Red, the colour possessing the greatest power of attraction, projects the strongest visual energy, as the colour of the picture and the very heart of its being.
JÜRG SPILLER (1962) describing Paul Klee’s painting Blossom in the Night (1933)
There is no doubt that evolutionary biology has an implicit moral/ political message, not least for those who are not trained to guard themselves against these kinds of inferences or do not have an alternative moral framework firmly in place.
U. SEGERSTRÅLE, Defenders of the Truth (2000)
Persuaded by Duncker’s enthusiasm, Cremer arranged for workmen to start building three new bird houses at Rosenau to be completed in time for the 1927 breeding season. One of the new houses was for Cremer’s budgerigars, another for his exotic foreign birds, and the third for Reich’s and Duncker’s canaries. Cremer’s investment extended still further: he employed people to feed, water and clean the birds, and a full-time secretary to maintain the extensive breeding records. Duncker, spared any of the day-to-day responsibility, focused his entire attention on designing the breeding experiments and analysing their results. He was under some pressure to succeed since Cremer’s outlay had been considerable and, like all businessmen, he wanted results in return for his investment. But Duncker knew what he was doing. At the very least, by spreading his efforts across three separate projects he bettered his chances of success. And he had a hunch that the budgerigar’s kaleidoscopic colour mutations would be more tractable than the canary’s variegation genes.
Cremer’s wonderful facilities, unfortunately, failed to provide the right ambience to persuade the red siskin mules to breed together. Perhaps Dams and Matern had been lucky with their ‘doppelbastards’ or perhaps they had been lying – but Duncker and Reich could not persuade male and female red siskin mules to breed together, not in 1927 and not later.1 The female mules were unwilling participants in Duncker’s scheme and seemed to be dead from the neck down. Outwardly quite healthy, they simply showed no sexual stirrings whatsoever. It was as though they had no passionate parts. Duncker dissected a few, putting to good use the anatomical skills he had gained as a student, and to his amazement that is exactly what he found. Instead of a big, bold uterus and a cluster of yellow yolks, these birds were completely devoid of reproductive organs. Little wonder they didn’t lay eggs. They were like clocks with no clockwork.
The male mules were different. Several of them were bursting with rude passion fuelled by testosterone churning out of their full-sized gonads. But no matter how motivated the males were, if the females were sterile, there was little point in pursuing the original plan of trying to breed male and female mules together. On the other hand the success of Dams and Matern still rankled. But Duncker had seen enough to realise that even if he persisted and eventually found one or two fertile females, progress would be desperately slow.
Had he been able to reproduce Dams’s and Matern’s double hybrids, the red canary would have emerged fairly quickly. Duncker’s logic came partly from Mendel’s pea studies and partly from the practical experience of generations of bird keepers who knew that mules invariably resembled their finch parent rather than their yellow canary parent. In Mendelian terms, the genes for the finch’s plumage were dominant over those of the yellow canary. Duncker’s research with Reich in the previous two years had shown exactly the same to be true for canaries themselves: genes for the green plumage of the wild-type canary were dominant while the yellow genes of the domesticated bird were recessive.
If he could have persuaded two siskin mules to breed together, some of their offspring – three-quarters, he reckoned – would assume the red cardinal cloak of their siskin grandfather and the rest would be yellow like their canary grandmother. Duncker had also banked on another bit of Mendelian logic: some of the red offspring from mule parents would carry a double dose of red genes and therefore be even redder than their parents.
The female mules stubbornly refused to co-operate. Ever the pragmatist, Duncker modified the original plan and instead of starting with very red mules, he would use the coppery coloured birds he had already produced and back-cross them to canaries. The traditional back-cross involved pairing an individual with its mother, but it wasn’t necessary for Duncker to be quite so specific, he merely had to back-cross to a bird that was similar to the mule’s mother, a yellow canary. The coppery male mules were half siskin and half canary, and back-crossing these to a hen canary would yield offspring that were three-quarters canary and one-quarter siskin. But he would retain only the reddest birds and cull the rest. In this way he could simultaneously retain the siskin’s red genes but expunge nearly everything else that the red siskin had donated to its offspring. The next generation would be seven-eighths canary and one-eighth siskin, but still with red genes. This was the essence of selective breeding and precisely how generations of animal breeders, with no knowledge of Mendelian genetics, had produced wonders like the merino sheep and the cocker spaniel – with one important difference. No one had ever attempted to put the genes of one animal species into another.
