(From the British Ecological Society Bulletin)
Vox Nori, Vox Orientalis - 1: cooing from Okinawa
Correspondence from M Tokeshi
As the first article from this British Ecological Society Bulletin correspondent in the Far East, let me start with something closer to my heart. My family line can be directly traced back to the mid 15th century on a small subtropical island of Okinawa, ca. 1000 miles southeast of Tokyo and the seat of the old Kingdom of the Ryukyus. This formerly independent island state thrived in shipping trade between Japan and China/South East Asia, one of the important trade items from Japan being dried giant kelp of the genus Laminaria, which is abundant in the north of Japan and constitutes a culinary basis of Japanese and East Asian cuisine. The happy days as an independent trading nation contributing to culinary development in Eastern Asia did not last long, however, with the invasion and subsequent annexation by Japan in the 17th century, devastation by the World War II and the occupation by the US military ever since. A little over 30 years on since the transfer of sovereignty back to Japan in 1972, Okinawa still remains socio-economically the most downtrodden area in Japan, with the lowest level of income and continued existence of vast US military bases. Given a background like this, it is not surprising to find that environments tend to come as the last element to be considered in the socio-political jigsaw of Okinawa. Hence, any good piece of news concerning the Okinawan environment is welcome for us environmentally-minded “Ryukyuites” at heart.
Okinawa as a subtropical island is economically poor but ecologically rich, though this richness is under constant threat. Here, I wish to share with you the story of an endemic flightless bird, Gallirallus (Rallus) okinawae. The Okinawa rail (or perhaps more in conformity with its Japanese common name, the “Yanbaru” rail) is endemic to the northern region (called ‘Yanbaru’) of Okinawa, known to science for less than 25 years. It is remarkable that a new species of bird larger than a pigeon was discovered in a developed country as recently as in the early 1980’s. The initially reported number of around 2000 birds has come down to a recent estimate of 1000 or less, being officially recognised as a species with a high risk of extinction in the near future. The threat to Yanbaru rails comes in different forms, including a reduction in habitable area due to logging of deciduous trees and land development, and predation by the mongoose Herpestes jevaicus which was introduced into Okinawa with a misplaced expectation of controlling the “Habu”, Trimeresurus flavoviridis, a deadly venomous snake common in Okinawa. Indeed, the mongoose shows little interest in the Habu and instead targets easy prey such as the Yanbaru rail and small mammals. With an increased incursion of roads into forest areas where the rail lives, the numbers lost to traffic accidents are also increasing. Another major threat comes from feral cats, mostly those abandoned by ‘compassionate’ owners who may travel substantial distances to quietly leave their kittens in a remote area such as Yanbaru.
Here come some heart-warming news against a backdrop of overwhelmingly sad history. The Kunigami village (195 km2 in area) in Yanbaru covers a major part of the rail’s distributional range and in particular the Ada district of the village encompasses an important habitat. The 210 or so inhabitants of this district have taken pride in their land, the rail being its symbol. What they did was to do whatever was in their power to reduce the loss of rails, particularly due to cats. In order to control feral cats, the villagers of remote Yanbaru decided to register their domestic cats in the district by resorting to veritable high-tech normally becoming of more developed areas of Japan ? microchip tagging. A tag measuring 2 mm in diameter x 10 mm long was inserted under a cat’s skin close to the neck. While the villagers’ domestic cats numbered only 10 or so, the scheme helped to raise awareness and other districts and villages soon joined the cat-tagging programme, resulting in over 500 cats being registered. This made it much easier to capture unregistered feral cats which were confirmed to feed on rails in the natural habitats. The culling of mongooses also started in 2000 by the prefectural government. In spring this year the villagers also established a rescue centre for injured rails by converting a former kindergarten building and letting it free to a group of veterinary doctors running a NPO animal hospital. Local children made an advertisement board for the centre. This centre will hopefully contribute to reducing the number of fatalities due to road accidents and predator attacks which claimed the lives of 11 rails in the last year.
Encouraging
though these efforts by local people may be, indications are that the grand
march towards extinction cannot easily be reversed. After all, nearly 25% of the rail’s habitat
was lost and its southern boundary of distribution was pushed 10 km northwards
in the 15 years to 2000. Indeed, some
people even estimate the current loss of habitat as 50% of the original. Nowadays the rail is no longer sighted in the
Oogimi village where the bird was commonly observed before the year 2000. This may be a general trend for
island-inhabiting flightless birds for which historical records of extinction
and near-extinction abound all over the world.
While I feel uplifted by the inspiration of fellow Ryukyu people in Kunigami,
there is no denying of continued uncertainty over the future of all living
creatures including the rails on this island.
