Practice and research
Hans Steiner, bird-fancier and scientist
Motivation: Hans Steiner, a Swiss, visited a bird exposition of "Ornis", a bird society in Zürich. This took place in1922. There he saw at the show the first blue budgerigar belonging to a fancier from Luzern. He was so enthusiastic about this nice blue colour variety that this visit to the exposition determined his whole live. Steiner was very interested in the inheritance of this colour variety of the budgerigar. He supposed that the blue colour was the result of an omission of the yellow pigment in the plumage.
Study: Steiner started to study the research of V. Haecker and his students Spöttel and Kniesche. Haecker was a famous scientist who in 1890 supposed already that the blue colour of bird feathers was caused by a special cell structure of the feather barbs in combination with a black pigment layer under this cells. This was confirmed by research by his student Kniesche in1914. The green colour of feathers arises when a diffuse distributed yellow pigment is present in the cortex, the outer horny layer of the barbs. This idea of Steiner was confirmed by this scientific studies. A blue variation of the light green budgerigar occurs when the yellow pigment is gone totally.
Reading articles in bird magazines: Besides the new blue budgerigar other varieties were developed that time. The yellow budgerigar was one of them. Steiner supposed that both varieties, the blue and the yellow one, should be the result of loss of pigments. If the black pigment is missing the optical action of the cell structure, due to the blue colour, does not take place. The blue structure cannot express himself and a yellow or white feather is the result. If the yellow pigment of the green budgerigar is missing a blue colour appears. Steiner was reading all the reports of breeding results. In one bird magazine Steiner found the message that a white budgerigar was born. The breeder had mated a blue cock with a wildtype hen. The result was a white young. Steiner learned from the breeding reports of this fancier that he used in his stock of blue birds also yellow ones for refreshing the blood. Steiner jumped to the conclusion that by the loss of both pigments, black and yellow a white variety could be bred.
Experimental breeding: When Steiner was in Luzern for a conference of the Swiss Society of Nature research, he took the opportunity to visit the well known breeder of budgerigars, Mr. J.Meyer. He persuaded him to start an experiment to combine the blue and yellow variety. According to Steiner the white budgerigar should come into being in the second generation analogue to the crossing experiments of Mendel. The time that this experiment was known by more breeders they were very sceptical. Most of them never heard of the work of Mendel and they could not imagine that a mix of yellow and blue could give white.
Own experimental research: Steiner was preoccupied with the experimental evidence of his ideas. He decided in 1925 to start the experiment himself. At this moment he did not think about a scientific publication. The experiment would take a lot of work but much time, space and money also. He got help from the director of the Zoölogical Institute of the University of Zürich and financial support of the "Julius Klaus Stiftung". A kind of warehouse was build for this purpose. The walls could be removed in the summer, so the birds could stay in an open aviary. In the winter heating was possible. So breeding was possible during the whole year. Steiners wife, who studied medicine, was his partner in organising, caring and administration. She studied the difficult skill of making cross sections of feathers. Steiner learned that some of the young budgerigars seemed to be ready to breed after five or six month. This could counterfeit the results, so he placed the young after two month in an separate aviary.
Description of colour: He was very careful in keeping up the breeding results. An important task was to make a very precise description of colour of the varieties and name giving. He used to this the colour norm atlas of Ostwald.
