Fallows – Part 3: The AIDA strategy

The AIDA strategy:

  1. Amplification of the rare recessive trait. Pair your Fallows with the best normals from your exhibition stud.
  2. Introduction of desired genes (from exhibition birds) to birds with the rare trait (in split form). From these pairings no visual Fallows will be bred and you will not know whether your birds are carriers of the Fallow gene or not. These pairings are the key to your success later one.
  3. Determination of the carrier status of your birds. All birds from the above mentioned pairings have to be paired with Fallows. The resulting visual Fallows will be used for control pairings. Only the split Fallows that have now been confirmed are used in your future breeding program.
  4. Analyze your progress. Compare the visual quality of your split birds with the quality of your best birds. If you are happy with the small improvements repeat steps 2.) to 4.).

With this method the progress will be slow within the first years but sensational afterwards. You will need a lot of visual Fallows for control pairings but do not be tempted to pair the split Fallows together before you are happy with the visual quality of your splits. Do not expect progress by pairing Fallows to split Fallows. The most valuable birds for your breeding program are the birds that are split for Fallow.

The key to success will be the fertility of your birds as you expect to perform only one round for your control pairings and you need large numbers of offspring to select the birds with the desired characteristics.

Are cocks or hens more important in your Fallow breeding program?

SM: The quality of the cocks is the most important part in a pairing. Good cocks can transmit their features to cocks and hens as well. Good cocks can be mated for several years with several hens each year resulting in many half-sisters and half-brothers that will be the basis for building a winning line or even a winning stud. I prefer to buy good cocks as outcrosses and I aim to breed tipy hens myself. My preference for good cocks, if possible buff cocks with broad shoulders, holds true for all budgerigar varieties including Fallows.

FM: If we are biased then we are not only slightly biased in favour of the hens. Good hens or even better a handful of good sisters of real quality are the motor for a successful breeding program. We started to breed Fallows with two single birds only. The offspring of the cock were used to breed more Fallows for experimental and control pairings. In these cases we bred with cocks and hens. The offspring of the hen were used differently. To upgrade the Fallows with the above mentioned AIDA strategy we only used hens from this mating. There are plenty of reasons for this. The foundation hen did not stop laying eggs before the first chick was hatched. We wanted to keep and propagate this exceptional peculiarity in our stud. The only way to assess the inheritance of this feature is by using female offspring. Unfortunately this trait was never ever found in the offspring. The minimal number of chicks fledged per clutch was 6. We knew that the cock that was mated to the Fallow hen was very fertile, because he was testmated before, but we also hoped that this hen could store semen for a prolonged time as is claimed in the literature (?). Furthermore, it is known that specific genetic information is only carried by the hen. A part of this information is only found on the Y chromosome of the female bird. In addition very important information that is necessary for the generation of metabolic energy in the mitochondria of every cell, is passed to the offspring via the hen only. Mitochondria are very small organelles that represent the power plants of cells and we speculate that they are partially accountable for the temperament of the birds too. The information for the functioning of these power plants is also carried in the motile germ cells of the males but is lost during the fertilization of the egg. Last but not least we intended to breed preferentially Opaline Fallows. Only a part of the hens carried the Opaline factor. In fact we started the upgrading of our Fallows with 5 Opaline hens that were split Fallow. All these hens were daughters of our foundation hen.

How do you improve feathers in your Fallows?

SM: Feathering, especially directional feathering, is difficult to improve. I divide my budgerigars into three standard categories: yellow, intermediate and buff and I aim to have in all pairings a buff partner with coarse feathers. My preferred picks are normally buff cocks as buff hens tend to be poor breeders. Following these principles my Fallows are paired to buff partners in most cases and consequently feathers have been improved over the years.

