‘Vent sexing’ is, in the simplest terms, the technique of sexing one-day-old chicks based on the visual detection of the presence (male) or absence (female) of a bump on the cloaca, the anal vent. It was developed in Japan in the late 1920s and first described in English translation by Masui and Hashimoto in 1933 [2]. That same year, the Japanese [Chick] Sexing Association (JCSA, 日本雌雄鑑別協會, Nippon shiyū kanbetsu kyō) was formed from the amalgamation of various regional organisations. The JCSA quickly established a school to train commercial chick sexers (‘雌雄鑑別師’, shiyū kanbetsu-shi, ‘male–female discriminators’, or simply ‘鑑別師’, kanbetsu-shi, ‘discriminators’) that took in both male and female students [3].

The ability to sex chicks at such a young age instead of at several months, as in traditional methods, was transformative for the poultry industry, representing substantial savings in the cost of feeding what was regarded as unproductive male birds—money that could be applied to the rearing of increased numbers of productive female birds. The introduction of vent sexing in Japan in the late 1920s is said to have led to a 20% increase in egg production in 5 years [4].

"Japanese chicken and flowers (1862)" by The Metropolitan Museum of Art is marked with CC0 1.0.

For an account of the arrival of the first chick sexers sent by the JCSA to Britain that places this in the context of the Japanese presence in the UK as a whole, readers are referred to Keiko Itoh’s book ‘The Japanese Community in Pre-War Britain’, and for the thoughts and experiences of one of the chick sexers, there are the diaries of Koichi Andoh, translated by his son Takayoshi and organised by author Stephen Curry in ‘Mr Andoh's Pennine Diary: Memoirs of a Japanese Chicken Sexer in 1935 Hebden Bridge‘ [5]. My focus in this article will be primarily on the British reaction to the sexers’ presence as recorded by period newspapers, illustrating the way in which this coverage was indicative of changing British views about the Japanese people and nation.

The first JCSA mission arrived in Britain in late 1933 at the invitation of a local poultry breeder (W D Evans—see below). The mission consisted of two men, Umata Komatsu (小松馬太, Komatsu Umata, 50 years of age) and Mitsuo Nishitani (西谷光男, Nishitani Mitsuo, 26 years of age) [6]. Before arriving in Britain, the two men had been in Rome to demonstrate the venting technique to delegates at the 5th World’s Poultry Congress, under the patronage of Benito Mussolini. Komatsu was a nikkei (日系, overseas Japanese) who had lived in the USA since a child; at one time, he and his wife and three daughters owned a poultry farm in Fresno, California. Komatsu had already worked as a chick sexer in the US in 1932 [7]. Nishitani, meanwhile, was a graduate of Tokyo University and writer.

"Chickens" by perpetualplum is licensed under CC BY 2.0.

Although the arrival of the JCSA mission in the UK went unreported at the time, this all changed once they got to work, and so, in the spring of 1934, at the height of the hatching season, several stories appeared in the British press, focusing on Nishitani. A story in the 20 April 1934 edition of the [Yorkshire] District News, described him as a ‘brisk and alert’ 26-year-old from Nagoya with ‘a gift for quickly adapting himself to his environment’. The report also includes the first instance of what was to become a running theme in stories about Japanese chick sexers: the idea that there was something about the Japanese ‘race’ that made them particularly well-suited to the task; although, in this instance, Nishitani himself is said to be the author of the remark.

This aligns with Eiichiro Azuma’s statement in his study ‘Race, Citizenship, and the “Science of Chick Sexing”: The Politics of Racial Identity among Japanese Americans’ [8].

The day after the District News story appeared, the Daily Mirror ran a piece that included a photograph of Nishitani and expanded on what made this technique the unique domain of people of Japanese heritage [9].