Hans Duncker, teacher and bird breeder
Steiner was not the only one who studied the colour inheritance of the budgerigar in the beginning of the last century. There was a teacher in Germany, who was studying this subject. This was Dr. H. Duncker, high school teacher in Bremen. He was an expert on the inheritance of canaries.His varied interests in birds made him a well known expert. With Karl Reich, a canary breeder he studied the canary songs. Ducker became one of the pioniers of the study of inheritance. For years he and Reich were busy trying to develop a red canary by hybridising the canary with the red siskin (Spinus cucullatus) from Venezuela. They did not succeed because the hybrid became copper coloured, not the bright red colour he wanted. Then Duncker changed his interest. With breeding new colour varieties of the budgerigar he was more successful. He was allowed to use one of the biggest avicultures in Germany, belonging to the diplomat C.H.Cremer. Cremer became a bird fancier when he was sixteen years old. He bred tropical birds but also budgerigars and was in the possesion of big aviaries. He was financing some aviaries and a hundred cages for experimental breeding. Duncker was very interested in studying the inheritance of bird mutations. Duncker started a magazine also: "Birds from foreign countries" with the purpose to bridge the gap between scientists and amateur bird fanciers. In popular and scientific magazines he wrote about the use of the laws of Mendel in the breeding of birds. Duncker became also the first chairman of the National bird society of Germany, AZ. So he became an influential man.
Dunckers ideas: His explanation of the colour of the budgerigar was that the colour of the budgerigar is the result of three genetic factors. Genetic changes in this three factors could explain all new colour varieties.
Duncker was distinguising F, O en B factors.
F = Fat (German= fat). Fat drops are the carrier of the yellow pigment. The supposition of the fat carrier factor was derived from his research of the inheritance of white canaries.
This research of Duncker gave way to the understanding of the inheritance of red and yellow pigments. A white colour variety of the canary has no yellow pigment. When we cross the white canary with the red siskin the red pigment is missing in the offspring also. Both the yellow and the red pigment are total lost by a same mutation factor. This mutation factor in the canary inherits dominant. Duncker named this factor the "Fettstof" factor
O = Oxidation factor. The oxidation factor (black pigment factor) is according to Duncker the factor that gives the eumelanin its colour.
B = Brown factor. The third factor was named by Duncker the brown factor (brown pigment factor). The brown factor is the factor that gives the phaeomelanine its colour according to Duncker.
Pigment or feather structure?
Discussion: The experiments of Steiner and Duncker were made total independently. Later on a discussion between them showed a serious disagreement. Not about the practical breeding results but about the explanation of the cause of some new varieties. One of the new colour varieties was the olive budgerigar. This resulted in big differences of interpretation about the cause between the both scientists.
As early as 1906 dark green budgerigars with a blue sheen were found among the light green ones. Breeders preferred the light ones. The first olive budgerigar was bred in 1919 by Blanchard in Toulouse. This fancier was interested in minor colour deviations. He was very serious in his name giving. He bred the olive, but also the dark green out of olive and light green, with a cobalt sheen on the belly and the under tail coverts. This one was born from olive and dark green It was never known if he bred this olive by mating two dark greens.
Since 1921 the olive was bred in Germany and Swiss also. From the early breeding reports it turned out that there was a lot of confusion about this variety. The experiencies of fanciers were rather conflicting.
The discussion between Steiner and Duncker was about the brown factor.
Dunckers ideas: Duncker explained the peculiar colour of the olive colour variety of the budgerigar by the presence of an special pigment, the brown phaeomelanine. He thought that the olive colour was the result of loss of the black eumelanin and an increase of the phaeomelanin pigment formation. Canaries have both melanin pigments, eumelanin and phaeomelanin. Duncker assumed that this was also the case in parrots.
According to Steiner this could not be true. It was proven by Steiner that the budgerigar does not have phaeomelanin. Under the electron microscope only eumelanin but no pheaomelanin was found. Eumelanin and phaeomelanin grains are different in form and different in colour. Steiner did not find pheaomelanin. Not in the feathers of the olive and not in the feathers of the green wildtype.
He used an other way to prove the presence of melanin. Phaeomelanin is easy solvable in a dilute 2% potash acid solution. When feathers of a red brown chicken are placed in this solution a yellow brown colouring is seen after some minutes. This is the result of dissolving the phaeomelanin. Phaeomelanin is easy solvable. But it is very difficult to solve eumelanin. Also with a strong concentration of 45% is hard to succeed. The melanin in the feathers of the olive variety was hard to solve. There was no phaeomelanin found in the feathers. Not in the feathers of the olive, not in the feathers of the wildtype budgerigar. Phaeomelanin could not be the plausible explanation of the olive variety.
