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Western Australia (西オーストラリア)

Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

During September 2003 and August 2004, I stayed in Perth, western Australia, to learn ecological rehabilitation after mining. I hope you can read Japanese, and please read Japanese pages. In Hokkaido, northern Japan, most coal mining sites were closed, due to economical reasons. I am planning to apply the Australian rehabilitation techniques to Japanese mining sites.
Alcohol (in Japanese)



Australia's wildlife

Australia's wildlife inhabits a land that is the oldest, lowest, flattest (and except for Antarctica) the driest continent on earth. These characteristics, together with long isolation and an unpredictable, difficult climate, have molded the animals and plants of Australia into a rich and diverse community of living things with a unique 'down under' stamp evident in almost every member. Australian manmmals, for example, are dominated by marsupials, animals that raise their undeveloped young in a pouch. Though the group has members elsewhere in the world, only in Australia does their unique lifestyle so dominate the landscape. Such popular animals as the koala are found nowhere else. Another group of mammals, the monotremes (the platypus and echidna), is entirely confined to Australia and New Guinea. Much the same is true of Australia's wealth of birds, reptiles and frogs. About 750 species of birds, 700 species of reptiles and several hundred species of frogs call the island continent home. Most are found nowhere else. Many of the birds (especially parrots and honeyeaters), and some of the reptiles are common, conspicuous and easy to observe almost anywhere.
Perhaps Australia's most popular and best-known animal, the koala is unmistakable. Koalas eat only the leaves of a few species of eucalypts (gum trees), a fact that has far-reaching implications on their distribution and lifestyle. They are widespread in coastal and near-coastal forests in eastern Australia (roughly from Cairns to Adelaide), but their range is very patchy, partly because their fussy diet means that only certain kinds of forests meet their needs. Eucalypt foliage is indigestible and low in nutritional Yalue. To help them cope with such difficult fare, koalas have (in proportion) the longest gut of any animal, and a notably lethargic life-style - they spend about eight-tenths of their Lives sleeping and most of the other two-tenths eating. Though they remain common in many areas, the species is threatened by urban sprawl and forest clearing.
The largest of all marsupials. an adult male Red Kangaroo stands about the height of a man and may reach 85 kg in weight. Females are often only half this size or less. Males are usually a dull red in color and females bluish grey (they are widely known in the bush as ‘blue fliers’), but this is not invariable: males are sometimes bluish grey. and in some areas females are reddish like males. Found right across inland Australia, wherever the average annual rainfall is 500 mm or less. the Red Kangaroo is the most widespread of all kangaroos. It feeds mainly at dawn and dusk, usually spending the day loafing in the shade of small trees. It is often seen in small groups, but mobs sometimes form under a range of circumstances. Of all kangaroos. the Red Kangaroo is the one best adapted 10 deserts and drought - yet for food it relies on grass, the resource that vanishes most quickly when the rains fail to arrive. Such a precarious lifestyle has resulted in a range of special adaptations for coping with drought.
One crucial adaptation to combat drought conditions is an unusual reproductive strategy known as embryonic diapause. A mother Red Kangaroo mates again almost immediately after giving birth; but the embryo resulting from this second mating is blocked from development (‘pauses') so long as her first joey remains in her pouch. When this youngster finally approaches weaning, only then does the later embryo resume normal development. This is an extremely effective device for coping with a drought-prone environment. It means that, if conditions are good, her parental investment can be promptly switched from first to second youngster without any of the conventional delay in finding a mate for a second breeding attempt. On the other hand, if conditions are bad. breeding can be abandoned and the mother has lost little because her investment in the second embryo is minimal. Either way, the mother is in the best possible position to cope.
One of the most remarkable consequences of this unusual situation is that it often confront the mother with the necessity of suckling two youngsters of very different ages simultaneously). As in humans, the chemical composition of the mother’s milk changes markedly over time to match the changing needs of her growing infant. Baby kangaroos each have their own teat in their mother's pouch. All they have to do is hang on, while she manages the extraordinary chemical juggling trick of delivering the right infant formula to the appropriate teat.
