose conformation, color, vigor and fertility set it apart as a highly desirable acquisition (there is no escaping the economic compensation that can accompany a desirable mutation or variety).

 There are many who will advocate against inbreeding and state that they have never inbred their birds.  If they have never inbred their birds, I for one must state that they are not really breeders, but simply propagators of a mutation or species.  How do people who have never experienced the success and challenges associated with inbreeding form a knowledgeable position against it ?  From reading stories about fewer eggs, deformed chicks and infertility ?

If, a breeder has never experienced dead-in-shell, infertility, dead chicks, and either mild or severe congenital defects, I for one cannot say what he or she has been doing.  Inevitably, with many years of breeding, the breeder will experience these heartbreaks in the nest, over and over again, despite efforts to outcross his birds.   Inbreeding shortens the time frame for these losses, with correct breeding, and will reward the breeder with healthier stock and birds that are almost identical in size, color, and reproductive success. Are their immune systems compromised by the loss of congenital defect genes, or the unmasking of these lethal or troublesome recessives.  I don't know, but their very existence is a concern in any stock.  How much immunity is lost versus lives saved because of the extraction of a lethal gene or debilitating congenital defect ?

Myth,  Fact or Simply Unknown

An example of inbreeding and the many schematic breeding strategies that are available can be seen on the Sabong cockfighting page.