My family has so far passed 14 generations in about 500 years, all
accompanied (or nearly so) by the cooing voice of the Yanbaru rail. How many future generations can have the same
privilege, no one can tell.
Following the above article on the plight of Yanbaru rail endemic to northern
Okinawa, I shall continue with more stories from the subtropical islands
of Okinawa in southwestern Japan. As I wrote before, the chequered history of
Okinawa for the past five hundred years or so made it a cultural crossroad
between north and south of eastern Asia, and east and west of the Pacific,
forcing upon it all sorts of human and natural exchanges and experimentation,
both intended and unintended. While some
of those ‘experimental’ processes helped nurture the unique Ryukyu culture,
others led to less desirable consequences. One of such unfortunate ‘mixing experiments’ concerns
the introduction of mongooses that I mentioned in relation to the Yanbaru
rail. A weasel-like carnivore, the Javan
or Indian mongoose Herpestes javanicus is widely distributed in Southeast Asia to the Himalayas and known for
its ability to attack and kill venomous snakes. It was for this reason that the species was first introduced into Okinawa
by a professor at Tokyo University (I don’t know whether he decided after
reading “Rikki-tikki-tavi” by Kipling) at the beginning of the last century
when no snake antivenom was available. From time immemorial the islanders of Okinawa have been suffering from
an abundant population of highly venomous Habu Trimeresurus flavoviridis. Indeed, until recently over 300 people in a
year used to be bitten by the snake while working in the field or in one’s
garden. The snake often occurs in close
proximity to country homes and it is not uncommon to encounter one inside the
houses, barns, etc. Though fatal cases are rare, the Habu-biting incidents still number about
100 a year in Okinawa and its potent venom combined with its aggressive
nature is feared and revered in the islanders’ mind. Indeed, as a souvenir from Okinawa one can easily purchase a bottle of
spirit with a pickled Habu in, considered as a source of good health and
long life (some prefer to say ‘aphrodisiac’ !).
Habu’s plight, or islanders’ plight with Habu, however, did not change much after the introduction of the mongoose. As were the cases with many well-intentioned introduction programmes the world over, this one also went awry with the mongooses adapting well to the new environment and enjoying a steady population increase over a century, but exploiting wrong prey, not Habu. After all, the Okinawan environment teems with small animals which have not experienced through evolutionary time predation pressure from such a fast and efficient predator as the mongoose. The forest of Yanbaru in northern Okinawa constitutes less than a third in area of Okinawa that in turn makes up a mere 0.3% of the total area of Japan, but this 0.1% of area harbours 25% of amphibian species, 33% of bird species and a whopping 42% of ant species of Japan with many endemic species including the Yanbaru rail Gallirallus (Rallus) okinawae, Okinawa woodpecker Sapheopipo noguchii and Okinawa spiny rat Tokudaia osimensis. It is unlikely that a predator capable of handling a potentially difficult prey like Habu should miss such an ideal opportunity to exercise its optimal foraging skills by concentrating on readily available, easy prey. Thus, instead of reducing the Habu populations, mongooses pose a threat to the biodiversity of Yanbaru by positioning itself at the top of food webs.
Apart from the threat to nature, mongooses have negative effects on human life by attacking another type of easy prey: farmed chicken. According to a recent survey, 20% of the chicken farms in Okinawa reported damages caused by mongooses, amounting to an estimated annual loss of up to £ 6000 per farm. An analysis of the patterns of damage revealed that mongooses often chose a particular route to a particular section of a particular cage or a particular farm building, and targeted in particular the young chicks of less than 30 days of age, a highly sophisticated optimal forager ! Apart from economic damages, the mongooses also pose a health hazard, as well over 50% of the animals were found to harbour Reptospira bacteria which, when transmitted through skin in rivers, ponds and paddy field contaminated by animal urine and faeces, may cause a debilitating, sometimes fatal, illness in humans. Transmission of rabies by mongooses is also a potential, though not confirmed, hazard.
The mongooses themselves may not count their fortune in Okinawa that high, though. Mongoose-culling operations have been in full swing, involving both local and central government as well as the cooperation of the US military. Indeed, the Japanese Ministry of Foreign Affairs solemnly announced that a (non-military) operation in the US training ground in the north of Okinawa (normally used for live-ammunition training) resulted in a total of 133 mongooses and 4 feral cats captured in fiscal year 2004, compared with 53 mongooses and 2 cats in the previous year. Presumably mongooses suffer less in this way rather than being crippled by stray ammunition on the wrong side of the training ground?