One crucial adaptation to combat drought conditions is an unusual reproductive strategy known as embryonic diapause. A mother Red Kangaroo mates again almost immediately after giving birth; but the embryo resulting from this second mating is blocked from development ('pauses') so long as her first joey remains in her pouch. When this youngster finally approaches weaning, only then docs the later embryo resume normal development. This is an extremely effective device for coping with a drought-prone environment. It means that, if conditions are good, her parental investment can be promptly switched from first to second youngster without any of the conventional delay in finding a mate for a second breeding attempt. On the other hand, if conditions are bad. breeding can be abandoned and the mother has lost little because her investment in the second embryo is minimal. Either way, the mother is in the best possible position to cope.
One of the most remarkable consequences of this unusual situation is that it often confronts the mother with the necessity of suckling two youngsters of very different ages simultaneously). As in humans, the chemical composition of the mother’s milk changes markedly 01er time 10 match the changing needs of her growing infant. Baby kangaroos each ha\'e their own teat in their mother's pouch. All they have to do is hang on, while she manages the extraordinary chemical juggling trick of delivering the right infant formula to the appropriate teat.
The Eastern Grey Kangaroo is found in Tasmania and across most of the eastern half of Australia. It is especially common wherever open forest is interspersed with grassy glades. Like the Red Kangaroo, it feeds largely on grass, but is generally found in areas of higher annual rainfall (250 mm or more), and it is common in many coastal localities. Like the Red Kangaroo, it is supremely well adapted to drought conditions, and its whole life-history is geared to coping easily and efficiently with unpredictable feast or famine.
The Eastern Grey is nearly as big as the Red Kangaroo; males may weigh up to 66 km and females up to 32 km. It can be told by its greyish fur, but at close range ii is also the only kangaroo with a furry muzzle. However, it looks very similar to the Western Grey Kangaroo, and in some parts of the country the two occur together. Telling these two species apart is not easy (the fur of Western Greys tends to be faintly brown in hue, whereas Eastern Greys are very distinctly grey). The Eastern Grey Kangaroo lives in groups consisting of several females and their young of various ages. Fully mature breeding males lend to live apart.
The birth of an Eastern Grey Kangaroo is typical of many other kangaroos. Usually only one young is born at a time, though twins have been recorded. About tl1e size of a human thumbnail at birth, and weighing well under one gram, the young kangaroo is naked, blind and almost helpless. It finds its way unaided through the forest of its mother's fur to the safety of her pouch, where it promptly clamps onto one of her four teats. There it remains for about 36 weeks. It ventures tentatively from the pouch at first, but forays become longer and longer until it finally quits the pouch for good at around 45 weeks. It is weaned at about 50 weeks of age.
Though by far the most familiar 10 most people, the Red Kangaroo and the Grey Kangaroo are by no means the only members of their clan. Australia has several dozen less familiar species of smaller kangaroos, wallaroos, wallabies and various other close relatives. Zoologists usually refer to them all as macropods, purely for the convenience of bundling them all up together under a single name.
Among the largest of these is the Common Wallaroo. Typical features of its habitat include rocky cliffs, escarpments and cases to provide shelter from sun and rain. It is common in most kinds of forest and woodland and wherever such features are present. It occurs in two populations that look so different they have distinct common names ('wallaroo’ in coastal districts and ‘euro’ inland) but genetic studies demonstrate they are indeed the same species despite external appearances. Wallaroos often stand with their shoulders thrown well back and the elbows lucked in, which gives them a characteristic stance, obvious at some considerable distance. As with kangaroos, males are very much bigger than females, and their lifestyle is strongly drought-adapted. but they are much more solitary in behavior.
The Tammar Wallaby is confined to about ten islands off the southern coast of Australia and a few mainland districts in southern South Australia and Western Australia. It is especially common on Kangaroo Island. During the day it shelters in dense coastal scrub, emerging at night to feed in open grassy areas, including camping grounds. Solitary in nature, it seldom forms groups except for mothers and their young. One of its extraordinary characteristics is that it seems able to survive indefinitely on sea water for drinking. It is also unusual among macropods in having a distinct breeding season: young are born mainly in January and usually leave the pouch in October.
