KAGOSHIMA — Mount Sakurajima, an active volcano in Kagoshima Prefecture, explosively erupted 996 times in 2011, the most since record-keeping began in 1955, the local meteorological observatory said.

At the 800-meter-high Showa crater, which erupted in June 2006 for the first time in 58 years, 994 eruptions were observed last year. Two eruptions were observed at the Minamidake vent, which is at an elevation of about 1,000 meters, the Kagoshima Meteorological Observatory said Sunday.

Mount Sakurajima’s previous record for eruptions was 474 in 1985. But after erupting 548 times in 2009 and 896 times in 2010, its most recent string of eruptions means the record has been broken for three consecutive years.

The Meteorological Agency defines an explosive eruption as one accompanied by an explosive release of gas, ash or rock.

An office of the Ministry of the Environment in Tsushima, Nagasaki Prefecture, announced on Dec. 28 that it had succeeded in capturing the first ever footage of a Tsushima Leopard Cat on Shimojima island in Tsushima. Still photographs had been taken two times since March 2007, but moving footage is a first, says the office. (Mainichi)

Shigeyoshi Osaki can read the minds of spiders. Or so you would think, if you see the way he handles the eight-legged arthropods.

Hanging around: Professor Shigeyoshi Osaki demonstrates the strength of spider silk by swinging in a hammock supported by threads he harvested. SHIGEYOSHI OSAKI PHOTO

Osaki, professor at the department of biomacromolecules at Nara Medical University in the city of Kashihara, Nara Prefecture, is also one of Japan’s foremost researchers on spiders, especially spider silk.

When The Japan Times recently visited his office, where he keeps hundreds of spiders for research, he achieved the astonishing feat of harvesting silk from a spider with several-centimeter-long legs — right on cue.

First, he brought in a few paper cups, each of which had a spider and a twig inside. He then explained that he has to keep each of these harmless spiders separately because, if they are kept together, they would eat each other.

The two kinds of spider species he keeps are Nephila pilipes, distinguished by long, thin legs and coming from Okinawa, and Argiope amoena, which are caught in Kochi and Wakayama prefectures and bear a black and yellow striped pattern on the abdomen.

As soon as Osaki removed a rubber band holding a plastic net over a paper cup, a big spider crawled out of the cup and moved about across the professor’s body. With great skill and care, Osaki managed to let the leggy creature stay on his right wrist, then nudged it onto a black cloth, using a twig.

And then, with the wizardry of a dolphin trainer or snake charmer, he gently tapped the creature’s rounded belly with the twig several times. “It will come out soon,” he whispered — and whoa! — a fine, silver fiber spun out of the spider’s belly as Osaki pulled the twig away from the cloth, just like the sticky strings you get when you remove chopsticks from a bowl of natto fermented beans.

“The key is to approach them with a mix of tough and gentle,” he said. “If you are too strict, you will upset them and they won’t produce the silk. They can also pretend that they are dead.”

Silken tones: Professor Shigeyoshi Osaki plays a violin strung with spider-silk strings. TOMOKO OTAKE PHOTO

The author of numerous scientific papers, books and essays on spiders, Osaki says he first got interested in the arachnid while researching the adhesiveness of stickers for a paper manufacturing company some 30 years ago. He found spiders, which spin sticky orb webs to catch prey, much more exciting than stickers, he recalls. But back then, no one had really done in-depth research on spider silk, he said.

“Most researchers were studying spiders from a biological perspective,” he said. “Their biggest motivation was to find a new species, because if they did, the species would be named after them.”

Osaki, on the other hand, became fascinated with the unique characteristics of spider silk. In particular, the so-called drag line, from which spiders dangle, is strong, expandable and not so sticky compared to other silk threads. He says the drag line’s exceptional strength is due to its two-filament structure, noting that it manifests the species’ great survival skills, which are born out of its 400-million-year evolutionary history.

