Authors: Tatsuaki Ishiguro
“Its principal food source is moss culled from serpentine, etc., and it spends nearly its entire time sitting motionless on the sawdust. Compared to ordinary mice or rats, its hair is thinner and has a reddish tinge. The short, hairless wings which sprout from its back have hardly moved within the Center’s environment.”
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Dissecting the sole captured winged mouse was out of the question and so research remained at the macroscopic level, but we should note that this did lead to close observation. Dr. Sakakibara was particularly interested in the mouse’s oddest external characteristic, its unmoving wings. In the
article quoted earlier, he posited the evolutionary importance of those wings and proposed several possible functions for them.
Figure 2
“With regard to the function of these short wings, given the weight balance, it would be hard to conceive of their evolution as an aid to flight as for bats. Given too the mouse’s thin hair and slow movement, one possible theory is that vibrating the wings helps the species survive the extreme colds of the Hokkaido environment. They might also serve, conversely, as panels to offload heat under hotter conditions, but either way there are sufficient grounds to suspect that the wings exist for temperature adjustment. For the sake of preservation, temperatures within the Center are maintained at a constant, and given the risks, it would be impossible to observe the mouse under long-term conditions of heat or cold, but I hope to clarify this issue in the near future.”
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Ultimately, according to Dr. Sakakibara’s own reckoning, he was unable to produce any significant results during the first three years of his term.
During that third year, however, there was yet another new development. Another winged mouse, and this time a female, was discovered by some children playing on the Kamuikotan Shrine’s premises and secured by the reverend, Yozo Sagawa. According to a city bulletin from that time, at the time of its discovery, “The mouse was clinging to a rock in the marshy area directly below the shrine’s precincts, as still as a corpse” (Reverend Sagawa).
As a result of this event, two projects were launched simultaneously. One was to pair Ai, the name chosen for the female, with Ponta to yield offspring. The other was a more involved and structured strategy for capturing winged mice than had previously been entertained (a major factor was the Environment Agency finally flexing some muscle in light of booming public interest in environmental issues). Since winged mice were neither prone to much movement nor to digging holes to hide, once spotted, even children could catch them.
With the help of a core group of students from
the Asahikawa College of Science, a comprehensive search was conducted once more in the Kamuikotan area, with its scope expanded toward Mount Taisetsu as well. While the team investigated Kamuikotan’s unusual ecosystem at the same time, no third winged mouse appeared. The report issued by the team when it disbanded went so far as to conclude, “Without a doubt the winged mouse is approaching extinction, and we hope that the two currently in captivity are not the last of their kind” (Professor Yoji Ogawa, Asahikawa College of Science).
Furthermore, there were also snags in launching the breeding plan. Since repeated incest did not interfere with the propagation of other mice and rats, Dr. Sakakibara initially had high hopes, but Ponta and Ai showed no signs of pairing even when they were kept in the same cage during the spring. Ordinarily, mice will breed prodigiously throughout the year, with the females capable of entering estrous on a regular basis, but no courting behavior whatsoever was observed. The predominant thinking was that the pair had exceeded their breeding age. The director of the Sakurayama Zoological Park, Hatsue Sakuma, who had succeeded at
other pairing projects in the past, was called in. She had the living conditions adjusted to approximate the animals’ natural habitat, but two years went by without any results.
“Of course we also considered artificial insemination, but we knew far too little about their overall behavior to proceed” (Director Sakuma).
The Committee for Species Preservation hastily assembled by the Environment Agency after its slow start also concluded, “Breeding of the winged mouse must be said to be extraordinarily difficult.” Since they could not rule out “the chance of mutual injury,” the two were moved to separate cages, and when the final attempts, by Kitanodai Veterinary Hospital’s Hiroo Sugiki, failed to bear fruit, the committee itself was functionally dissolved. In hindsight, it appears that insufficient attention was paid to the time of year, with only a series of random trials taking place.
One year later, the Environment Agency released a statement that amounted to a concession of defeat: “It is possible that the two winged mice in
captivity are the last of their kind.”
That was how the winged mice had been captured and studied up until the arrival of Dr. Akedera. Although there had not been any results to speak of, the report touted that, in addition to the winged mouse’s taxonomical status, some critical issues had been singled out, as follows:
1. Although it is unclear at what point the numbers of winged mice began to dwindle, on the basis of interview reports, it is believed that local sightings of the winged mouse began to decline within the past thirty to forty years. As there was neither any hunting of the species nor any easily conceivable change to their environment, the cause for their approaching extinction is unclear.
2. There are old tales of winged mice in the region according to which their bodies glow and their eyes shed tears when they palpitate their wings, but the behavior has not been observed in any winged mouse ever seen or captured. Our analysis of the winged mouse’s behavior is all
too deficient.
3. Although they are extremely lethargic and predominantly feed on moss, their breeding capabilities do not appear to be very high. Recently they are approaching extinction, but how they managed to protect themselves from natural enemies and to proliferate when nothing in their external appearance indicates any effective defensive measure remains of biological interest.
4. The wings’ function.
In the end it was Dr. Akedera who solved these riddles, but when he came on stage he was by no means expected to produce any glamorous results. In fact, to quote him on the matter, Dr. Akedera said afterwards that he had been summoned “to eat out the remaining innings of a losing game.”