FM: In our opinion the yellow-intermediate-buff theory is a very attractive concept that was adopted too quickly in the fancy. The broad phenotypical classification of feathers into these three categories is an oversimplification and in the final consequence meaningless. To add to the confusion many fanciers realized this and added even more categories such as medium buff and super buff. Feathers are very complex structures and length, shape, width, thickness, down, structure of barbs and shafts all contribute to the final appearance of the bird. The inheritance of feather structures is in our eyes the least understood aspect of breeding show budgerigars. Beside this the bone structure, the skeletal dimensions and the muscularity are so important for the first and the lasting impression. Of course the length of feathers is a prerequisite to have a deep mask, and width is important in order to have good spots, but we are not part of those feather specialists who can talk about feathers and the heredity of feathers for hours. Feather analysis is not important in our breeding program. Our Fallows have feathers and that’s it.

Fallows do have very silky feathers compared to feathers of Normal budgerigars. We have shown that Fallows can be recognized by handling alone. Our experiment was very simple: We presented to a friend several times a pair of Fallow and Normal nestfeathers. His task was to determine the Fallow. In all 50 (fifty) trials he succeeded. Our friend is blind. He failed to find the Cinnamons in a similar experiment.

What is your opinion about feather dusters?

SM: I have had enough feather dusters to know that there is a potential for quality in my lines. Breeding of feather dusters is a sign that you are achieving the maximum level of quality for your budgerigars. If that level is still not what you want then you have to introduce outcrosses to your stock that should bring you to the next level. So far my Fallows are not good enough to produce feather dusters.

FM: The production of feather duster monsters is detrimental to all breeding efforts. We believe that the occurrence of these nonviable mooncalfs is a sign that your lines have been bred into a dead end. When you go on to breed with the parents or the siblings of these feather dusters then you have achieved the maximal level of incompetence and you have probably lost all common sense.

How do you go about judging Fallow budgerigars?

SM: There are basic principles independent of which variety is being exhibited and judged. A good budgerigar has to be as close as possible to the standard of perfection. A good head with no flecking, broad shoulders, deep masks together with color and markings are very important. Today the biggest Fallows are winning independent of other considerations. This will remain acceptable until such time as the gap between first class budgerigars and the Fallows is filled. Colour considerations are not important at this stage. I am not a judge myself but I have no problems entering my birds under a judge who does not keep Fallows. One day you will win and one day you will lose.

FM: We are happy to breed good Fallows and we breed and exhibit for fun, not to please judges. We enter the birds under all judges. Exhibition is all about promotion. We promote the varieties that interest us and we promote ourselves. We never overlook the fact that exhibition is all about blowing trumpets but this is very human and an allegory of human life itself. However, the most important aspects in breeding exhibition budgerigars are the social aspects. There are some terrific blocks out there and it is a pleasure to share such a wonderful hobby with them. We have had a lot of success with our Fallows so far. Our birds won Best in Show and Best Opposite Sex in Show at the by far biggest One Bird Show of the world (2 entries). The Best in Show was an Australian Pied double factor Goldenface Fallow Cobalt hen and Best Opposite Sex in Show was a double factor Spangle Darkgreen Opaline Fallow. Our birds also won several times the Worst in Show award as they were so far behind in type and size. Fortunately all the birds in front were disqualified as our society also included a doping control that consisted of a very simple test. All the birds in the final lineup at the show had to prove that they were capable of flying a distance of 10 feet. It was a disaster if not to say a tragedy that we did not expect. All the birds (chicken) failed with one exception: Our CC winning Fallow budgerigar. Trumpeting is over now. We suggest that similar doping tests should likewise be performed at all the major shows, especially the shows under the patronage of the BS, otherwise the abbreviation CCC could be misinterpreted as Chicken Challenge Certificate.

Proof of the pudding?

The journey to best in show is more entertaining when one has an inkling of how to do it. Please convince me that the AIDA strategy is working as the proof of the breeding is the exhibiting not the trumpeting.