Osaki has honed his spider-silk harvesting skills over the years — through trial and error. He said he once released a bunch of spiders on a big tree in his front yard, only to find that most died because they ate each other or fell prey to birds. Also because spider research was for a long time only a side project — his main specialty being the analysis of bio-polymers such as collagen — Osaki could only find time to go spider-watching on weekends and at night. He would always take his two sons along at night, because, if he had gone alone, he said, he “could have been mistaken for a pervert.”

The native of Hyogo Prefecture has also created and fine-tuned his own silk reeling device. While he declined to reveal how he harvests silk now, saying it’s “top secret,” he conceded that he still does it manually. His earlier versions were made out of manually-bent steel coat-hangers, which were then attached to motorized Chupa Chup toys — designed to spin lolly-pops in one’s mouth — bought at ¥100 shops.

After collecting spider silk through such labor-intensive efforts, he went on to test its strength, by tying the woven silk to a hammock and dangling from it himself. The experiment, boldly carried out on the university campus in 2006, was witnessed by journalists and reported nationwide, along with a photo of the suited, 65-kg Osaki clutching the ropes.

Two Argiope amoena spiders with their silk. TOMOKO OTAKE PHOTO

Osaki said that several projects have attempted, both in Japan and overseas, to mass-produce genetically engineered spider silk, either by breeding goats that produce spider silk through milk, or by injecting spiders’ DNA into the genomes of silkworms. But for now, these projects are in their research phases, and none of the players involved, who have invested vast amounts of money, have yet to start manufacturing bullet-proof jackets or run-free stockings out of spider silk. Osaki, meanwhile, said he would rather stick to exploring the untapped potential of natural spiders.

Last year, he created violin strings with silk he had harvested, with the conviction that his violin would sound different from others. During the visit, he kindly played the special violin. Unfortunately though, his musical skills were no match to his silk-harvesting expertise, so it was hard to tell whether his slightly off-key rendering of the melancholic Japanese classic song “Kojo no Tsuki” (“The Moon over the Ruined Castle”) proved the violin’s excellence over a conventionally-strung Stradivarius. But Osaki says a spectrum analysis of the spider silk-strung violin has shown it has “milder” sounds than regular violins with synthetic fibers. In fact, a professional violinist in Germany recently contacted him, begging to let her play the special instrument, Osaki says. While he has turned down the offer, saying more research and improvement is necessary, he is certain that this would cast a new light on spider silk.

“The violinist was very eager, saying she wants to come to Japan to sign a contract any minute,” he said. “But I need to refine it to a level at which I can let others play with confidence. So I must keep on playing myself … until I find out how to improve it.”

I came across my first bumblebees of the season as they were busily draining the nectar from a broad swath of Blue Corydalis. The delicate flower stems nodding in a light breeze looked delightful in the sunshine, while above them frothy willow catkins were yellow with pollen and here and there birches were presenting hints of fresh green.

Variety incarnate: The species pictured here hint at the extreme diversity of Japan’s mammal fauna. The Sea Otter (above) is a North Pacific species. The Tanuki is a native of East Asia. ©MARK BRAZIL/IMAGES OF JAPAN

Then an iridescent Japanese Fiddle Beetle scurried across my path before several Peacock Butterflies and a gorgeous Blue Admiral Butterfly fluttered by, seeming to daub splashes of vibrant color on the leaf-litter wherever they landed.

Next, I spotted an Eastern Crowned Warbler flitting through the birches — a newly arrived migrant from the south that seemed more to squeeze out, rather than sing, its compressed, buzzing spring refrain: “Peetsu peetsu bzee.”

Sunshine and a brief spell of warmth after recent rain and weeks of cold since winter ended had tempted them all forth — and me, too. As I tramped the trails of Nopporo Forest Park in Sapporo seeking new signs of spring, what struck me most were the fresh signs of aliens afoot.

For starters, in the soft muddy sand of a streambed I came across a trail of long-fingered and long-toed prints indicating the recent passage of a Northern Raccoon.

Introduced to Japan during the late 1970s, raccoons have spread, causing havoc both for native environments and agriculture. Along with the likes of the Taiwan Macaque, Pallas’ Squirrel and American Mink, they are one of several relatively recent perturbations in the diversity of Japan’s mammal fauna.

