The How to
(An aside and concern)
What is a Variety
A variety is, quite simply, a family or group of birds that has been created through diligent, selective breeding. A family is not developed in two or three years, but often over 5 to 10 or more generations, depending on the system utilized by the breeder and the trait (s) sought. A line, breed or strain of birds is usually markedly different in one particular feature (sometimes more). That feature is emphasized through additive selection, until such time as the offspring produced appear as photocopies of the parental phenotype.
There is no doubt what-so-ever that breeders, and people in general, tend to base their likes, dislikes on certain colors and forms (phenotypes). Hobby breeders focus on the brilliant or eye-catching colors of parrots, often to the exclusion of all else. Consequently, new color mutations are often in high demand. Varieties are another matter entirely. These are not birds that occur through the chance pairing of an otherwise healthy and normal couple, but through a "concept" bird, formulated within the breeder's imagination. The breeder usually begins with a bird that is enhanced in one area or another (a brighter color, a different color or a color exhibiting increased depth and dimension). However, a breeder may ignore color entirely and decide to pursue a physical alteration that he or she feels would improve the species' overall conformation and show value. Physically altered varieties are possible, but there is a greater requirement for a sport to assert itself, where a number of pure bred lines do not exist to generate an F1 or the broader phenotypic ranges associated with the F2.
The breeder who wants a real challenge may work towards "developing" a larger or smaller skeletal frame; select for eye ring enhancement in roseicollis; generate a small bird with perfect form and dark, intense coloring or perhaps utilize a sport with unusual feathering, crest or top knot or even fully feathered feet. The choices are endless, but many varietal types may harbor hidden genetic implications, in the form of sterility, reduced vitality, or other well known symptoms. The observant breeder should be aware of the potential problems with certain physical manifestations, so as to not knowingly proliferate a disease or medical aberration.
Selecting for Color
The creation of a color variety is a very rewarding experience. The breeder essentially molds a bird until it, and its progeny, are visually distinct from any bird in the "normal" population. Upon seeing the bird for the first time in the flesh, a knowledgeable person is able to state, unequivocally, that the bird is a variety selected and bred by Mr. or Ms. X. This is the true mark of success for the variant breeder: the rapid recognition of a bird, which is sometimes more distinctive than many sub-species within a species.
Selecting for color improvement is sometimes analogous to the entry of color on a juvenile's forehead or mask, where the color emerges slowly through a freckle or measle-like pattern, before filling in to reveal the deep red coloration, often associated with lovebirds. The selection process is highly dependent on the original expression of the color sought, and the variance in pattern from the norm. As birds are selected and mated, color is improved or enhanced, generation by generation, until the final color, intensity and distribution match the desired conceptual feature or attribute. Sometimes improvements may be quite rapid, depending on the choices made and stock availability.. However, more often than not, selection is slow and laborious. A varietal development does not necessitate the same level of culling as a hybrid or transmutation, as the selected birds exist within a defined species and are changing due to selective pressure on an existing pattern.
One point to be made here is that the effort needed to generate a variety appears to be inversely proportional to the homogeneity of the stock. This means that as the homozygous loci increase in a certain line of select birds, the effort required to generate an improvement is lower due to the number of existing paired genes. This, in theory, might reduce interference in improving specific traits, but that is not a sure bet. There are, in essence, fewer genes that might interfere with a selective focus on a single trait development: form, size, fertility, comportment and color is already nearing or has peaked at a certain plateau, even before the color option or enhancement was attempted.
In heterogeneic stock, however, the the number of unpaired genes complicates the task immensely, and if a breeder is unwilling to undertake the necessary effort or implement inbreeding or linebreeding, the chances of ever attaining a passing, let alone a lasting alteration, are diminishingly small.
Just to be clear, a person who breeds a particular color mutant for many years, and outcrosses to introduce color or improve vision in a mutation like the Lutino, is not generating a variety. If the Lutino is managed for brilliance in color, focusing on white flights and rump, with no sheen, and overall dark yellow feathering, the breeder is merely perpetuating the standard. The fact that an outcross was introduced into the line, could lead towards atavism rather than gain, particularly if the pedigree of the outcross is unknown.
