No to Hybrids ! ?
Introduction
I would like to thank you for having the courage to set up a site that deals with a subject, perceived by many, as highly emotionally charged: hybrids. Your pages are interesting and informative and makes one think about what they do have. I have found that people do not respond rationally when it comes to hybrids or dealing with any mixing of species. The end result of this attitude is that organizations fall into line and also try and refute a natural act that may have led to new species development.
When I talk to people about your site, all I get is negativism and quotes from other groups or experts that state that hybridism is the end of our species and could pollute the gene pool. When I ask them what gene pool, they do not know how to respond. When I ask them about the offspring of a mix, they state, with equal conviction that all lovebird offspring from different agapornis species matings are infertile. They are as adamant about this as they are about the negative impact on the gene pool, and little will get them to change their mind set.
Should we all say NO to hybrids and hybridism. If it would do any good, perhaps it would have been a worthwhile goal, but as far as I can determine we are well past that point. What does surprise me is the lack of interest from those who have been taught to despise hybridism, and see hybrids as a negative force. It is like the movie 10 Commandments, where the Pharaoh's dictum: "So let it be said, so let it be written, so let it be done" (or something like that), ends discussion and no further debate is required, warranted or desired.
What is the point of this article ? Do hybrids pollute the gene pool ?
The Gene Pool
Do hybrids pollute the gene pool ? The response of course, is another question: How can hybrids pollute the gene pool ?
A gene pool is the aggregate of all genes within a similar or like species. While the definition of species is recorded in different dictionaries, a thinking being must see that the definition is challenged by many of the activities pursued in the lovebird species. We know that in the pre-war years that many lovebird species were imported into Europe and that black-cheeked (nigrigenis) were mixed with black-masked (personata) and Fischer (fischeri) with Nyasa (lilianae). In all instances these crosses resulted in fertile offspring. We are talking about four distinct and different species, as classification analysts or ornithologists, would have us believe. Yet despite all the odds, these distinct species produced viable offspring (cocks and hens).
The peachfaced, madagascar and black-winged are all supposedly fertile, whether inter se or in backcross. We also know that a peachfaced by eye-ring results in fertile offspring, again inter se, but may also be fertile in a backcross. How can this be, if these are all distinct species, with equally specific and distinct gene pools. the only logical answer is that lovebirds share a common heritage. That the gene pool was, at one time a complete compilation of all of the lovebird species genes.
A monphyletic origin, some will scoff, has been ruled out for ages. However, no other theory matches the development of agapornis species like a monophyletic origin. This requires the identification of an alpha species: a species that comprises the majority of genes in all other lovebirds. Where is this species? We don't know. However, for so many distinct species to be able to mate and produce fertile young suggests a similar historic evolution or speciation path.
We know that people who came across the wide variety of canaries or finches in the world today, for the first time, would probably identify a number of distinct species based on body form, color and shape, versus the recognized varieties that have been documented and catalogued over the years. They would find that many of these canaries and finches would be fertile either in the "hybrid" cross or inter se. How would they explain this ? Distinct species having fertile young in mixed breeding ? Impossible? There must be a relationship between the various canary species and similarly, if dealing with finches, between finch crosses.
For some reason we do not think quite the same way when natural selective pressures occur over time. When birds are first identified in the wild, in different niches, they are presumed to be distinct species or sub-species, not varieties resulting from natural selection. Behavioral and morphological (shape, size color) responses are the result of niche selection, while sound or song change can result from beak or other morphological alterations. Are we looking at varieties within the lovebird clan, and a re-joining of separated genes to the primal gene pool with hybrids or something quite different. A hybrid look would be natural, as two clearly distinct varieties are being joined. Consequently, the offspring look different. Unfortunately, the common hybrid is often smudged or a bleary replica of one of the parents and therefore viewed as undesirable. However, when we cross varieties within a species, the hybrid offspring, while different from the parents, may turn out to be highly desirable and the link to hybrid ancestry (varietal cross) is ignored.
If the genes that separated or altered over decades, are re-introduced
to the primal gene pool, we have hybrids, but not hybrids that are held
in the same disregard as they are today. The gene pool is in fact,
not polluted but re-united. This inclusion or combining of genes
turn would enable greater speciation or adaptability in changing times,
as nature necessitated. A wider heterogeneous gene pool has always
been viewed as a preferable to a homozygous gene pool, where naturalists,
ornithologists or purists are concerned. The opposite is the end
result and desire of the mutation or transmutation (hybrid) breeder.
Impact of Hybridization on our Birds
As stated earlier, hybridization occurred in very many instances, whether intentional or performed in the hands of the novice. In the professional hands of a hybridist, the hybrid would be engineered to appear as one or other of the parental birds, over a number of generations. For the novice with and aviary, any cross may well have been bred back to clean parental types and consequently hide or mask the hybrid nature of the bird.