Duncker and Reich prepared for the new breeding season by setting up cage after cage with a coppery male mule and a yellow canary hen. Progress wouldn’t be rapid, but the red canary was within their reach. Every day Reich removed and numbered the eggs as they were laid, replacing them with ceramic eggs, or sometimes ivory ones – remnants of an earlier era – placing the real eggs in special trays and keeping them cool until the hens had laid their full clutch of five or six. By returning the eggs to the hen canary only when she had started to incubate, they minimised the chance that the inquisitive male mule might peck them. Then, after four days at 40ºC under the hen’s brood patch, Reich took the eggs out of the nest again and candled them. By holding the egg up to a strong light – in truth a candle was barely bright enough – he could see whether it was full and fertile with a developing embryo, or clear and unfertilised.2 It was a frustrating time: only a few eggs were fertile. But Reich and Duncker expected this; they knew it wasn’t going to be easy and clear eggs were part and parcel of mule breeding. They threw them away and allowed the birds to breed again, hoping for better luck with the next clutch.
The few fertile eggs were placed under the care of canary foster-parents; old, experienced birds known to be reliable breeders. Fostering is a standard management technique among bird breeders that increases the chances of the chicks’ survival. By taking the eggs from the siskin-canary pairs it speeded the production of offspring by encouraging them to lay again. Reich and Duncker waited for the chicks to hatch and for their feathers to emerge so they could see what colour the new hybrids were. It took almost two months for the new feathers to appear and, as every mule breeder knows, the waiting must have been intolerable. Siskin mules were late breeders and the offspring sometimes didn’t attain their true colours until November. But when the moult was finally done Duncker was disappointed again. Instead of the Mendelian ratios of red and yellow birds that they expected, these second-generation mules looked much like the first, reddish – bronzy, brassy, coppery, but certainly not crimson. The onus lay firmly on Duncker’s shoulders; Reich and Cremer made no claim to understand genetics, the red canary was Duncker’s baby and they were looking to him to bring it into the world.
While the red canary was experiencing a difficult gestation, the budgerigar project was in obstetric overdrive, generating results faster than Duncker had ever imagined. Cremer was ecstatic and each evening when Duncker appeared after his teaching day was over, he was updated on the results. The purpose of their collaborative research was to work out what to expect when budgerigars of two different colour types were crossed. There were twelve recognised budgerigar varieties in 1928, many of them with different genetic constitutions; the project therefore required several hundred different test matings, each employing several pairs of birds. As with the canaries, Duncker found that the budgerigar’s plumage colour was controlled by a number of different factors and by working out how these were inherited it wasn’t long before he could perfectly predict the outcome of any mating. Because green plumage, for example, was dominant, a pure-bred (or homozygous) green bird mated to either a yellow or a blue bird would only ever produce green offspring, and because blue was recessive, two blue parents would only ever produce blue chicks. Other types of pairings produced different coloured chicks in different proportions and large numbers of offspring were needed to check these ratios against the predicted Mendelian values.3 Such was their enthusiasm for this project that in 1926, soon after they began to collaborate, Cremer and Duncker, with a handful of others, launched the German Budgerigar Society – which continues to this day.4
It isn’t difficult to imagine Duncker walking home from Cremer’s house at dusk along Bremen’s leafy streets, thrilled with their results and planning the papers he would write. And just as soon as there were enough chicks from a particular pairing to be sure of the results, Duncker began writing. These were wonderful and exhilarating days, for the budgerigar’s colours were, as he suspected, as easy as Mendel’s peas. The results were published under Duncker’s name, but usually with a note acknowledging that the research had been conducted ‘in the aviaries of Generalkonsul C. H. Cremer’. Their findings were quickly translated and transmitted around the world to universal acclaim. For the average budgerigar breeder Duncker had created order out of chaos; breeding budgerigars would never be the same again.