The Daily Mirror also reported that Nishitani was one of two chick sexers engaged by W D Evans. Curiously, the newspaper quotes Evans as saying that the other sexer was named ‘Ito’ [10]. Was this Komatsu, and Evans simply got the name wrong? If so, it is an odd mistake to make. To confuse matters, the following year, Evans employed a sexer by the name of Masashi Ito and it is possible that he was the ‘Ito’ from the previous season, too. Komatsu was also back working for Evans in the 1935 season, having travelled to the UK a second time in the autumn of 1934 after returning to Japan in the late spring of that year (via the US). Nishitani left the UK for Japan via Canada in October 1934; although he would continue to be involved in chicks sexing, he did not return [11].

Regardless of the identity of the second chick sexer in Evans’ employ in the spring of 1934, across the spring and summer of that year, British newspapers continued to report on the work of these ‘Eastern Magicians’. Again and again the question as to why the Japanese as a people were so skilled at this technique was raised, with answers given that were not only of a questionable racial basis but also flew in the face of the facts—in 1934, vent sexing was under 10 years old as a technique, yet one newspaper told its credulous readers [12]:

Public Domain, https://commons.wikimedia.org/w/index.php?curid=16744459

The language being used draws from the Western fascination with Eastern mysticism in general and ‘performance magic’ in particular, and finds an almost exact parallel in Robert Henry Elliot’s explanation of the origin of the skills of the ‘oriental magician’ in his book ‘Myth of the Mystic East’ published the same year (1934) [13].

As Christopher Goto-Jones points out in ‘Conjuring Asia: Magic, Orientalism, and the Modern World’ [14], Elliot was with this explanation trying to deny to ‘Eastern’ magicians’ any inherently superior skill to ‘Western’ magicians less as a claim to the universality of human traits and more as a way of championing the ‘Western’ trait of constant innovation over the ‘Eastern’ trait of the rote learning of old formulas.

One can detect the same defensive tone in the period press’s recall to the use of magic and mysticism to describe the skills of the Japanese chick sexers when they first arrived in Britain. At the same time, it has to be acknowledged that the vent sexing approach itself, with its reliance on manual manipulation of the young chicks, ideally single-handed and at speed, was strongly reminiscent of the sleight-of-hand for which Japanese stage magicians were known—not for nothing was one the most commonly used words for stage magician in Japan at the time and since ‘手妻‘ (tezuma), which translates as ‘hand lightning’, which is to say, ‘lightning [quick] hands’ [15].

What was unquestionably not magic was how real those skills were. A post-mortem examination of a test batch of sorted chicks confirmed that the sexers could achieve a 97% accuracy. This success led to a call by people like Evans for ‘sex-determination stations’ to be set up across the country—provided enough Japanese experts could be enticed to the UK. Evans said in his Daily Mirror interview that he hoped to bring ‘ten or twenty’ Japanese experts to the UK in 1935 [16].

Across the 1934 and 1935 hatching seasons, large-scale hatcheries like Evans and Sterling Poultry Limited mounted more and more demonstrations of the efficacy of the technique, driving demand for more experts in the ‘Japanese method’ [17]. This was aided by the speed at which trained chick sexers could work: 500 chicks sexed per hour, with an accuracy of 95% [18]. The benefit to poultry farmers was such—‘pullets’¬ (young female chickens) sold for 10 times the price of ‘broilers’ (young male chickens) [19]—that experts commanded high earnings. In 1935, in the UK, Japanese chick sexers were said to earn 1.5–2 d per chick, or as much as £25 a day [20]. To put that in perspective: that same year, the average agricultural worker in England and Wales earned 34 shillings a week [21].

Although the Japanese chick sexers themselves did not get to keep all of that £25 a day (see discussion below), it is still little wonder that courses claiming to teach the ‘Japanese method’ began to be advertised in British newspapers as early as January 1935 [22]. The drive to adopt the technique quickly took on a jingoistic approach with reports later that year that the National Poultry Council was planning to set up a ‘Chicken Sexing Control Board’ that would issue licenses with the aim of ‘…replacing the Japanese by British sexers’ [23].

Evans himself was asked if he would take on [British] students. His reply was blunt [24].