FM: I perfectly agree. As mentioned above we started breeding Fallows with two pet shop budgerigars. This is the perfect situation to assess our AIDA concept as it is difficult to imagine more lamentable birds to start with. Today we believe that we are in the lucky position, for the first time, of being able to directly compare the AIDA strategy with the standard method suggested by Mike Scaly.

As mentioned before the first generation splits with “50% exhibition blood” were of calamitous quality. The second generation splits “75% exhibition blood” that have been bred from these birds (mating with exhibition stock and mandatory testmating) are clearly ahead of the Fallows that have been bred, by mating of the first generation splits with Fallows (=> resulting in birds with “25% exhibition blood”), as far as exhibition points are concerned (head, spots, type). These “75%” splits are however still miles away from good exhibition stock. Interestingly we found that within these second generation birds the carriers of the Fallow gene were the most ugly birds of all. Our best six “75% exhibition blood” hens and the three best males did not carry the Fallow gene. We do not know whether this is coincidence or not. This observation may indicate that the Fallow gene is (of course!) still linked to undesirable traits that are not assisting the improvement we are looking for. These linked traits will be separated in future generations by crossing over. A very strict selection at this point is not yet appropriate. We bred our third generation splits (“88% exhibition blood”) with these second-rate birds. This is a typical situation of a “pedigree only” based selection that does not consider the phenotype of the birds: A dilemma that we face again during the breeding of the fourth generation. Therefore we use for the first time split Fallow cocks in the process of upgrading. This will increase the number of birds that can compete for the breeding pen and give some hints about the role of the X chromosome to influence showtype.

To demonstrate the usefulness of the AIDA strategy to improve size we determined the size of adult  second generation birds (n=9, hens only), adult third generation birds (10 hens, 7 cocks), adult fourth generation birds (3 hens, 4 cocks), adult Fallows bred from first generation splits (n=8) and our blue exhibition family (n=17).


The increase of the mean size in the first generation splits is not significant (0.3cm). However, the increase of the mean size between the Fallows and the second generation splits (hens only) is 1.1cm already. Adult hens from the third generation birds measure on an average 22.4cm, the corresponding cocks 22.8cm. The fourth generation birds measure on average 23.1 cm. The hens 22.3cm and the cocks 23.8cm. A very interesting difference between the sexes we didn’t expect.

The observed increase is indicating that we have been moving in the right direction despite the low number of birds we obtained in the fourth generation.

On the graph below we correlated the percentage of “showtype” genes and  the size of the birds. It is obvious that improvement in size can be obtained by the addition of “showtype” genes. It is probably not feasible to achieve a similar effect by selection alone.



The analysis of the size distribution in the third and fourth generation splits revealed interesting points.



The variability is high: The difference between the mouse (21.5cm) and the giraffe (24.5cm) is 3cm. Hens are smaller than cocks. Few individuals have the required size of 24 cm. All the other features have to be improved. Another five years plan to think about.

Psychologically it is very difficult to breed split Fallows with Normals for several years in a row because a Fallow breeder would like to breed Fallows. To motivate myself I looked several times a week at the dot found in the right corner of the graph above. The BIG DOT in the right corner was split Fallow and a double factor Australian Pied Light green. Test mating can be a big thrill. Is this pudding sweet enough?

How do you test your Fallow maybe splits?

By breeding with Fallows indeed. Our testmating procedure is very simple. In a testmating with a Fallow at least three chicks have to be reared and if no Fallows appear then we consider the birds not to be split Fallow. The probability that we miss a carrier of the Fallow gene is reduced to 12% (1 out of 8) with a minimal number of three chicks. If four chicks are bred the probability is down to 6%. The results of a given testmating are already visible immediately after hatching (red eyes!) and the confirmed split Fallow birds can be prepared for the mating with exhibition stock very smoothly without the necessity to rear full clutches of substandard Fallows.

Are split Fallows that have been ‘washed’ through normals more capable of producing quality?