The rock-wallabies are a distinct group with a number of special features consistent with a life among cliffs and boulders. They are very much more agile than other wallabies, long-tailed and sure-footed, with broad, rough soles for better traction. Numbering about16 species, as a group they are widespread across Australia (except Tasmania), but individual species are often confined to a very small area. The handsome Yellow-footed Rock-wallaby is relatively widespread compared to most members of its group, with populations occurring in the Flinders Ranges of South Australia, in western New South Wales and in some remote parts of south-western Queensland.
Marsupials are perhaps most obviously characterized by the fact that mothers rear their young in a furry pouch on the abdomen. Marsupials make up the bulk of Australia's mammal fauna. In Australia, this single group has evolved to fill an extraordinary range of habitats and lifestyles, in the trees. on the ground, and even under the ground. One of the many tree-dwellers is the Common Ringtail, which inhabits east coast woodlands, including (sometimes) suburban parks and gardens. Once widespread on the mainland but now confined to Tasmania. the Tasmanian Devil is about the size of a small dog. Solitary and surly in disposition, it is the largest of Australia's surviving meat-eating marsupials (the extinct thylacine was much bigger). It is nocturnal, and feeds mainly on carrion. The Northern Brown Bandicoot is common in coastal Australia from near Sydney northward to Cape York and west to the Kimberley. It is nocturnal. nearly omnivorous, and often visits suburban gardens.
Marsupials may be better known, but monotremes are equally distinctive and also uniquely Australian. There are only three species, the Platypus and two types of echidna. Most widespread of these is the Short-beaked Echidna, which occurs in forest and woodland almost everywhere in Australia, as well as southern New Guinea. Unmistakable because of its spines, the echidna is usually solitary, active by day, and feeds entirely on ants and termites. Adults are about half a meter long and weigh around seven kilograms.
The dingo's ancestry has been traced back some 6000 years to the Indian Wolf. Over several millennia, the breed was carried by seafarers throughout southeastern Asia, and ultimately to Australia perhaps 3500-4000 years ago. Evidently a much more successful predator than any other on the Australian continent, it spread rapidly throughout the mainland, though it seems never to have reached Tasmania. Its spread was probably helped by the Aborigines, who valued it for its help in hunting, and also as a sort of pre-technological substitute for the electric blanket.
Appearance varies widely, but a typical dingo is sandy or gingery in color, with pricked ears and a bushy tail. Dingoes howl but do not bark. They are flexible predators, and may occur in packs or as solitary wanderers. The dingo is subjected to considerable persecution from farmers and stockmen in many parts of Australia, but the major threat to its survival is probably interbreeding with feral dogs. Already in many areas truly purebred dingoes are rare, most individuals show the unmistakable signs of hybridization with domestic dogs.
TOO BIG TO FLY Largest of native Australian birds, the Emu stands about two meters high and weighs up to 50 kilograms. The sexes arc similar in appearance, but females are usually somewhat larger than males. The Emu is common across Australia in a wide range of habitats. It is numerous in open grasslands and present in most areas except the harshest deserts and thickest forests. It browses on a wide range of plants, and also eats insects such as locusts. Unlike the kangaroo, it is sensitive to drought and it needs frequent access to water. Courting couples stay together for up to five months but, once the eggs are laid, the female wanders off, leaving the male to incubate the large green eggs and raise the black-and-white-striped chicks unaided. The size of the clutch va1ies to some extent with the availability of food, but up to 24 eggs have been recorded in a single nest. A typical egg weighs a little over half a kilogram.
Emus are mostly seen alone or in small groups, but they often move away from an area under drought (sometimes for considerable distances), and then large mobs may form. They move with a slow, stately, deliberate pace but when alarmed, they break into a flouncing trot; at full gallop they can reach 48 km per hour. Emus are usually quiet, but they sometimes utter a low, hollow booming note. They are extremely curious, and will often approach to investigate any unusual sights.
WATERLAND WANDERERS Both the Darter and the Little Pied Cormorant feed on fish, but they differ strikingly in their method of catching them underwater: cormorants chase their prey, while darters lie in wait for it. Both birds are common on wetlands throughout Australia; the cormorant is also abundant around the coast. The Black Swan also occurs on wetlands almost everywhere (including ponds in city parks), but it is more common in the south of the country. Black Swans feed mainly on the roots of aquatic plants, reaching underwater with their long necks.