This desire to see Japanese sexers replaced with British sexers in some ways runs counter to Itoh’s thesis that one of the reasons that the Japanese community in the UK did not experience the same hostile reception as, say, the Chinese community, was because their presence was not seen as a threat to British jobs [25]. However, at the same time, the number of Japanese chick sexers in the UK (discussed below) was never very high, so any resentment at their presence can be regarded as an outlier that did not impact feelings towards the Japanese community as a whole and must be balanced against the desire of British poultry breeders for them to be employed.

Regardless, the Chicken Sexing Control Board was duly set up, and the first examination was held on 31 December 1935. It was a disaster; only five candidates applied (four men and one woman), none of whom met the accuracy requirements [26]. The whole idea was abandoned—for now [27]. This failure, like similar failures in the USA [28], reinforced racially centred ideas of the innate superiority of the Japanese in the ‘art’ of chick sexing that the Japanese sexers were happy to exploit. Japanese chick sexers retained their effective monopoly—even the announcement in early 1936 of the development of a technical solution that would ‘abolish the need for employing expert chick-sexers, mostly Japanese’ did nothing to challenge their dominance in the short term [29].

Public Domain, https://commons.wikimedia.org/w/index.php?curid=24765645

Across the next few years, dozens of Japanese chick sexers operated in the UK, although accounts vary as to the exact number that were in the country at any one time. The Daily Herald claimed in February 1937 that there were ‘over fifty of the Japanese experts in the country’; the following year, Ernest Brown, Minister for Labour, answering an MP’s question in the House of Commons said that ‘According to the information in possession of my department, there are 18 Japanese chick-sexers employed with permission in this country’; a year later, a hatchery owner called G G Belfield stated that he currently employed 16 Japanese experts [30]. The number appears to have varied between 15 and 25 a season and included both sexers contracted to the JCSA and sexers contracted to a rival organisation, the ‘International Chick Sexers Association’ (ICSA), the existence of which Ernest Brown may have been unaware [31]. In 1937, the JCSA dispatched a total of 36 sexers to other countries [32].

Searching records of passengers arriving and departing from the UK allows the identification of around 50 individuals from Japan who worked as chick sexers in the UK in the period 1933–1942 (see Appendix); however, this list should not be seen as exhaustive, having been assembled primarily by searching for the term ‘sexer’ and ‘poultry’ in online records. It is also the case that not all of these individuals were in the UK at the same time, although, a number of the names appear multiple times in the lists, representing repeated journeys between Japan and the UK from one hatching season to the next.

An examination of the list reveals that the sexers who travelled to the UK were, for the most part, in their mid to late twenties, although a few were still teenagers, and others, like Komatsu, were well into middle age. At least one of the sexers was a woman, Sui Okutomi (奥富すい, Okutomi Sui), who came to the UK for the 1937 hatching season while still a teenager. Okutomi can be seen in her school uniform in a film shot by the JCSA in 1936 and made to be shown at the 6th World’s Poultry Congress in Leipzig [33].

The exchange in the House of Commons described above marked a return of concerns about Japanese chick sexers taking jobs from British workers [34].

A few days later, a newspaper editorial pointed out that an examination had been held to find Englishmen who could do the job and none had passed [35]. Employing British sexers was simply not—yet—a viable alternative. Ernest Brown’s reply to a question from another MP quoted in part above is worth quoting here in full because it touches on the issue of how much of the money that poultry breeders were paying for chick sexing services was finding its way into the hands of the chick sexers themselves [36].

The minister was being disingenuous; this ‘salary of £1 a week’ was simply the retainer that the Japanese sexers were paid regardless of the number of chicks they sexed, their actual earnings were this plus the fee they received per chick [37].

Although a substantial fee was being paid to the organisations for whom the sexers worked, a more realistic appraisal of the actual earnings of the sexers themselves would be £20 to £25 a week [38]. This aligns well with the information that the JCSA-contracted chick sexers were guaranteed an income of at least £350 a season (which lasted three to four months) and transportation to and from the UK.

To put this in perspective: the men were earning around 10 times what they could for the same work in Japan, a country where the cost of living was 10 times lower than that in the UK [39]. This income also aligns more or less exactly with reports that Japanese American chick sexers were earning $1,700 a year in this period, there being around $5 to the £ in the mid-1930s [40]. The activities on which the sexers spent ‘freely’ included tennis and golf, the favoured sports of expatriate Japanese businessmen [41].