By the end of 1927 Duncker had published over twenty scientific articles on bird genetics. His major discoveries were sent to the Journal für Ornithologie, where Erwin Stresemann was the editor. Stresemann was also a canary enthusiast and, rather than dismissing domesticated birds as having no relevance to bird biology, as many other ornithologists did (and still do), he actively encouraged Duncker. Stresemann was smart enough to realise that while ornithologists would dearly love to know about the inheritance of colour in wild birds this was utterly impractical, but by letting Duncker pave the way with canaries and budgerigars, he was building a firm foundation for future researchers.5
Duncker also wrote more accessible accounts of his work for bird keepers’ magazines like Gefiederte Welt. A good populariser, he made every effort to ensure that amateur bird keepers with little or no training in biology could understand his results. Cremer fully supported Duncker in this goal by hosting meetings for scientists and bird breeders at his Rosenau home. In 1927 Duncker decided to establish his own journal with the explicit aim of bridging the gap between scientists and amateurs, and putting the whole business of bird keeping on a more scientific footing. This was no trivial undertaking and Vögel ferner Länder (Foreign Birds) became the official organ of the German bird keepers’ society – the AZ. Prior to this the society journal had been a thin and poorly produced affair, but in taking it over and renaming it, Duncker transformed it into a top quality publication for his and other researchers’ findings. Appearing quarterly, the first volume contained over 200 pages of articles recording its members’ attainments. Cremer became the AZ’s president, leading the society onwards and upwards with what the membership fondly called his ‘golden Rhineland humour’. The society’s journal went out to every one of its 423 members. Thanks to Duncker’s papers and his visionary editorship, Vögel ferner Länder opened new horizons and unimagined opportunities for discovery among Germany’s bird keepers. Duncker contributed the first article, ‘Inheritance and the Breeder’, and no less than five others, including one on his red canary venture.6
On 26 May 1928 Hans Duncker celebrated his forty-seventh birthday. His teaching career was going well and was greatly enhanced by his growing scientific reputation. He was a popular teacher and started a small museum at school based on the skins of exotic birds that died in Cremer’s aviaries. Duncker added canaries and budgerigars of different colours from his own experiments in the hope of encouraging some of the boys to take an interest in genetics. At the same time, in the barely overlapping circles of science and amateur bird breeding, Duncker’s status was also growing. His prodigious stream of publications was making it clear both to ornithologists and bird keepers alike that Duncker knew more about the genetics of bird colours than almost anyone else.
The period of economic stability that had begun around 1924 was all too brief. By 1929 the political situation in Germany had started to deteriorate once more. Unemployment rose from 1.8 to 2.8 million in a single year; terrorism was widespread and inflation once again raged out of control. Following an aggressive election campaign in September 1930, Hitler’s National Socialist party, to everyone’s surprise, secured 18 per cent of the vote. The Weimar Republic retained the majority and were still in control, but only just. Thereafter the economic and political situation deteriorated rapidly, aided by the Wall Street crash and by Nazi thugs rampaging through Berlin’s streets smashing the windows of Jewish shops. Germany was tearing itself apart economically, socially and biologically.
The German people were restless and receptive to the notion that regeneration could be achieved through scientific knowledge. The idea that society might be improved through an understanding of genetics had been around for at least forty years, introduced under the name of eugenics by Francis Galton.7 In Britain it remained just an idea, but in the United States eugenic theory had been put into practice during the 1920s and people deemed unfit to reproduce were sterilised – supposedly for the good of society as a whole.8 Eugenic ideas were also well entrenched in Germany thanks to the popular writings of certain influential biologists, and during the depressing years following World War I, the possibility of improving society – the ‘Volk’ – seemed especially appealing. Germany felt it could no longer afford the humanitarian luxury of supporting ‘degenerates’. Eugenic ideas were rendered even more palatable through crude but seductive economic arguments and the apparent success of similar policies in the United States.
One of the main architects of the eugenics movement on the other side of the Atlantic was the canary geneticist and arch-Mendelian Charles Davenport, whose muddled paper on inheritance of colour and crests Duncker had wrestled with in 1923.9 Back in 1902 when Davenport had negotiated his position as director of the Station for Experimental Evolution at Cold Spring Harbor, he had told his sponsors that his programme would help in the ‘improvement of the human race by better breeding’. Once in place, he started to address the then uniquely American problem of human race mixing. His investigations led him to seek the genetic basis for a wide variety of human traits, including eye and hair colour as well as pauperism, criminalism and the sailor’s love of the sea. Some of these studies would be laughable were it not for their appalling social consequences. By the time Galton was knighted in 1909, Davenport had completely embraced his predecessor’s idea of improving the human race and was embarked on an ambitious study of ‘feeble-mindedness’. He soon became a leading figure in America’s eugenic movement and part of the faction that favoured the compulsory sterilisation of the feeble-minded in order, as Davenport said, to ‘dry up the springs that feed the torrent of defective and degenerate protoplasm’. To halt the degeneration of society, as he saw it, he also advocated the restriction of immigrants into the United States. The notorious Immigration Act of 1924 assessed over 80 per cent of eastern and southern Europeans seeking to immigrate as ‘feeble-minded’ and refused them entry. During the 1930s US immigration officials sent back large numbers of Jewish refugees anticipating the Holocaust for the same reason. At the time that Duncker was wrestling with the red canary, Davenport had become president of the International Federation of Eugenics Organisations and was rubbing shoulders with the likes of Eugen Fischer, the German Professor of Anthropology who later provided ‘scientific justification’ for Hitler’s attempted eradication of the Jewish people.