Next, perhaps, to the Emu, the Australian Pelican must surely rate as one of Australia's most unmistakable birds. It also ranks, along with the Black Swan, as one of the heaviest that fly. Big and boldly pied, it has an enormous bill with the lower mandible uniquely modified into a large rubbery pouch. Some oilier waterbirds have a small pouch which they use essentially to carry food, but the pelican uses his to actually catch it. Floating on the water, it reaches under with its bill, extending its pouch to scoop up a gallon or so of water, then squeezes the water out, leaving the fish behind to be swallowed (almost all other fish-eating birds spear their prey). Most pelican breeding colonies are on lakes in the arid interior, but the birds disperse widely when not breeding, and may be seen along the coast or on any suitable wetland around the country. Properly known as the Black-necked Stork but known almost everywhere as the Jabiru, Australia's only stork is a tall, stately bird that might be encountered along the margins of wetlands almost anywhere, but is very much more common in the north than in the south, and especially common in the Top End. It feeds on aquatic animals of all kinds, from fish to frogs to snakes. Females resemble males except that they have yellow, not brown eyes.
Parrots and cockatoos
Harboring more than 50 species, Australia is often billed as the 'Land of Parrots'. Typical of this vivid and motley throng is the Crimson Rosella. which is common in dense forests all along the eastern seaboard from the Cairns area south to Victoria. It often occurs in suburban parks and gardens, and many a forest picnic table has its own group hoping for handouts. Adults are unmistakable, but youngsters sometimes cause confusion because they are dull green and may form flock., restricted 10 their own age group. The King Parrot roughly parallels the Crimson Rosella in appearance, behavior, habitat and distribution. but differs most obviously in its blue (not red) rump and smooth green upperparts. Cockatoos constitute a group of parrot species whose most obvious characteristics include large size, raucous calls and a conspicuous crest. One of them, the Sulphur-crested Cockatoo, is widespread in northern and eastern Australia, including Tasmania. It inhabits most kinds of forest and woodland, including city parks and gardens. Ringnecks arc very similar to rosellas in size, appearance and general habits, but inhabit woodlands of the arid interior, whereas rosellas are more characteristic of coastal districts. Black, green and yellow are the chief plumage colors, but the bird gets its name from a crescent of pale green around the nape. Most flamboyant of all the parrot clan, perhaps, is the Rainbow Lorikeet, which is abundant in coastal forests of eastern Australia and the tropical north. Lorikeets feed mainly on nectar, and the typical image of lorikeets is of screeching flocks rocketing through the treetops on their way from one grove of flowering trees to another.
Australia has approximately the same number of species of songbirds as any other temperate region of comparable size and climate, but a conspicuous difference lies in the fact that most Australian songbirds are found nowhere else. Many are common, conspicuous and colorful. Making up in the vigor and melody of its song what it lacks in colorful plumage, Gilbert's Whistler inhabits arid woodlands of the southern interior. It is named after John Gilbert, a notable early figure in Australian natural history. An intrepid explorer, he was one of the casualties of Ludwig Leichhardt's disastrous journey to Cape York in 1845. The Superb Fairy-wren is a vivacious feathered mite of the more open woodlands of south-eastern Australia. It needs open areas for foraging and bushes for shelter. Green lawns and ornamental shrubbery suit its requirements very well, and it is common in many city parks and gardens. The Superb Fairy-wren breeds in groups rather than in pairs: the female builds her nest and incubates her eggs unaided, but all group members join forces lo feed and care for her young.
The Rainbow Bee-eater is abundant in open country throughout Australia. Wherever there are bare earthen banks (such as river banks or rail cuttings), the bird nests in loose colonies, laying its eggs in a chamber at the end of a burrow dug out by both parents. As its name suggests, the bee-eater does indeed prey on bees, as well as a range of other large flying insects such as dragonflies. The Mistletoebird is also widespread across Australia, wherever mistletoe grows. The fruits of these parasitic plants constitute virtually its sole diet, and it has a uniquely structured gut to digest them. The relationship between bird and plant is symbiotic, because the plant relies on the bird to spread its seeds, which the bird drops unharmed after digesting the surrounding pulp. New Guinea is widely known as the home of birds of paradise, but several species are unique to Australia. One of these, Victoria's Riflebird, inhabits dense rainforests on the east coast between Townsville and Cooktown mid the adjacent Atherton Tableland.