Breeders will know that when seeking to initiate a new variety the best method, I cannot used the word approved, is to cross two select (homogeneous) lines to produce F1s and then cross the F2s to generate a broad spectrum of potential phenotypes. I think it is well known that select lines that have been managed correctly rarely run into problems with infertility or other issues associated with random inbreeding. This, however, may be a fortuitous result of certain lines or families harboring fewer troublesome recessives in their genome, rather than breeder skill. As well, several lines usually disappear before the final lines are selected. The successful lines or families have a tendency to generate greater heterosis in their hybrid offspring. It is interesting to note that despite all of the negativism that exists towards inbreeding and linebreeding, the overwhelming fear seems to be focussed on inbreeding depression ( a term I have used on some of the pages in this site). In reality, homozygous lines do exceedingly well and can generate significant strides or "improvement" (always dependent on what one considers to be an improvement !!) in a relatively short time.
Here is an interesting question for the geneticists among us.
Using a breeding methodology, and applying a mathematical
formulae to a
caged population's development, is it possible to have heterosis
and inbreeding depression occurring in a single, distinct population, over time,
while the mean oscillates, but improves generation over generation.
If so, how ? If not, why not ?
How do they do that ?
The breeder may arrive at a decision to "develop" a variety, following general observations of his or her birds over a period of years or may suddenly happen upon a bird that has a much larger area of faded or muted color surrounding a principle feature than is usual or perhaps exhibits an outstanding highlight feature that cold be improved upon (eye-ring, tail or flights). This bird then, becomes the central focus for defining a new color and / or form ("variety").
The breeder reviews the bird's pedigree (records / history) to confirm its lineage. If parental birds have been in the aviary for many years without throwing a similar, and equally distracting offspring, the chances of them producing another one are relatively small. Depending on the trait exhibited by the bird, the breeder may want to determine the best cross to bring out or enhance the additive factors that enabled the alteration in the first place. In the majority of cases the genes are either recessive or modifiers. Some breeders would mate the bird back to one of the parent birds: the reasoning being that something occurred within the parent bird's germ cells or autosomal structures that combined or complimented one another well enough to generate a new "factor". By backcrossing to the parental line, the breeder should be able to optimize the potential for the varietal bird's genotype to merge with the parental genotype and thus produce 1/4 visual offspring.
Another approach may be to select a bird that is outstanding in the feature(s) that is most wanting in the "sport" or seminal variant. If the mask is broad and deep, with clearly defined edges, but lacks the intensity and depth of feather necessary to make it standout, the breeder can select from a closely related line of birds that has the same color in the brightest and most intense hue. In this way, the breeder seeks the additive properties of the brighter color and intensity from another line, and a way to introduce them into a merged variant line. Selection of birds is performed to balance phenotypes.
Some may question the principles and concept of additive genes, but I think that there are a number of alleles that carry the possibility for modifying color and other attributes, throughout a very wide spectrum: the majority of which we have not seen or perhaps not recognized yet. Furthermore, that the common colors that we see replicated repeatedly in our birds, through the application of mendelian genetics, are in fact those colors that compose the median or mean color for a specific color mutation. However, the variability in color that we, as breeders, often see in our stock, sometimes makes us look again and wonder what we have in our aviaries. The color spectrum may be pretty well finite to us, but the way it expresses itself through minor modifications in melanin, the cloudy layer or feather shaft diameter, oil from a preen gland, or feather orientation, can all impact a bird's final color as perceived by the breeder. In many cases, we do not have the population necessary to observe the extreme ends of the spectrum, except by chance: much like mutations. One may liken this explanation or thought to the binomial curve and the two tails on either end being the extremes of variation in the color spectrum, with the majority of known colors and modifications covering the brunt of the area under the primary distribution curve, and the unknowns lying unseen and unobserved in the "tails".
