Abstract
Hybridization is an issue which has increasingly come under scrutiny. As a practice it is controversial, emotional, and frequently not well understood. There is a misconception that it is comparatively harmless, when, in fact, quite the opposite is true. There is a need to be better informed on what hybridization is, what it does, and its affect, not only upon the resource, but aviculture itself.
Hybridization occurs when the male of one species is bred with the female of a different species. Progeny produced by mixed pairings are hybrids. It is noteworthy that the dictionary definition of the term hybrid is mongrel.
Most hybridization occurs with macaws. Because of their distinctive patterns and brilliant colors, hybridizing can produce unusual affects. Such affects notwithstanding, hybrids do not equal the beauty of pure species. For man to presume to improve upon that which nature has already accomplished is ridiculous. In view of the potential for disaster it is also irresponsible.
Proponents justify the practice under the rationale that included with ownership is a right to utilize the resource as they see fit. Opponents disagree. While it is conceded that ownership grants rights, they believe that included with those rights are responsibilities, one of which is utilization that is in the best interest of the resource. Hybridization is not considered as being in that interest.
Because of various factors, among them being habitat loss and illegal capture for the pet trade, the survivability of macaws is in jeopardy. Scientific professionals are concerned that several species will be exterminated within the foreseeable future. Should that occur, their survivability will depend upon their being preserved in captivity. For that to happen it will be necessary to establish comprehensive breeding programs which will ensure captive self sustaining populations. Although macaws are bred in captivity with some regularity, sufficient breeding programs, which could ensure their survival, do not yet exist.
Some of the basic principles of genetics are helpful in demonstrating why hybridization is wrong. The genetic composition of every species is unique unto itself - different from all others. For a species to survive it is necessary that its genetic integrity remain pure. Once hybrid genes are allowed entry into the gene pool, the purity of the species is compromised. Hybrid genes cannot be removed, but essentially exist forever. The potentiality for hybridization to compromise genetic purity is a matter which cannot be taken lightly. The sobering fact is that hybridization can be correctly defined as death to species!
Individuals who hybridize frequently justify themselves under the rationale that birds produced are intended not for breeding but as pets. Once produced there is no assurance that hybrids will not be utilized for breeding, and frequently they are.
Unlike humans, animals lack the ability to reason. They rely on instincts to guide their activities. Instincts are acquired from genetic material inherited from parents. A newly hatched waterfowl, for example, as a result of genetic inheritance, recognizes water as an appropriate environment. Although all macaws are similar to one another, each species has its own genetic composition which is different from all others. Different species may choose slightly different habitats, feeding practices vary, as do breeding instincts and so on - again, each species being unique unto itself. When hybridization occurs, the combination of two different sets of genes compromises the ability to react correctly to the environement. A mixed set of genetic signals results in confusion which impairs hybrids' capability for survival.
Included in conservation goals are plans to reintroduce captive reared macaws into areas where there is need to rebuild or reinforce depleted populations. Some programs have already been initiated. Only birds which are genetically pure are suitable for restocking. Individuals which are genetically imperfect would have a low potential for survivability and would be valueless for such purposes. In consideration of this, the need to control hybridization is obvious.
Hybridization occurs for different reasons. Often it is unintentional, occurring accidentally when birds of different sex and species are housed together. More frequently, however, it is the result of intentional planning in which birds are paired for the specific purpose of producing hybrids. The progeny is then often represented as something rare and unusual, frequently to ill informed buyers, and often at unjustifiably inflated prices. Such activities are ethically questionable.
Another misuse occurs when birds are used for experimentation. Efforts have been made to produce an all yellow and an all red macaw. There is no justification for attempting to manufacture new macaws. They already exist in a magnificent variety. They are rare birds, not toys. Our only consideration should be not to endeavor to improve them but to preserve them as they are. An unfortunate aspect of hybridization is the wasted breeding potential. Far better that rare birds be utilized in the production of pure offspring, with the capability to perpetuate the species, than in creating hybrids which are valueless for species preservation.
There are powerful forces opposed to keeping wildlife in captivity. They work continually to have legislation enacted to restrict or deny the right to own birds. Irresponsible avicultural activity, such as compromising the genetic purity of rare birds, contributes immeasurably to their cause. Because of such activities, the scientific community views aviculture with low esteem. Avicultural practices also attract the attention of outside interests. The general public is increasingly concerned for the welfare of birds. To presume hybridization will be allowed to continue without gaining attention is unrealistic. It is also unrealistic for individuals who are not breeders but bird owners to presume they will be unaffected. If restrictive legislation is enacted it will not be directed specifically toward those who hybridize, but will involve everyone.
Imagine a future in which macaws existed only as a hodgepodge of mixtures. Impossible? Don't count on it! Hybridization is in no one's interest - least of all the birds. It is irresponsible, it accomplishes nothing worthwhile, and must not be allowed to destroy our right to own birds. The merits of hybridization, or more appropriately the lack thereof, could be discussed interminably. However, a summation can be made in a very few words . . . individuals who hybridize jeopardize the survival of rare birds. Hybridization is a loser! Are we, or are we not, willing for it to continue?