If one does not particularly fancy how mongooses are treated ‘officially’,
then we can turn to the news from the private sector of Okinawa. While many tourist attractions such as theme
parks used to feature highly-publicised shows of Habu-Mongoose duel (I remember
my family went to see one twenty or so years ago), the recent change in animal
protection legislation in Japan meant that such acts of cruelty as gratuitous biting
and hitting between animals, not to mention by humans to animals, can no longer
be legally staged as public entertainment.
This meant that the Mongoose the Winner on a dry ground in one theme
park was suddenly turned into a miserable wet creature exactly like Rikki-tikki
at the beginning of his story, as the new show that the park manager came up
with involved pushing an unsuspecting mongoose and a habu over the edge of a
pair of water-filled, parallel tubes of 10m long for a swimming contest ! Almost inevitably the mongoose ends up as a
loser despite his frantic effort to escape the watery medium as quickly as
possible, since the other contestant, Habu, is a natural swimmer ! If the park manager carefully read the
Kipling’s story, he/she may have understood that a mongoose in water is nearly
equivalent to a habu in sake.
If you have
read my two previous BES bulletin articles (if not, see http//:ambl-ku/) on the
indigenous fauna of my ancestral homeland Okinawa, a fascinating subtropical Far
Eastern island in the southwest of Japan, you may feel like visiting this small
island packed with both human and natural history. After a two and a half hours’ flight from
Tokyo, you will be immediately greeted first by rows of orchids at the Naha
Airport and soon realise that the best way to get around this island is to rent
a car, if you have a driving licence - Japanese or international. Yes, you can drive - Okinawa having been occupied by the ‘friendly’ US
forces for so long, the roads are well sign-posted in English. Of course
it will help greatly if you know some Japanese, as your ‘rent-a-car’ is almost
invariably equipped with a super-accurate, advanced car navigation system
complete with the soothing, sweet, guiding voice of a Japanese female ? the
system will not nag you even if you take a wrong turn; it will simply guide you
back nicely onto the right track using the most efficient route possible! Far more fascinating and ecologically
relevant than the car navigation system, however, when you rent a car in Okinawa
is a single sheet of paper handed to you together with maps, sightseeing guides
and discount vouchers for restaurants and souvenir shops. This colourful sheet features none other than
a beetle and is issued by the District Police in conjunction with environmental
protection departments of local and central government. But what is this beetle, and what is this
sheet all about? One should forget about
the images of familiar temperate zone beetles, as this one is absolutely huge
with body size reaching 60 mm and males possessing fabulous long forelegs.
This is the indigenous long-armed beetle, Cheirotonus
jambar, of Yanbaru (the northern forest of Okinawa island), the largest beetle
in Japan first discovered in 1983 and protected by law since 1985 as one
of the natural heritages of the country. Its life
history has been shrouded in mystery but research since then has revealed that
the larvae spend 3 to 4 years in a tree trunk and even remain for up to a year
in a pupation chamber after metamorphosing into an adult in late summer/autumn. The combination of long life history with
slow reproduction and limited distributional range (just in the north of
Okinawa), coupled with its mega body size, makes the species highly vulnerable
to ‘poachers’ who travel far and wide fully equipped with automatic logging
tools to hunt for this prized species. So this sheet of paper is distributed to every person renting a car in
Okinawa, with a stern warning that anyone illegally catching or in possession
of this magnificent insect will be prosecuted with a possibility of custodial
sentence and heavy penalty and people are encouraged to report to the police
any suspicious car(s) and person(s) acting ‘strangely’ in the forest
of Yanbaru. Yes, there are
many aficionados of insects in Japan, particularly of butterflies and beetles,
and some of these people are prepared to go to any length to catch the insects
they fancy, either for personal pleasure or for commercial gains. To our relief, since the anti-poaching
campaign began, illegal hunting and trading have apparently been
diminished. What is still worrying,
however, is non-illegal destruction and fragmentation of forests due to land
development and road construction, including plans related to military bases. For example, a suggestion of moving military
facilities from more populated (in terms of humans) areas in the central and
southern part of the island to the north poses a real threat to the indigenous
fauna of Yanbaru including the beetle.
Besides, a Yanbaru rail or a Yanbaru long-armed beetle that happens to
wander into the wrong side of the territorial boundary is not protected by the
Japanese law, as they fall under US military jurisdiction. With North Korea recently brandishing its nuclear card, the Japanese politicians
are more supportive of US military presence and hence more concessions
to the US proposals, which may in turn mean a higher probability of habitat
loss for the unique fauna and flora of Yanbaru. At least, an easier target ?
poachers ? is singled out for politically-viable protection measures.