The Laughing Kookaburra is the largest and heaviest of all kingfishers. but it is best known for its dawn and dusk choruses of loud rollicking laughter, as neighboring clans gather at the limits of their communal territories to reinforce their boundaries.
Kookaburras live permanent groups consisting of a dominan1 male and female and a variable number of 'auxiliaries' that share routine nesting chores such as feeding the young. These helpers are usually the full-grown young of earlier broods that remain with their parents more or less permanently instead of dispersing to rear their own young as 'conventional' birds do. How it is that the young can possibly profit from this self-imposed slavery is a fascinating question that has attracted a great deal of research. Whatever the complexities, their total contribution is far from trivial: helpers invest a third of all time spent incubating kookaburra eggs, and more than half of all food fed to nestlings is fetched by adults that are not their parents.
Kookaburras live in open woodland (including city parks), not necessarily near water, and they feed mainly on ground-dwelling reptiles and insects, which they capture by pouncing from a low perch. The species is widespread in eastern and southern Australia, and has been deliberately introduced to Tasmania and locally around Perth, Western Australia. There are in fact two species of kookaburras in Australia (and several others in New Guinea): in the tropical north of Australia the Laughing Kookaburra is largely replaced by the similar Blue-winged Kookaburra, which has pale eyes, a more up-turned bill, and much more blue in the wings.
The Estuarine or Saltwater Crocodile is one of the mere handful of Australia's genuinely dangerous animals. There is no shortage of poisonous snakes, some deadly. Few, however, pose a serious threat to humans unless molested or se1iously provoked - but any full-grown crocodile is a potential man-eater. Although occasionally seen at sea, this impressive animal is most at home in tidal estuaries. However, mature crocodiles tend to disperse to freshwater swamps and floodplains during the annual wet season, returning in the dry. A typical adult crocodile measures about four meters from snout to tail tip. but big males may reach seven meters and, rarely, even eight meters.
It is widespread in India and south-east Asia, and in Australia occurs in coastal districts throughout the tropical north. Southern limits on the cast coast are hard to de6ne because wandering individuals frequently stray well beyond the normal limits of distribution, but occurrences south of about Rockhampton are unusual.
Crocodiles are solicitous parents. The female lays her eggs – 40 to 60 or so - in a large mound of mud and plant debris. Then guards them carefully until they hatch about 100 days later. The hatchlings squeal as they break free of the egg and the mother then carefully digs them out and carries them in her mouth to the water. There they congregate with other broods to form creches guarded by an adult baby-sit' throughout the first few weeks of life.
The Estuarine Crocodile became seriously endangered before hunting was banned in the 1970s. Some threats still persist ( many drown, for example in the nets of fishing trawlers). hut populations have generally recovered well, mid crocodile viewing now constitutes a popular tourist attraction in many tropical rivers across the north.
OPEN AND SHUT Nearly as much a national icon as the koala and the emu, the Frilled Lizard occurs in southern New Guinea as well as right across the northern half of the Australian continent, soutl1ward almost to New South Wales. Common in most kinds of savanna and open woodland, it spends a great deal of its time in trees, feeding mainly on cicadas and similar large insects. Adults reach nearly a meter in total length, much of which is tail. The famous frill consists of a sort of cape of loose skin stretched over a series of stiff cartilaginous rods surrounding the head. These normally extend backwards along the body. An intricate linkage connects this array with the muscles of the tongue in such a way that when the animal opens its jaws wide in threat, the same action also moves the rods erect, causing the frill to spread. The whole complicated apparatus works a little bit like opening and closing an umbrella. The display is used as a kind of bluff, intended to startle any attacker, and to make the Frilled Lizard look very much bigger and more formidable than it really is. It is normally used only when hard-pressed: the Frilled Lizard usually first responds to danger by climbing a tree and flattening itself against the trunk, looking as much like a slab of loose bark as possible.