Dr. Akedera graduated from Tokyo University’s College of Medicine in 1977. After obtaining his
medical license, he aimed to become a surgeon and underwent a two-year residency. Professor Tetsuichiro Muto, who had been his principal professor during that period, recalls, “He was more of a basic researcher than a surgeon, the type who suffers as a clinical physician precisely due to his gentle personality.” Immediately after completing his residency, he went abroad to study in the United States, and moving from one university to another, he began working on species specificity for viral transmissions. His work in the field earned him recognition, and he was invited back to Japan by an applied biology research center to head one of its departments. Over this period, he practiced little medicine.
In spite of what would appear to be an illustrious career, his academic reputation was not necessarily favorable. In part this owed to his clinical background, something of an oddity at the research center, but it is also true that he was accused of judging people too readily and of behaving too independently. Perhaps as a result, there were fewer people on staff in his lab than its size warranted, and by any prevailing standard, he was
given the cold shoulder when it came to funding. Yet, according to the person who was in the best position to understand his predicament, the secretary Mitsuko Tada, “Apart from the financial aspect the interpersonal issues didn’t seem to bother Dr. Akedera all that much.”
The breeding attempts abandoned, the Agency had turned to Dr. Akedera to see if the species might not be preserved at the cellular and genetic level via tissue samples. Dr. Akedera’s own records offer no clue as to why he accepted a project that was not, strictly speaking, academic, but he possibly felt that it might somehow contribute to AIDS research, which he was conducting at the time. Indeed, once the work on the winged mouse, which would not result in any papers, was complete, some unspoken agreement seems to have resulted in a significant amount of funding coming his way for his work on AIDS.
To start off, Dr. Akedera sent some cell culturing equipment, including a small clean bench, an incubator, and burners, on ahead before boarding a
flight for Asahikawa. He was met by Dr. Sakakibara at the local airport, which was ever rich with a forest fragrance. As they made their way to Fukagawa on a road bounded on both sides by lush, green rice paddies, they passed through Kamuikotan. Since a long tunnel had already been built by then, they were unable to take the riverside route that Dr. Akedera had been looking forward to.
Fukagawa is a small city that a five-minute drive will take you right through. The Species Preservation Center is located against a mountainside near the highway exit. Surrounded by forests near a marshy patch of land, the white-painted center has a three-story tower that at first glance resembles a warehouse or clock tower. The unique features in its architecture, especially in its crenellation, easily identify it.
Once you pass through the double set of doors, an insulating feature common in Hokkaido, you come upon a glass cage and the rather bizarre sight of the legendary Ezo Pickers, all-blue butterflies, fluttering around trees planted in the floor and reaching to the ceiling. At the rear is a large
water basin carved from serpentine in which a few of the last remaining Kamui salamanders lie quiet. In addition, animals that have been in the news lately like the Ishikari striped owl, the Sorachi long-tailed squirrel, the Hokkai bat, whose numbers are finally on the increase, and the Silver Cat, with its unique light-emitting hairs, grace their own spacious cages on a floor without any dividers. Each of the cages approximates natural environments and features an opening at the top, like the sunroof on a car, to admit natural light. Despite being quite a menagerie, there are few vocalizing animals so the floor is as marked by silence as by their feral presences. At that time, the booth for the winged mice was at the very back, surrounded by empty chambers whose nameplates promised a tissue culturing lab, a pathology lab, and a computer room.
(The following paragraph is based on Dr. Sakakibara’s recollections.)
As Dr. Akedera was led around, he stopped in front of the glass of the winged mouse booth. He observed the winged mice for a long time, taking
in the skin with so little hair, the feeble wings that looked like its extension, the slow movements, the relatively large ears, and the short tails.
Later, in a magazine interview, Dr. Akedera offered his impressions of the winged mice.
“I found it quite hard to believe that this was a species of mouse. It was almost as if evolution was proceeding backwards with those useless wings, the extremely sparse movements, and the lack of hair despite the extreme colds of the Hokkaido environment. The ears are large, but they don’t seem to react with any sensitivity to sound by shifting direction and would only serve to make the mice more identifiable to predators. For such a small, weak species to be facing extinction was, to my mind, almost a given.”
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Furthermore, in the journal he kept until the day before he died, he made the following entry on that date with regard to ordinary lab mice.
“The conventional wisdom of the scientific community
is that animals like mice have no sense of individuality. In particular, for pure strains of mice that are genetically identical, individual specimens are also objectively indistinct. There in that cage, if the marks on their backs were to disappear, or if you shuffled them with your hands, the creatures would be unable to regain the selfhood imposed on them from without. […] Matter, called the flesh, subsists upon death, and to that extent, what is lost in death is the massless entity called the self. If pure-strain mice know no self, then for them, who breed at such a frightfully prodigious pace, death does not exist either.”
Dr. Akedera was ready to commence his investigations from the first day, and that diligence would become a source of friction with the Environment Agency. As far as Dr. Sakakibara (and the Agency) was concerned, Dr. Akedera’s role was simply to preserve cellular and genetic information and not to resume the ecological research and breeding attempts that had been undertaken numerous times. It was assumed that one week would suffice for Dr. Akedera to fulfill his duty, so no funds were set
aside for any extensions.
From that very afternoon, however, Dr. Akedera’s activity demands included, at that late date, a thorough exploration of Kamuikotan. This would leave Dr. Sakakibara with the mistaken impression that Dr. Akedera was incensed that research personnel were being summoned only to be replaced one after another.