Because the eugenicists believed that differences between races and between individuals were wholly genetic – and hence unchangeable – the process of ‘improving’ society through selective breeding seemed to them at least both straightforward and highly desirable. Others, however, highlighted the utter fallacy of eugenic beliefs. The former British prime minister, Arthur Balfour, for example, said that if the fit survive, all that means is that those who survive are fit. Consequently the eugenicists’ worry that ‘the biologically fit are diminishing in number through the diminution of the birth rate’ must be wrong by the doctrine of natural selection. . . . If families of the professional class were ‘so small that it is impossible for them to keep up their numbers, they are biologically unfit for this very reason’.
In Germany eugenics originated in the late nineteenth century with high-profile scientists like Ernst Haeckel, a committed Darwinian and great populariser of science. Haeckel did more than merely promote evolutionary thinking. He treated Darwin’s natural law of selection as a social law and declared that different human races represented distinct levels of evolution. ‘The lower races such as . . . the Australian Negroes’, he wrote, ‘are psychologically nearer to the mammals – apes and dogs – than to the civilized European, we must therefore, assign a totally different view to their lives.’ Haeckel’s book Die Welträtsel (1899) (published in English in 1900 as The Riddle of the Universe) sold over 500,000 copies in Germany alone, and led to a much greater misappropriation of science in Germany than in either Britain or America, and it did much to create a uniquely German form of social Darwinism. However, it was their fiercely nationalistic view of society that distinguished German eugenicists from the more liberal, individualist eugenicists of Britain and America.
Haeckel’s other popular book Lebenswunder (1904) (published in English as The Wonders of Life in 1905) anticipated and epitomised the German eugenicist view:
The history of civilization teaches us that its gradual evolution is bound up with three different processes: (1) association of individuals in a community; (2) division of labour among the social elements, and a consequent differentiation of structure; (3) centralisation or integration of the unified whole, or rigid organisation of the community. The same fundamental laws of sociology hold good for association throughout the entire organic world.
The ideas of Haeckel and his followers, that some races were more worthy than others, that society could be improved and that individuals should work for the common good, were so pervasive that by the 1920s there was, as the political scientist George Stein put it, very little left for National Socialism to invent. ‘German academics and scientists did, in fact, contribute to the development and eventual success of national socialism, both directly through their efforts as scientists and indirectly through the popularisation or vulgarisation of their scientific work.’10
Duncker was also drawn to the notion of improving the German people through scientific knowledge, especially genetic knowledge. It appealed to his sense of national identity and made him feel as though his scientific skills were serving society. Moreover, his faith in genetics was unshakeable – if his knowledge of heredity and artificial selection had enabled him to improve domesticated birds, why shouldn’t the same principles be applied to people? His troubles with the red canary were temporary and he was confident he would soon find a solution.
The failure of the red siskin mules and yellow canaries to yield the predicted offspring was both disappointing and puzzling. The alleles had not segregated in the straightforward way Duncker expected and he could only conclude that the genes that controlled the canary’s yellow plumage somehow interfered with those of the red siskin to create rusty rather than red offspring. Duncker saw it as a battle between yellow and red. If he could only eradicate the yellow, the red would shine through. He thought it all out again and weeks later had an answer. The way forward, he now felt, was to avoid yellow canaries altogether and use white ones, which have no yellow genes, to create a new cohort of red siskin mules. If his assumptions were correct, then in the absence of yellow genes the red would have to predominate.
There were two types of white canary to choose from. Though superficially identical, genetically they couldn’t have been more different. One type possessed white genes, which were dominant over those controlling the normal yellow plumage, while in the other the white genes were recessive to the yellow. It was the dominant white genes that Duncker was after.