Steiners ideas: The idea of Steiner was that parrots have only one kind of melanin, the eumelanin. If increase of the phaeomelanin could not be not the cause of the olive colour variety, there had to be another explanation.
Research: Steiner found in his study with the electron microscope of cross sections of the feather barbs that the olive colour was probably due to another form of the feather structure. In the olive variety the depth of the layer that is responsible for the reflection of blue light, the cloudy zone (later called the sponge zone), was altered. The real cause was the narrowing of the structure of little channals that shapes the sponge zone. This was a clear outcome of Steiners research. The assertion of Duncker turned out to be false.
Breeding reports: His assunption that the olive variety is caused brought Steiner to analyse the breeding reports. Also he started an own breeding experiment and research about feather barbs. In this way he solved the problem of the cause and inheritance of the olive colour variety.
Three factors: This outcome of the results of the olive variety gave rise to his idea to suppose a special structure factor and he directed his research to the feather structure of all known colour varieties. Steiner distinguishes three groups of factors, that are responsible for the colours of birds: M=melanin factor, L=lipochrome factor ( now we speak in case of parrots about P=psittacine factor), S= structure factor. This classification is proved to be very suitable.
Theory and practice go hand in hand
We can learn from Steiner that writing of good breeding reports is very important for later study. Especially when new mutations arrive. The description of the first breeding results are important for later studies. How was the colouring of the plumage before selection is starting? How was the quality of the feathers? How are this birds mated during the first years? What were the results? Both breeders and researchers can benefit from the early observations.
We can learn also that the practice of bird keeping can take advantage of experimenting and scientific research. The scientist has methods and equipment to analyse feather structure and pigments. If he wants that breeders learn from his works he has the obligation to write in a readable way. Often the articles are so full of scientific jargon that they does not reach the breeders. Also intensify the content to problems breeders have .
It is important also that there is a good division of tasks. The mutation breeder is a daily contact with his birds, caring for his birds, mating the pairs, watching his birds, make notes about details, making of breeding reports sometimes name giving and experimentation. This all are part of the practice.
The scientist is needed for explanation. Underlying genetic aspects of developing new colour varieties. Insight in processes of pigmentation. Steiner and Duncker were bird fanciers and a scientists as well. They demonstrated that practice and research can go hand in hand.
Steiner brought new insight by his research. He pointed out (1935) that science is not yet so far that a complete and just classification of all colour change is possible. But his survey of genetic factors that play their role in the development of colour of the wild type and the altering of functions of the genes that are causing the different colour varieties is very useful today.
A very important aspect of his survey is the fact that the classification of Steiner is not restricted to green birds alone. He worked out a universal scheme for brown and multi coloured birds as well. It is also useful for brown birds who don't have barbs with a blue structure. Some birds don't have blue structure, other birds don't have red lipochrome, or miss the yellow pigments. A adequate classification counts for all this differences in genetic qualities in species. The classification by Steiner does.
Interesting fact is hat he praised Duncker because he who was one of the first scientists who made comparisons between different bird species. Duncker accentuated the ideas of Haecker to make a plea for research to compare the genetic factors of different bird species. The purpose is to study of the effect of genes in different species to find out what the real action is of genetic factors. This is an important issue today.
Postscript: Duncker was a fervent "genetic engineer". This was his strength but also his weakness. With the breeding of hybrids of the red siskin and the yellow canary he never reached his ultimate goal, to breed a red canary. He get stuck off copper coloured canaries. Today every canary breeder know that the diet plays an important role too. There was an American who discovered the role of carotene plays in the colour. Duncker did not dicover this fact because of his fixation on genetic factors.
Source: Hans Steiner: "Vererbungsstudien am Wellensittich, Melopsittacus undulatus (Shaw)", Habilitationsschrift Universität Zürich, 1932