FM: Yes, if the normals have been of exhibition quality. Why? Because in general the Fallows lack most of the exhibition qualities and therefore lack also the genes that carry the information for these qualities. All the missing genetic information required “to construct” an exhibition bird have to be introduced from outside into our Fallows.

A simplified model:

Imagine that only 10 independent recessive genes are required to define a show bird. A perfect show bird has 10 pairs of these recessive genes that are missing in the Fallows. In the first generation all the offspring will be split Fallow. All these birds carry exactly 10 single copies of the recessive genes in split form. The birds will not be improved at all because not a single one of these recessive genes is in double form (to be effective). If you pair these split Fallows together some of the offspring will show small improvements compared to the Fallows and the split Fallows. This is not a surprise as the recessive genes found in the mother and in the father will randomly combine, resulting in Fallows that may carry two copies of one or more of these 10 recessive genes. But one gene in double form is not enough: In this simple model you need ten! These small improvements mentioned above will be minimal if you relate it with your ambitions. Don’t be fooled by the small visible progresses. Genetically the “improved” bird from these matings is not capable of producing good offspring. Most of the “showtype” genes are still missing. However, if you pair split Fallows (with 10 recessive genes each) from the first generation again to exhibition birds (with a double dose of the recessive genes) then it is obvious that the probability that two corresponding recessive genes will combine in a chick is increased. The required genes (all of them!) are found on both sides of this mating. In contrast, by breeding these splits to Fallows you diminish the small amount of “good genes” you introduced in the parental mating. Mission impossible.

In the case of split Fallows from the first generation, the average number of the required recessive genes that will be distributed to individual germ cells (eggs or spermatozoides) during meiosis is 5 (out of 10) as the total amount of genes is divided by two. The exact distribution of these independent genes is not predictable. In some germ cells you may have 3, 4, 5, 6 or even 7 out of these 10 genes. If you select (by chance) the offspring that received 7 genes from the split Fallow parent (the probability is 12%) you will be surprised by the quality of the offspring. However, the probability is also 12% that only 3 out of 10 recessive genes are found in an individual germ cell. As you have no tools to determine the carrier status of the maybe splits, you are advised to test all your maybe splits not only for the presence of the Fallow gene, but also for the presence of required “show type” genes. This selection can be done visually. In contrast, the carrier status of your split Fallow for “show type” genes cannot be assessed if the birds are crossed back to Fallows or split Fallows.

At this stage you have to face minor disadvantages. You will not breed one hundred Fallows in the first season and you will not know whether the chicks produced are split Fallow or not. But most importantly, you will see for the first time the hidden genetic quality of your split Fallows in the quality distribution of their chicks (BIG-DOT effect). This is theoretically and practically the only way forward with most of the recessive varieties. Please try to estimate the probabilities mentioned above. By using your common sense you will never look back. Start to pair your split Fallows together when you are happy (happppy with four p’s) with the quality (compared to your best exhibition birds). Erstwhile, the Fallows you produce will be Fallows bred from testmatings “only”. The quality of these Fallows will improve slowly with the quality of your splits too. However, this is not quick enough. Go for the splits and mate the splits with your best exhibition birds. This strategy only works when you have enough fertile and fit Fallows for testmating. The time you invest for testmating is not lost. The time to invest for testmating will be six weeks maximally for males and three months for hens. Results can be analyzed immediately after hatching. The speed of your progress will be dramatically increased later on.

This “10 genes only” model is an oversimplification, and it may be anticipated that several hundred of recessive and also dominant genes, that are in several cases also linked, may be responsible for the differences in the type of budgerigars. (In dogs it is estimated that roughly 500 genes are responsible for the characteristic differences between dog breeds.) This model is, however, good enough to illustrate the advantages of the AIDA strategy and this model can also explain why it is so important to breed large amounts of chicks from individual pairs to optimize selection.

Are Fallows weaklings and slow developers?