Or so it seems. Crossing of borders by beetles is largely a matter of human making in Japan; you will understand what I mean if you pay a visit to any of large department stores, DIY shops and even some supermarkets around the corner. There you see a selection of big, exotic-looking beetles from all over the world, each in a neat but miserable plastic container with a small pot of solidified nectar, thanks to the recent change in trading laws allowing importation of live insects. Although booklets on how to take care and breed these beetles are easily available, the majority of these creatures are placed in the care of curious children and parents who are oblivious of the insect’s needs, and generally end up being chucked away as dead as enthusiasm gradually wanes with time since purchase and the insect in an unnatural, restricted space experiences a slow doom. Besides, released or escaped insects wreak havoc with native fauna, with an unknown degree of genetic mixing affecting local populations and sibling species, particularly those of rare status. The statistics are staggering: for example, in 2001 alone, 440,000 individuals representing over 400 species of rhinoceros-beetles and stag-beetles were imported live into Japan. This is a madness which must stop.
So I am utterly against the trading of beetles, though I like those gorgeous exotic beetles. But to be honest, I have to admit that the other day I enjoyed watching a TV programme featuring imported horned or rhinoceros beetles (which I guess would never be broadcast outside Japan). This was a grand ‘sumo’ tournament of the insect world, entitled “the World’s Strongest Insect Championship”, involving international participation of chunky beetle wrestlers from all over the world, including the largest species Dynastes hercules with a total body size (length) of 154mm. These large horned beetles are known for their aggressive behaviour, so a good sumo match between two contenders can be staged on a piece of wood, as they try to literally throw away the opponent with prowess of horn use and sheer strength. As people of my age and above have a happy childhood summer-time memory of playing with the Japanese rhinoceros beetle Trypoxylus dichotomus while munching away on a piece of juicy water melon, it must have been a natural occurrence for program producers to come up with the idea of a truly international, interspecific contest now that all these foreign species can be legally allowed into the land. After all, in the real world version of sumo, there are wrestlers from Russia, Bulgaria, Hawaii, Estonia and the current grand champion is of Mongolian origin.
The mega-coleopteran sumo contest simply involved simultaneously placing
two opponents in an arena on a log and the one that forcefully removed
the other from the arena was the winner. Quite similar to the human version,
these beetle sumo wrestlers face each other for a zen-like brief moment of
pre-fight calmness in the arena and then suddenly plunge into a fierce battle. The match is generally over within a minute,
as the one who succeeds in pushing and inserting its horn underneath the
opponent’s body and flipping it upwards to throw away the opponent secures a
win. Another similarity to the human
version of sumo is that only males are involved in this game, because females
lack a horn and are (as you can rightly guess!) less aggressive.
Contrary to the football World Cup, Europe is absolutely not represented in this tournament as it is of no significance in the world of mega-beetles. South America and Asia are serious contenders. In the quarter final, the Japanese Trypoxylus dichotomus beat the US Dynastes granti (now you know why I got excited about this TV programme; this was one of the rare occasions in which Japan beat the US in a ‘power’ game of any sort). Indonesian Chalcosoma atlas beat Thai Chalcosoma caucasus, Peruvian Dynastes neptunus beat African Augosoma centaurus and Brazilian Dynastes hercules beat Colombian Megasoma actaeon. In the semi final, Japanese T. dichotomus beat Indonesian C. atlas, and Brazilian D. hercules beat Peruvian D. neptunus. So the final was between the Japanese T. dichotomus and the monstrous South American D. hercules. As we reluctantly admitted, the odds were clearly against T. dichotomus; so it lost the first match but, to our surprise, won the second. So the final contest was left to the third and final match. It was a veritable ‘sensyuraku’ (the last day of sumo tournament), with a mixture of tension, pressure, surprise, and occasional good ‘throws’. In the third and final match, T. dichotomus was being pushed by D. hercules and close to the edge of the log, but in a brief moment of pause when D. hercules moved sideway, T. dichotomus shoved its horn under D. hercules’ body and threw the monster off the arena ? a win! This was how T. dichotomus was crowned as champion among horned beetles of the world. I cannot help but feel a little bit guilty of having enjoyed this show where contestants who are unlikely to meet in nature were forced to engage in a fight. But again, as ecologists, we do many experiments in which species are artificially mixed and competition is induced under somewhat unnatural conditions. A line must be drawn, of course, even if the terrain is unclear ? fortunately, at least the Yanbaru long-armed beetle was not called into the televised tournament, as it is under legal protection and, more importantly, it lacks a horn (like all good female individuals!).
After-note: my thanks to Lisa Belyea for encouraging me to contribute to the BES bulletin.