Goannas and other reptiles
About 19 centimeters long, the Thorny Devil is unmistakable - in fact it lacks close relatives anywhere. Though strongly associated with red sand deserts, it also inhabits scrublands and sparsely wooded areas right across the arid interior of Australia. It is reasonably common, and can often be seen along the verges of sandy tracks.
Its bizarre appearance is matched by equally remarkable features of its unusual lifestyle. Even its actions are distinctive: it walks with a jerky, stiff-legged gait that resembles some sort of clockwork toy, and often with the tail curled stiffly over the back. Moreover, like a chameleon, the Thorny Devil can adjust its skin color to better match its surroundings. The grooves and troughs between its spines form a sort of irrigation network that serves to channel morning dew or rain to the corners of its mouth, thus obviating the need for drinking water.
One of the Thorny Devil's most notable features lies in its extraordinarily rigid diet: it feeds exclusively on a particular kind of small black ant (called Iridomyrmex), which forages in the open. Hunting food for the Thorny Devil seems anything but strenuous: when it finds a moving column of these ants, it simply straddles it and gobbles the ants up as they move by, at a rate of about 40 per minute.
Gonnas and other reptiles
Related to skinks and similar reptiles, goannas are in many ways a sort of dry land counterpart of the crocodile in that they are able to use sharp claws, formidable jaws and a powerful lashing tail to subdue a wide range of prey. Largest of all Australian species is the Perentie. which inhabits arid parts of central and western Australia. It may reach 15 kg in weight and 2.5 m in length. The related Lace Monitor has a much wider distribution than the Perentie, being found more or less across the continent. With not much to choose in size between them, the Shingleback and the Common Bluetongue rank among the largest of all skinks. They are closely related and both are abundant and widespread. Both live on the ground, finding shelter in leaf litter, crevices and cavities in fallen timber. Most reptiles have small, smooth scales hut the Shingleback is instantly recognizable by its unusually big and knobbly scales.
Frogs tend to have a bad press - or, perhaps worse, virtually no press at all. But they are notable for the extraordinary diversity of their life histories (especially the reproductive cycle) and many are as attractive as any bird or mammal, in their own inimitable fashion. Many species are also gravely threatened. Several rainforest species once common in the eastern highlands, for example, seem to have vanished entirely through the 1980s, and have not been found since despite numerous thorough searches. This ‘mysterious vanishing’ also affected frogs of highland rainforests elsewhere in the world, especially in central America and West Africa over the same period. Causes remain obscure and much debated: global warming may be implicated indirectly but some researchers suspect a virus in the case of at least one Australian frog extinction. Others are endangered for very different reasons. The Green and Gold Bell Frog, for example, seems threatened mainly by urban sprawl throughout south-eastern Australia. Its distribution coincides very closely with the increasingly urbanized coastal belt between Brisbane and Melbourne. One colony was recently discovered on the site of the Olympic Games sports complex under construction at Homebush Bay, Sydney. It is not especially elusive. yet surprisingly little is known of its life history. Much the same thing might be said of several other species with broadly similar distribution and habits, such as Tyler's Treefrog.
Some others, while clearly declining, seem better able to cope with the varied challenges presented by life in the 1990s. The small Brown Treefrog, for instance, is probably the most familiar frog to the average suburban householder in south-eastern Australia. Occurring roughly from Sydney to Adelaide and widespread in Tasmania, it is common in gardens and frequently selects water tanks, ornamental fishponds and similar sites in which to breed.
Perhaps the best known of all native frogs is the Green Treefrog. Big, abundant, and easy to find, this charismatic frog has the most extensive distribution and perhaps the widest habitat tolerance of any Aus1ralian amphibian. It occurs wherever it can find damp and shelter from the vicinity of Sydney north to Cape York and right across the northern half of the continent around to Port Hedland in the west It is of1en found in cis1erns, outdoor 1oilets, laundries. and similar damp places around human habitations. Almost twice the size of other native frogs, adults may exceed 11 cm in total length. Even the tadpoles are giants of their kind, reaching about 4.5 cm in length just before they shed their tails and gills and turn into adult frogs. Green Treefrogs feed mainly on large insects and spiders, but they are easily big enough to swallow the occasional small mammal or bird that might happen to stray within reach.