However, diversity in adversity and isolation define both the fauna and flora of Japan. Its geological history, shaped by major subterranean forces as it rides the confluence of four tectonic plates, means that the archipelago has had a very chequered history that has given it an extraordinarily diverse natural history and an impressive suite of mammals — thankfully, most of them not alien.

In fact, more than 130 nonmarine (i.e. terrestrial, arboreal and flying species) and 40-plus marine mammal species are known from Japan, though it’s not thenumbers that are impressive but the different types of such animals that occur here.

Among these 170 or so species, for instance, there are a number of wide-ranging Holarctic species, such as the Red Fox and Brown Bear, in common with both North America and the great span of northern Eurasia. There are Palaearctic species too, such as the Eurasian Red Squirrel and Siberian Flying Squirrel, which range across Eurasia from Scandinavia to Hokkaido. Between them, these two groups lend an air of familiarity to Japan’s mammal fauna for European and American visitors.

Then there are the East Asian species, which are known from Japan and adjacent areas of the Asian continent, such as the Tanuki (Raccoon Dog) and the Sika Deer, which would be equally familiar to residents of northeast China, the Korean Peninsula, or eastern Russia.

But it is in the diversity of its more than 40 endemic species that Japan shows its true colors. These are species known only from Japan and nowhere else. Some range widely throughout several of the main Japanese islands, such as the Japanese Macaque, Japanese Hare and Japanese Giant Flying Squirrel; others occur only in small, isolated localities — and some only on small islands, such as the endemic Amami Black Rabbit.

Offshore, Japanese waters are also rich in marine mammal species. Seals, fur seals, sea lions, sea otters, dugong, dolphins, porpoises and whales range in their preferred habitats from the subtropical waters off the southernmost islands and the warm seas around southern Japan, to the cold current flowing south down the Pacific coast and the frigid waters of the Okhotsk Sea bordering Hokkaido.

Sadly, past human activity has already driven several species from Japan to extinction, including the River Otter and Japanese Wolf. Additionally, the more recent introduction of a number of “alien” species, such as Pallas’ Squirrel and the Northern Raccoon, may well lead eventually to further losses of native or even endemic species.

The Red Fox is found in the Holarctic ecozone, meaning the habitats found throughout the northern continents of the world as a whole. The Japanese Macaque (below) is endemic to Japan’s three main southern islands and Yakushima.?

The fauna of an island group is constantly in flux, shifting and changing naturally over immensely long periods of time, whereas human-induced perturbations happen very quickly and cause considerable disruption. How is it, though, that Japan has such a wide range of ingredients in its mammal species “cake”?

At times the Japanese islands have been connected to the Asian continent, with the Sea of Japan a mere inland lagoon, and connections northward via what is now Sakhalin to northeast Asia and southward via what are now the Korean Peninsula and the island of Taiwan.

Through complex processes, involving both tectonic movements and the planet’s pendulum swing between glacial and interglacial periods, at times sea levels have risen and caused the isolation of parts of the archipelago as long ranges of mountains, or even as isolated mountain-top islands (the Nansei Shoto today), where species have evolved in isolation.

At other times, the same processes have caused sea levels to fall, reconnecting long-isolated lands to each other and sometimes to the nearby continent via land bridges across which continental mammals have been able to immigrate and expand their ranges, hence allowing the populations of species in once-isolated areas to meet and mix once more.

From Kyushu to Hokkaido, the Japanese archipelago is dotted with active volcanoes reprocessing the building blocks of the islands, with eruptions occurring on some scale in most years. Visit Kagoshima Bay or Mount Aso in Kyushu, or the Akan National Park of eastern Hokkaido, to view and imagine the island-shaping forces of past megaeruptions. In Japan, temblors are frequent, often on a daily basis, tearing at the bedrock of the islands.

Tsunami occur fairly often, too, perhaps even annually, though their scale varies enormously and very few, perhaps only one in a millennium, reach the towering proportions of that monstrous wave generated on March 11 this year. Added to all that, typhoons batter the islands, particularly in the southern half of the archipelago, many times each year.