Across this period, although there were periodic spasms of protectionist order paper rattling in Parliament protesting their employment rather than that of British sexers, their carefully cultivated indispensability insulated them from prohibition. However, this could not last.

By Allen Saalburg - United States National Archives, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1593944

The most immediate impact of the outbreak of the Second World War on the employment of Japanese chick sexers in the UK was that the journey to and from Japan for the 1940 season was made much more difficult. This is evident from the fact that six of the sexers in the UK for that season travelled home first class, an extravagance unthinkable before the start of the conflict and presumably motivated by the need to get the men home on the next available ship, whatever the expense [42]. They would have arrived back in Japan in late September, just as news of the signing of the Tripartite Agreement between the Empire of Japan, Germany, and Italy broke. By the following Spring, the only sexers left in England were seven members of the ICSA who had opted to stay in the country between hatching seasons rather than make the trip back to Japan (their names are given in the Table below). The 1941 hatching season was the most lucrative these men had ever known, as they were without the usual competition from the JCSA sexers [43]. However, any thought that the gamble to remain in the UK had paid off would have been shortlived.

The internment of the seven sexers who had remained in the UK, alongside many other male Japanese residents and visitors to the UK, in the days and weeks following the outbreak of the Pacific War marked the beginning of the strangest chapter in the story of Japanese chick sexers in the UK. This first period of internment was to prove brief, as in late January to early February 1942, the seven sexers were re-released to work the 1942 hatching season. This brought immediate condemnation and threats of a boycott of any business that employed them; however, the press made clear why the decision had been made [44,45].

What is remarkable is not that there were objections from British poultry workers to the men’s release but that these objections again centred as much on the fact that these men were being freed ‘to earn big money when British chick-sexers are being called up for the army’ as they did on the idea of having ‘the enemy on their farms’ [46]. That is not to say that feelings were not running strong against the sexers for their nationality alone [47,48].

In this regard, three of the sexers went on to bring trouble on themselves, as the following article from 3 March 1942, which I quote here in its entirety for its unintentionally absurdist effect, makes plain [49].

Within two weeks of this story breaking, it was being reported that the National Poultry Council had asked the government to re-intern the seven sexers and was dis-avowing any involvement in their original release [50]. However, the fact remained that the British poultry industry needed the men, as their internment records show that they were not re-interned until two months later, in June 1942—the end of the hatching season [51]. Regardless, the damage was done. As events would show, whoever had asked for the men to be released for the 1942 hatching season would not be making the same request the following year.

For four of the seven sexers (see Table), their re-internment was to prove equally brief, as they were amongst the 70+ Japanese subjects interned in the UK who were included in the July 1942 Anglo-Japanese Civilian Exchange [52]. They left the UK finally on 29 July 1942 [53].

The other three sexers remained behind. In the case of at least one of them (Masami Yasue), this was apparently by choice, as repatriation was voluntary [54]. It is almost certain that the three men believed at the time that they would be re-released, perhaps permanently, in advance of the 1943 hatching season, but this was not to be; all three men remained in internment until 1945. Although it was certainly the case that there were increasing numbers of competent British chick sexers available by 1943 [55], it is hard not to read this lack of a second release as the result of the furor triggered by the golfing incident the previous year. The sad irony is that it is more than likely that none of the three sexers who suffered as a consequence of it was involved in it [56].

The post-war period falls outside the scope of this work. However, it is worth remarking, in closing, that Japanese sexers began to trickle back into the UK within a couple of years of the end of the war—indeed, the three sexers interned in 1942 were released in time to work the 1946 season. Hatcheries that, in 1945, boasted of having ‘Sterling-trained’ British sexers, by 1947, were happy to say that their chick sexers were Japanese-trained, and by 1948, were open in their employment of Japanese sexers, leaving the newspapers to return to their old, familiar cry of ‘are there no British sexers available to do the work?’ [57].