In many of the articles found on the net, their is obvious concern that once a bird has been crossed, the bird retains the new gene mix and is consequently downgraded as valueless to the purists. Unfortunately, there are few lovebirds, if any that are really pure out there today. We have decades of hybridism and selection for color under our collective belts, whether we performed the activity or not. Restrictions on imports and the movement of birds between continents does not imply better birds or pure birds, but more than likely, birds that have been selected for those characteristics seen as natural in the wild state. In other words we are selecting birds for an ideal that may or may not exist. Certainly in the show circuit, people are trying to Purify species that are perceived as rare, but we know that we cannot purify if indeed we have crossed in other genes, and the genes give us a particular color or form. In other words we don't really have pure species.
We know that there are few natural color mutations in the fischer and we believe that the dark and violet factors were transmuted (hybridized) to the fischeri species. In effect, any bird with violet or a dark factor is a hybrid. Deny it or believe it. As for new or real mutations, they are often suspect when a number of birds arrive on the scene all at once, when the first occurrence is not recorded or when one sex rarely hatches or survives. The subsequent rush to combine the new color mutation with other factors ensures that these birds too, are soon hybridized,
The Nyasa and the fischer were also crossed and gene transfer impacts may not be as clear in these matches, but certainly stronger hybrids resulted. Previous to this it was very difficult to keep and culture lilianae, as the young often died at the molt. Success with lilianae today is based on what ? Has the cause of early mortality in fledglings been identified? I haven't heard, but maybe.
Black-masked and black-cheeked were crossed without thought, as apparently they appear similar to the novice. Both of these birds are prolific, as is the fischeri. Short reproductive periods and numerous offspring undoubtedly contributed to the rapid spread of hybrid genes in these two species as well: Consequently the efforts today to purify the species, and efforts of organizations to encourage birds that look like the standard.
The peachface, madagascar and other species are certainly different from the eyering species, but the issues is how different and what degree of genetic alteration defines different species.
Does a preexisting condition of inadvertent hybridism mean we should throw away our birds? Of course not ! We deal with the situation and realize that a bird that is aesthetically or behaviorally pleasing will always be purchased and enjoyed by the owner. Shows are doing a wonderful job of bringing back a clean standard for the lovebird, but there is always equal if not greater demand for new colors, varieties and interesting hybrids.
The Challenge
Once a hybrid variety has been established, it is often hard for people not to cross the bird with another variety for a desirable factor or to improve or maintain the form. Unfortunately, every cross results in more hybrids, as the hybrid genes are passed on. Those that subscribe to once hybridized, forever hybridized, must also recognize that any cross between birds with a hybridized factor will result in transference of hybrid genes to the offspring. Thus many if not all of the eye-ring species are already hybridized or nearly so in domestication. Many people favor these smaller species, but are happy looking the other way when they buy these birds or are captured by the colors in the species.
Are peachfaced as completely hybridized as some of the other species. No. This species, like the madagascar and others have dodged the bullet in many ways, as they are more difficult to hybridize, but possible none-the-less. Why does this species have so many of its own mutations versus the other species. The peachfaced is easier to breed, according to some, and has been more accessible than other species. As well, the pet owner, will often not mind if their birds are closely related when matching pairs, although that may have changed over time. At any rate, close matings and observant breeders have increased homozygous genes and protected new color mutations and led to the establishment of new mutations.
Will hybridization lead to the extinction of species? Highly unlikely, in fact probably quite the opposite, for the following reasons:
Escapees
There is a lot of concern about escapees from domestication, but is there any difference where a wild species is transported to another country and released en masse into the wilds of civilization ? We know of many documented cases of wild lovebirds (masked, fischer, peachface and others) and other parrots released, where there are no natural predators, and they live to reproduce and colonize. The impact of these wild escapees should be just as significant, if not more so, than hybridization. hybridization, initially is usually well controlled and wasters disposed of. In a wild release, parrots can eat vegetation or food stuffs that feed an endemic species. There is tremendous concern about this, but it is one of the realities we deal with living in a world where people and cargo can move from country to country in hours. Hybrids are a small issue when measured against existing releases and their success.
If a population of agapornis roseicollis roseicollis establishes itself on the continental US, for 60 to 100 years, will it be called a new species, a sub-species or a variety? Will it adapt to the new surroundings such that its genome and beak alters significantly ? If it burrows a nest hole in cactus versus taking over a weaver's nest or building its own stick nest, is the behavior so different that it constitutes a new species ? How substantive would be the difference between the African and US population? Would crossing the African lovebird with the US lovebird lead to a hybrid ? Would they even be fertile ?
The escapees, if monitored, can provide incredible data regarding their adaptation to a new environment, any alterations regarding behavior or other cultural activities that differ from the original species, and changes in food acceptance and dependence and weather conditions. they are a wealth of knowledge and understanding, just as hybrids are when they prove fertile or fall in a range of fertility, from zero to fully fertile.
Conclusion
Challenges against hybridism need to be founded on fact and reality,
not on a mythical concept of inviolate species, but on the reality of nature's
harshness and cruel selection methods, our historical precedent with varying
bird species, and the realization that change and adaptation are the only
sure thing in life. How many animal species have been lost in our
history, and how many have been replaced or displaced by others?
How many of those displacements and replacements were a result of hybridization?
Perhaps hybridization is not so bad, after all.