Rains dash, winds batter, sun bakes and ice grinds. Under such adversity, and in prolonged isolation off the east of the Asian continent, Japan’s geological and climatological history have combined to shape the land and to produce a tremendous range of habitat types and ecological niches throughout its more than 3,000-km-long archipelago.

Japan spans subarctic regions with sea-ice in winter in the north, and subtropical regions with mangroves and corals in the south. Its altitudinal range is such that it presents multiple climatic zones at the same latitude, meaning that it’s possible to hike from broad-leaved evergreen forest up into the alpine zone in just a few kilometers.

Homegrown: Unique to Japan, the Japanese Serow is found only on the three main islands south of Hokkaido.

As a result of these combined forces, Japan is home to a surprising array of mammal species — although almost a third of them are rather difficult to observe and identify, being mice, voles, rats, shrews and bats. But it is this considerable diversity, within the relatively small land area of Japan (approximately the same size as Germany, or slightly larger than New Zealand or the British Isles) that makes the mammals of Japan a fascinating pursuit.

Indeed, probe a little deeper and a tremendous regional variation among the country’s mammals emerges. Most of Hokkaido’s, for instance, are widespread species equally likely to be found in northeast Asia, with many not found further south in Japan. In contrast, most of the native mammals of the Nansei Shoto are endemic to those islands, and few species from the Japanese main islands range there.

Also, whereas Hokkaido shares affinities with northeast Asia, Nansei Shoto shares its with Taiwan and continental regions to the south and west. Meanwhile, in the main islands of Honshu, Shikoku and Kyushu, almost 50 percent of the mammals are endemic.

The unique mammal fauna of Japan faces particular issues in this partly over-crowded nation. Unlike in many other countries, these issues do not really include hunting for sport (it’s an uncommon, limited and declining pastime), nor is there a bushmeat trade driving animal populations down.

Nonetheless, habitat loss is a critical issue. The Japanese lowlands are so intensely developed for agriculture, industry and urbanization that few areas of natural lowland habitat survive — which makes each one precious.

The mountainous areas are less developed or disturbed, providing more plentiful habitat for species able to survive at higher elevations, but even there, habitat loss, or degradation, are issues to consider.

More recently, and compounding the issue of habitat loss, the introduction of alien species is causing difficulties for native species. Alien species, whether introduced deliberately or accidentally, occupy important ecological niches in a previously natural ecosystem; they may become predators of native species (mammals or otherwise), or they may compete with them for valuable resources such as food, cavities, den sites and so on.

Certainly, the introduction of alien species has far-reaching implications for the native mammal fauna, and deserves considerable attention from the conservation community.

Wherever in Japan you call home, there is a suite of local mammals to seek out. Even city parks support their own small and not-so-small mammals. If any reader knows of a regular place to see or watch the Masked Palm Civet (hakubishin), or has any photographs of them, I would be delighted to hear from you.

Volcanic areas showing increased seismic activity

BACK in January, Japanese seismologists warned that the tectonic plates colliding beneath the Pacific Ocean off the north-east coast of Japan were poised to slip catastrophically. By their reckoning, there was a 99% chance of an earthquake of magnitude 8.0 occurring off the Miyagi coast, and a 90% chance of one off Ibaraki prefecture, within the next 30 years. They were surprised only by the sheer size of the magnitude 9.0 monster that was unleashed when the plates at last let go on March 11th.

It seems that, on occasions, the rupture along this particular type of “reverse fault” (where the upper part of one side of the fault is thrust over the foot of the other) can jump across gaps and other boundaries along the fissure, linking up with other parts of the fault to extend the breach alarmingly. The traditional fault-segmentation model used in seismology does not allow for this. But on that fateful Friday, when the North American plate slid over the Pacific plate along a subduction zone running 130km (80 miles) off the Pacific coast of northern Japan, the shock leapt from the first segment to a second and on to a third, extending the fault zone some 400km and increasing its intensity more than 30-fold. With all the action taking place only 24km down, the seabed was thrust violently upwards, triggering huge waves.