FM: Exhibition budgerigars tend to mature slowly compared to pet type birds. This is not surprising. Today our Fallows do not show delayed maturity. They develop in parallel to their normal siblings. Fallow hens (and also their normal sisters) have nut-brown ceres at six months already. At this age most of them are in breeding condition. Our Fallows seem to develop perfectly normally from the first day on.

However, if we speculate that one of the three confirmed Fallow genes is homologous to the pink-eyed dilution locus p of the mouse [see reference 4], then it is not surprising that certain strains of Fallows show dramatically increased chick mortality as described in the literature. For comparison: In mice more then thirty different mutations of the pink-eyed locus are known. Most of them have problems associated with reproduction (sterility in males, juvenile lethality mild to severe). Similar dramatic observations have been made in mice with mutations of the tyrosinase gene Tyr, another candidate for a Fallow locus within others [reference 5]. Scienific work on red eyes in budgerigars revealed important differences. It was scientifically shown, that the presence of red eyes is not indicating that budgerigars have problems associated with light. They still produce by far enough melanin for protection [reference 7] and they, and this is a very important second point,  behave normally.

On the graph below we plotted the fitness parameters clutch size and number of fletched chicks from 107 pairs that completed 213 rounds. We compared the reproductive success of three different populations. Namely, pairs with one visual Fallow (37 pairs, 59 rounds), pairs with one split Fallow (9 pairs, 22 rounds) and pairs with Normals only (61 pairs, 132 rounds),



The variation in all three groups is very high and the significance of the differences can be discussed. The average clutch size in Normals was 5.4 ± 2.7 eggs and the number of chicks fletched was 1.6 ± 2.1. The corresponding data from pairings withs Fallows are 4.8 ± 2.9 and 1.6 ± 2.4. Split Fallows produced an average of 2.7 ± 3.1 chicks from 6.4 ± 3.1 eggs. It is clear that Fallows and split Fallows perform not worse compared to Normals. Such data are psychologically very important and indicate indeed that these Fallows are in good shape and healthy. The presence of the Fallow gene is not detrimental to the reproductive success.

The question about the number of different Fallow genes and their mechanism of action is still not answered yet. Maybe one day the sequencing of the budgerigar genes that are understood to be involved in color production (e.g. Tyrosinase, pink-eyed locus transporter protein e.o.) will give us the answer. These data from the sequencing could provide the Fallow breeders with a tool to assess the carrier status of maybe splits by DNA fingerprinting without testmating. Science Fiction in the Fallow breeding room?

What is happening when a prepotent Fallow cock is mated to a prepotent Fallow hen?

FM: We expect to notice a sensational explosion and we probably have to rebuild our aviary. So far we could avoid such a catastrophe because we don’t know how these “prepotent” birds (myths) look like.

Can Fallows help to improve other varieties?

FM: Fallow budgerigars are beautiful birds. The exhibition quality is nevertheless still poor. Exhibition budgerigars cannot be improved by using Fallows.

However, Fallows might be useful to solve an enigma that is related to the Yellowface varieties and the Blue allele(s). So far nobody has proven (sorry Mr. Ken Gray) without any doubt that all Yellowfaces (Goldenface, Yellowface mutant 1, Yellowface mutant 2) are multiple alleles of the same Blue locus.