What were almost certainly dominant white canaries had first appeared in Germany around 1660. Johann Walter painted one and physician Schroeckius, Baron Pernau and Rosinus Lentilius had all written about them.11 German dealers had carried them on their backs to the Paris bird markets, where Hervieux had seen them. Very few white canaries ever made it to England, but Eleazar Albin, smart operator that he was, had included a picture of one in his book. But rare mutations are always vulnerable to extinction and after a brief period of popularity these white canaries disappeared – the mutation simply died out and it wasn’t until nearly 200 years later, in 1908, that white canaries spontaneously re-emerged. Remarkably, they did so simultaneously in two separate stocks about as far away from each other as was geographically possible: in New Zealand and in England. Test breeding revealed, however, that in both cases the white plumage of these birds was recessive to yellow and they were called ‘recessive whites’.
Then, in 1918, another white canary cropped up, this time in Germany and out of ordinary green roller canary stock. This proved to be a different mutation, one in which the white plumage was dominant to the usual yellow plumage. Carefully nurtured, this mutation, known as a ‘dominant white’, was quickly established and proved to be extremely popular. The Germans propagated them so successfully that by 1924 dominant whites were being widely exported across Europe. Meanwhile the recessive white canary had all but become extinct; those in Britain had disappeared completely and only a handful of the New Zealand whites, imported into Europe in 1925, had survived. Duncker managed to see a few of them and realised that the two types actually differed very slightly in their appearance. The recessive birds were pure white, but the dominant white birds had yellow ‘shoulders’, and we can see from Walter’s painting of 1657 and Albin’s from 1731 that the original German mutation was also a dominant white bird. It was on this mutation that Duncker now pinned his hopes.
If he used white canary hens and red siskin cocks, Duncker was convinced the canary’s dominant white genes would completely suppress any yellow ones and allow the siskin’s red to express itself. He also predicted that this pairing would produce mule offspring of which half would be red and half orange (Figure 5). The reason for this was that the dominant white canary cannot exist as a ‘pure’ mutation, since individuals with two dominant white alleles always die before they become sexually mature (Figure 5, top). All dominant white canaries capable of breeding therefore carry only one allele for white plumage, which is dominant, and a recessive yellow allele, which is not expressed.12
More siskins were ordered from South America. When they arrived, Duncker and Cremer set up the pairings with the white canary females and again waited for the chicks to colour up. And for a third time they were thwarted. Certainly, the hybrid offspring were of two colours, but not the red and orange Duncker had predicted. Instead, they were either copper, just like the previous mules, or ash-grey – rather like the female red siskin. Duncker described the season’s results in a paper in Vögel ferner Länder and included a beautiful colour illustration painted for him by Karl Neunzig,13 the editor of Gefiederte Welt, depicting a male red siskin, a white canary and the two types of very disappointing offspring.
FIGURE 5 Duncker’s genetic schemes for predicting the outcome of particular pairings. Top, the expected results from pairing two dominant white canaries: note how those offspring bearing two white alleles (far right) do not survive; bottom left:pairing dominant white and yellow canaries; bottom right: pairing a dominant white canary and a red siskin.
Duncker was beginning to lose interest in the red canary. He simply could not understand why his experiments did not work. His logic was impeccable and his approach was scientifically exemplary, but the siskin’s red genes were much more difficult to capture than he ever imagined. As we’ll see, it wasn’t just the genes that were a problem.
Despite the setback with the red canary project, this was still a productive time and 1929 saw the publication of his book Genetik der Kanarienvögeln (Canary Genetics), which became an instant success. It was what canary breeders had always wanted: a scientifically sound step-by-step guide to their breeding efforts. Through the book and his other publications, and as a result of secondary reports in magazines like Cage and Aviary Birds in Britain and the American Cage Birds, news of Duncker’s research reached out around the world. His discoveries were an inspiration to canary breeders everywhere, even inside the American penal system, where they encouraged Robert Stroud – the ‘birdman of Alcatraz’, incarcerated alone for fifty-four years – to create his own coloured canaries.14 Duncker’s book allowed canary breeders for the first time to predict with complete confidence the kind of offspring they would get from pairing particular combinations of birds. Now that breeding canaries to order was relatively straightforward, fanciers wanted a new challenge and the red canary project captured their imaginations. Fanciers around the world launched themselves into it with unbridled passion.