Bird Color (An aside and concern)
I think we need to be clear on what we are addressing when we talk about color in birds, before going any further. We know our birds will reproduce their particular color mutation, in their offspring, based on dominant or recessive genes. However, I think there are also those who know that color, hue and intensity can vary widely between progeny and parents.
many people do not believe in additive gene genetics and the ability to enhance color through breeding and selection. However, I believe it to be possible, and it is applied because the potential for additive or summative improvement in color makes all the difference between a good and excellent bird. Just as Cinnamon, albinism and lutinism are "modifiers" of colors, so too are various structural elements and biophysical structures (macro and micro-scopic). The problems arise when multiple color mutation crosses are made (inclusive of various forms of color and structural modifiers) and the phenotype is difficult to define, let alone try and duplicate. Whether people want to admit it or not, they are usually crossing color mutations with the hope of deriving a new mutation. Unfortunately, a blending or merger of existing mutant colors will not generate a mutation or variant. It is simply a combination color, and the more color combinations that are merged in a bird, the closer it reverts to the wild color. Remember that every color mutation we see has been painstakingly tweaked out of the wild color and steadily "improved". Recombining color mutation genes simply moves the bird back toward the wild type color and re-establishes known color dominance, penetrance and expression.
A concern I have is associated with the approach to color today, and the attempts to name or classify birds and mutations that we see today. Realistically, we may expect to see many more mutations before we depart this plane. Some groups are working hard to upgrade and improve the understanding of color mutations and inheritance in lovebirds. Unfortunately, we seem to be experiencing another evolutionary interpretation of how birds should be classed and defined. The insurmountable task of attempting to define bird phenotypes must surely be undermined by the realization that spectral analysis for color, penetrance and expressivity literally encompasses the color spectrum. As we look to the naming systems being proposed, we see the recognition of older terms such as Olive and dark green, which then merge into more recent terminology such as grey-green; sea-green; apple-green; blue-green; dilute~; parblue; parblue1; parblue~.
In order to address the magnitude of potential future colors, it will be necessary to use more and more general terminology and concepts until they no longer have any distinctive, let alone descriptive value. Undoubtedly, we will run into just about every imaginable combination over time: some of which will be exhibition material and many that may have no color or exhibition value at all.
Is it time for bird societies to begin clear and specific education on mutational aspects and clearly define what does and does not fit into exhibition expectations or categories ... How might this be effected?
I understand how difficult it is to acquire color photos or a semblance of easily interpreted color, but couldn't specific mutations be photographed in "standard" light conditions to reveal exactly what visual color is required for each mutation in order for a bird to be shown and receive credit (points) in specific categories. Why make up new names if we have precise definitions and visual understanding of exhibition expectations ? We know that we can and will get birds of every shade, to the left and right of the "Standard", but the focus will be on attaining the standard. If a mutation with esthetic value appears, then name it, define it, photograph it and upload it, so breeders can download it and use it as a guide ( again, standard lighting conditions and boxes ...as in the exhibition hall). Computers, today, are better than they have ever been, with regard to color presentation and capture, and I dare say that the color on the screens is also well calibrated and fairly reliable. If the requisite pictures of "standardized" mutations can be taken for primary computer platforms, and then studied / critiqued or assessed by judges. Surely we can make these available as downloads, and consequently improve understanding and knowledge?.
Color mutation naming is an interesting pursuit and technical challenge, but is it an "evolutionary" dead end when one concieves a full spectrum of "possible" colors that are likely to be generated over time. Please focus on perfecting and distributing, as-true-to type color photographs of the specific color mutations, as they appear, instead of trying to label every bird's color, variant, shade and hue with terminology that is disingenuous, innocuous, non-descriptive, or worse, explained through % density or suffusion.
"Precision provides clarity and understanding, not misunderstanding and confusion"
"A Picture is worth a thousand words"
Selecting for Color cont...
Having identified the bird (s) which expresses the greatest intensity of color, that you could mate to the "variant" (let us assume it is a cock), the breeder must look at all of the features of the hens that have been selected and compare their form to that of the variant or "foundation cock". If the cock is deficient in some area, as he may very well be, ensure that selected hens exhibit that feature in excelsis. All other factors can be adjudicated as if you where preparing and evaluating your own stock for show. In this instance, we have one cock and numerous hens. The fortunate and meticulous breeder, will be well aware of his older hens ( 2 / 3 years) productivity, offspring form, parenting skills and whether any hen is prepotent for certain traits.