Why should a double factor Yellowface mutant 1 become blue? We prefer the alternative Yellowface model that was first published in the Internet by Peter Bergman of Sydney speculating that the Yellowface mutant 1 birds (Creamfaces) are a composite variety of two different Blue alleles. The Yellowface topic is highly controversial as fanciers of world fame still believe that the Yellowface factor can be carried by birds of the Green series (e.g. the legendary Goldenface Lutinos). Only a few people grasp the “Bergman model” and only a handful think about it. We are currently mating Yellowface mutant 1 budgerigars with Goldenfaces to check whether it is possible to distinguish between the Goldenfaces that are split for the common Blue allele and the Goldenfaces that are split for the “Bergman Blue” allele. These experiments are funny as some of the Goldenfaces are split Danish Pied and some of the Creamfaces are split Clearwing. We are looking forward to find some Yellowface Danish Pied Clearwings popping out, a horror combination for the budgerigar purists. If it is not possible to see differences between these two Goldenface forms on a Normal background it may be possible to see these differences on a Fallow background or on an Albino background. In this case Fallows maybe helpful to introduce a new budgerigar mutation, namely the “Bergman Blue”, and to define a new composite variety, namely the Creamface, formerly called Yellowface mutant 1. Can we observe differences in the color distribution (e.g. yellow spillage) or in the color intensity (e.g. head, wing feathers, tail feathers) in the resulting single factor Goldenfaces? Can we observe differences before and after the molt? Can these differences be attributed to the carrier status of the birds? And so what? Neither the traditional nor the “Bergman” approach can be excluded by the observation of these differences alone. And so what? Based on our observations we suggest that “Goldenface breeders should preferentially breed with the “Bergman Blue” budgerigars, that are identical to the so called “double factor Yellowface mutant 1” budgerigars, to breed nice “yellowfaced single factor Goldenfaces” that do not show yellow spillage”.


Do you breed Cinnamon Fallows?

FM: Yes, by accident. German, English, Australian and Japanese Cinnamon Fallows don’t look like Cinnamons (body color, markings) and they don’t look like Fallows (color gradient, wing color) either. The appearance of Cinnamon Fallows is very similar to “exclusively” colored Inos. Wing markings are very very faint but clearly light brown (cinnamon like). Throat spots are light brown too. Cinnamon Fallows are unique and cannot be confused with Normal Fallows. However, it is not surprising that Cinnamon Fallows have been confused with Lacewings (Cinnamon-Inos). The phenotypes of these color combinations are very similar.

Cinnamon Fallows are very uncommon these days.

Do you breed Spangle Fallows?

FM: Yes, and we have been surprised by the phenotype of the single factor Spangle Fallows. The markings of these birds are very faint and visible only on the wings. Throat spots are light brown and barely visible due to the presence of the Spangle gene. Tailfeathers are completely white or yellow. The Spangle gene is decreasing the body color of the Fallows even more and resulting birds are amazing. Spangle Fallows in combination with two Violet factors will be very smart birds.


Double factor Spangle Fallows are phenotypically similar to Inos.

The Spangle gene is the most probable candidate gene to be linked to one of the Fallow genes. It is regulating a step in the pigmentation process eventually resulting in a decreased melanin deposition in the growing feathers. Functionally related genes are often found very close on the same chromosome. We are prepared to wait ten years to see Spangle English Fallows popping up! I speculate that the breeders of Fallows with white iris rings have a similar “problem” with the Grey factor.

Do you breed Grey Fallows?

FM: We never bred Grey Fallows. I am confident that a relevant part of this question will be answered in Japan in the next future.

Can you extrapolate from your Fallow breeding to the breeding of other recessive varieties?

FM: We do not have any expertise with Inos or with Slates but we are breeding Clearwings and Danish Pieds. Clearwings and Danish Pieds are theoretically more difficult to breed to exhibition standard as the colour distribution and the color contrast play a decisive role alongside the showtype features. The Fallow is a problem variety because nobody is breeding Fallows. Greys and Greygreens are bred preferentially because people believe that the Grey factor is associated with the label “show quality”. Eventually all the best birds will be Grey factor birds because people breed preferentially with these birds. Fallows will become popular again when more exhibition type Fallows will be available for breeding. Once the Fallow is associated with the label “Best in Show quality”.

We advise bringing a showtype “frame” into recessive varieties by using the AIDA philosophy. But we have no idea how to stabilize the colour distribution and how to improve colour contrast. To our knowledge the colour distribution of pieds in most species (cats?) cannot be predicted and never be fixed by selective breeding. We cannot wisecrack on Clearwings as we have never bred an exhibition Clearwing with clear wings so far. By the way we haven’t seen one either.



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