The breeder places the hens in cages and puts them next to the cock (in a similar cage). The birds are visually assessed at this point, and photographs of the hens and cock are taken and downloaded to the computer for further review. The breeder's experienced assessment or comparison of the hens and cock can be confirmed or refuted by the camera's use, which can capture the pros and cons for each hen and the cock (this step can not be emphasized enough. Success depends on it). The breeder, having reviewed the camera shots, selects three or four of the best hens between 6 and 12 months of age. As soon as the cock is old enough to mate (6 months onward) the breeder should put him to the selected hens (I do not recommend or encourage the putting together of hens or cocks younger than 12 months of age, if: aviaries are located outside; your birds have a history of egg binding or you have been selecting for skeletal traits that could impact egg laying).
Some of you may not be very comfortable with the breeding approach, given that so many pet breeders are opposed to breeding younger birds, but there are also measurable benefits from breeding young stock. If your hen becomes egg-bound in the warm quarters of a house, or a protected shed, it is likely that she will be problematic for your own breeding program and undoubtedly continue to experience similar problems in the future. Whatever the case, I look at egg-binding as a weakness in the bird, just as no claws, a damaged beak, faulty conformation, long feathers or other traits might be perceived to be. If you have egg problems with the hen, save her or have her vet treated, if necessary, and remove her from the breeding pen. Sell her to the nearest pet store with the admonition that she not be bred. This is all you can do to prevent her from running into problems in the future. Ensure the rest of that line / family and trickle down is sold, you cannot afford egg-binding in your stock. Breeding hens need to be in top condition and as hardy / able as you can find them... they are feisty little birds and are far hardier than we give them credit for.
Mate the cock to the hens as stated earlier, with the objective of spreading the split "genes" among as many hens as possible 4 - 6. I know that some of you will not believe this can be done, but the cocks are frisky things and will usually attend to most females that request a little extra attention. Needless to say, this is very similar to a budgerigar process, and as such there are two approaches:
The male may be a little confused at first, and the hen may be aggressive, so it will be necessary to watch these introductions closely and for some time, being ready to intervene at any moment, as required. Hopefully you have a cock that is fearless and sidles up to the hen very quickly. If he is able to stand up to the hen's bluffs, things will go well. If he is not, or he exhibits fear of the hen (and she is chasing him with an open beak or acting very aggressively,... ) replace the hen with a back-up, as the cock is, at this stage, the vital element in your breeding plan. Sometimes matings will occur without a hitch, while in other matings there are some real challenges.
Please do not attempt this activity if you are a first time breeder or you want to try it for trial sake. Birds can and do get killed if put into volatile or dangerous situations. Although the cock can and will kill, it is unusual, and in the majority of cases it is the hen that kills the male when the introduction does not go off well, he fails to comply with her demands or for some inexplicable reason she just does not take to the cock. The juvenile hen will not be as big a concern as the adult hens. Adult . experienced hens, if receptive, will expect the cock to perform his function. Failure to do this or clumsy activity may lead to a bit of sparring and separate corners for short time. Watch and be mindful as a breeder and step in quickly to prevent any bloodshed. Know your lovebird behavior before attempting anything like this. Remember, lovebirds can be very aggressive.
The opportunity to develop a variety, based on a sport is a rare circumstance and one that needs quick action by the breeder if saving and proliferating the genotype is desired. If multiple hens is an anathema to you, you might try a less or perhaps more objectionable method, such as artificial insemination. Whatever method you choose: natural; multiple or A.I., if you really want to utilize the "sport" and develop your own line, you will need to move quickly. There is nothing that says the bird will not die on you or that some unfavorable circumstance will occur which will dispose of the genotype for you.
The hens should be in good condition by the time the young are ready to hatch (hens would have had daily interaction with the cock throughout the laying period). If one were to examine the current statistical specifics for hen activity in the wild (species other than lovebirds), they would realize that a hen can exceed 1,000 trips a day to the nest box, to feed its young. Lovebirds, in good health, in confined quarters and with ready access to seed and water should not run down like they might in the wild, if subject to one or two single parent nests in cages. If you are concerned by this approach or the potential for chick mortality, the eggs or chicks can be fostered out to feeders. This will enable the caged hens to recover for a second round. In the aviary situation, the cock should be left to assist with feeding where best he can.
As the progeny develops, assess the chicks for the desired characteristic, conformation and size. If the line was already inbred, these young birds should not differ markedly from each other, although some may express a weakness or fault present in the male. At three to four weeks, you can assess the nestling wing feathers (not flights), size, head and forehead color. At approximately six months, the birds should be through the molt and their color should be more striking. Look over the young stock that was not initially culled for faults. Offspring will reveal a spectrum of color forms, that may or may not show marked improvement in the direction desired. The hens should be back on the nest, raising their second and final, clutch with the cock. Assess each hen's egg production with the foundation cock and determine percent fertility. Compare these results with her previous clutches and fertility if possible. It is also valuable to know and record the number of fledglings versus fertile eggs from each hen.
Put the best juvenile daughters, split for the trait sought, back to the foundation cock: the breeder may also want to put together one or two brother / sister combinations... if these birds exhibit superior qualities. Check the juvenile hens to make sure that they too excel where the cock exhibits faults and vice versa (as best one is able)
Mating brother and sister will be helpful in confirming inheritance and allow for further progeny evaluation (but, not if the line the birds are from has attained an inbreeding depression plateau [6, 8 or 10 years], which translates into low heredibility values due to leveling off of homozygous genes [homogeneous population]).
Repeat introduction and mating steps for the foundation cock to the juvenile hens as previously outlined.
Offspring, resulting from the matings of juvenile hens to the foundation cock, should exhibit the trait being sought. Evaluate each juvenile hen's egg production and calculate fertility to identify any drop or reduction in fertility levels (compare to line average). the breeder may also want to record the number of fledglings from each juvenile hen's clutch. Some offspring may exhibit significant increase in color and patch size, some may reveal zero or minimal variation. Let these offspring pass through the usual developmental growth stages, and when they are ready, proceed to cross them with the foundation cock. Dispose of hens that laid too few eggs or exhibited low fertility (4-6 egg target clutch) in the 1st round. Do not mate the cock to juvenile hens from a low fertility hen / clutch.
In the interim, the breeder can look at the results of brother / sister matings, and perform similar evaluations on juvenile hens and cocks. The offspring from these pairs are absolutely acceptable to use in the breeder's breeding program (if the parents pass progeny and fertility analysis), and should be mediocre to very good offspring, depending on the quality of the birds paired (should have been outstanding).
From the offspring of the juvenile hens by foundation cock matings, select those offspring that exemplify the trait sought, and when they attain reproductive age, mate those birds. Adhere to the: excellence balances fault methodology. The eventual result of these crosses should be birds that clearly express a significant improvement and penetrance of the desired trait, although the breeder will still has some work to do in "tuning" up the final appearance, fixing the intensity and sharpening / clarifying color definition.
From the offspring of the brother / sister cross, identify those birds with the large, intense patches of color (brother /sister), and put them together at the next cross. The focus then shifts towards increasing intensity and / or definition around color edging. The breeder may want to consider introducing the foundation cock, if for some reason this generation of stock seems smaller than him, but it is unlikely that he will be able to add much at this point, unless he is prepotent, and even that is passed on to his offspring at this moment in time. The breeder will have to weigh whether his further inclusion in the development of this new "variety" is worthwhile, as the foundation cock's muted color may modify the intense color being produced by later generation offspring.
Remember the second (and last) round of chicks produced by the original
hens and the foundation cock ? Cross the brighter birds with larger
patches from this second clutch, with some of the offspring from the final
brother/sister matings and continue to work to develop size and color definition
within the new variety. From this point onwards the breeder can move to
the easier, but similarly demanding job of continuing to evaluate stock
and matings, by combining best to best in each round, while paying attention
to fertility and form. Run a normal exhibition show and set your
birds up left to right as you make your selections. Ignore relatedness
ar this stage and focus on those birds that you think will improve the
overall conformation and look of the bird, while addressing fault corrections
and ensuring birds remain viable and healthy.
Hereditability will increase when the "sport" or "variant" is introduced back into a fairly homogeneous population, but within four or five generations has plateaued again, as the genes in the new "variety" move from heterozygous to homozygous in the new strain. So once again, we are talking about the use of additive genetics in improving the intensity and expression (penetrance) of color in a new variety, that is distinctive.
A few items worth mentioning for the breeder: