The New Nature Page 17
The acclimatisers also liked plants. Their champion botanist was the redoubtable Baron Ferdinand von Mueller. In a long and ponderous speech to Melbourne’s Industrial Museum in 1870, he proposed that hundreds of exotic trees be established in Victoria’s forests, including red cedar and silky oak from New South Wales and Queensland and jarrah from the west. Von Mueller thought silky oaks – rainforest trees – would like Victoria’s deserts. In another talk he opined that ‘the explorers of the interior, by strewing a few seeds of Acacia lophantha, Casuarina quadrivalvis or some eucalypts near their camping grounds, might yet more permanently indicate these bivouacs than even by burning or cutting letters in many trees’. Ernest Giles must have received this advice. Exploring west of Uluru (Ayers Rock) in 1872 he reached an oasis where, his journal records: ‘I sowed a quantity of vegetable seeds here, also some seeds of the Tasmanian blue gum, some wattles and clover, rye and prairie grass’.
The acclimatisers lost sway by the turn of the century. The next push to move species around came from agriculture officers dabbling in the new science of biocontrol, and from conservationists worried about extinctions (see chapter 13). Biological control in its early days was a reckless affair, with none of the forethought practised today. Insects that ate crop-infesting aphids and scales were moved about willy-nilly. Before the advent of air travel they could seldom be brought from abroad, and many were traded between states instead. In the period 1895–1902 the traffic between Perth and the eastern states was complex. Ladybirds were going east and west (and also south to Tasmania). Some of the insects taken west turned out to be already living there. Some were never identified. No testing was ever done beforehand. Most introductions failed, either because the climates didn’t match or because the insects were too few. One report mentions ‘small parcels’ of Western Australian ladybirds being distributed over the colony of Victoria; this isn’t the way to establish insects.
But some species did take, including three ladybirds in the west that now benefit citrus and vegetable farmers (although they may be harming native insects in forests).1 The same ladybirds were sent abroad to tackle foreign pests, which they did with resounding success in India, South Africa, Egypt, New Zealand, Canada (where they live in greenhouses), and many places in between.
A dismal attempt at biocontrol was made on Lord Howe Island. In 1918 the captain of the Makambo suffered a blackout and his ship hit a rock, bursting its hull. The vessel was run aground for repairs and some black rats slipped ashore. They soon ruined the island ecology. Five of the eleven rainforest birds vanished for good, rats devouring their eggs and chicks. Birdwatcher Alan McCulloch, visiting in 1921, was appalled by what he saw – or did not see:
But two short years ago the forests of Lord Howe Island were joyous with the notes of myriads of birds, large and small and of many kinds . . . To-day, however, the ravages of rats, the worst enemy of mankind, which have been accidentally introduced, have made the note of a bird rare, and the sight of one, save the strong-billed Magpie and the Kingfisher (Halcyon), even rarer. Within two years, this paradise of birds has become a wilderness, and the quietness of death reigns where all was melody.
Lord Howe’s board of control was alarmed by rats attacking native kentia palm seeds, the island’s main export (grown worldwide as indoor pot plants). It hatched a risky plan to saturate the island with rat-eating owls. From Kempsey were fetched eight barn owls; from San Diego Zoo another ten (American) barn owls; and Tasmania provided almost a hundred masked owls. The barn owls did not last long, but the larger masked owls soon cast a dark pall over the island. Formidable predators, they struck at night with unerring talons, killing white terns, woodhens, black-winged petrels and the downy young of providence petrels. None of these birds had been bothered by the rats. To this day the owls inflict a heavy toll on white terns – exquisite snowy birds with doleful eyes that build nests on exposed limbs.
But the flightless Lord Howe woodhens, already threatened by pigs and pets, had most to lose, and the owls nearly caused their demise. By 1979 only thirty-seven remained, clinging to the crowns of two peaks. Their numbers have risen under careful stewardship because owls are now shot; today there are 200. But the Lord Howe boobook – a variant of Australia’s well-known boobook – vanished completely, its doleful call last ringing out in the 1950s. Another loser was a little bat. A tiny skull found in a cave in 1972 is all that remains of Nyctophilus howensis. Were rats and owls its nemesis? Probably. Rats remain a problem on Lord Howe today.
There is more to this story. When the forest birds vanished, the kentia palms came under attack from weevils. The board saw an ‘urgent need for more insectivorous birds’, and brought in silvereyes and sixty-eight Norfolk Island grey-headed blackbirds. The blackbirds soon died out – and went extinct on Norfolk Island too. Ironically, their demise on Norfolk was attributed largely to black rats. But ten magpie-larks (peewees) brought over to Lord Howe from Taronga Zoo in 1924 liked the island life, and their descendants now patrol fields and even venture indoors after food. But they are not forest-dwelling birds and probably did nothing to help the ailing palms.
Islands often became targets for foolish introductions. Brushtail possums placed on the Keppel Islands off the central coast of Queensland a century ago – apparently by fur traders – now strip bare the trees. Tammar wallabies placed on Greenly Island in South Australia in 1907 as food for shipwrecked sailors ruined it, turning shrubland into bare grassland. Koalas went to islands in Victoria (a fateful move discussed in chapter 18) and Queensland (Brampton, Magnetic, Newry, St Bees). Farmers freed goannas (Varanus gouldii, V. rosenbergi) on South Australian islands to prey on snakes, creating conservation headaches for today.
Oddest of all, in 1930 a travelling showman released eighty tiger snakes (Notechus scutatus) on Carnac Island, Western Australia, after his wife was killed by one. Tiger snakes live mainly on frogs, but the ‘tigers’ on this frog-free island eat lizards, introduced mice and an occasional seagull. Many are blind, their eyes pecked out by ropeable gulls. Farther afield George Clunies-Ross, ruler of the Cocos-Keeling Islands (now part of Australia), embellished his private island, Pulo Luar, by freeing Christmas Island imperial pigeons, Christmas Island white-eyes and island thrushes. White-eyes remain there today. Such meddling has continued in recent times, with grey kangaroos taken to Brampton, Whitsunday and Lindeman islands, and agile wallabies to Hamilton and Hook Islands (all in Queensland) to amuse tourists. These islands, most of them national parks, are now mired in marsupial problems, stroppy kangaroos sometimes striking tourists. Rottnest Island, off Perth, was lucky to escape an extreme fate. A bird society in 1960 wanted koalas and ‘dozens of rare and colourful birds’ freed to create a ‘naturalist’s paradise’. The government scotched this plan, but even so, budgerigars, cockatiels and rainbow lorikeets were soon to be seen winging around the island, although they did not survive for long.
The pet trade has also created many feral populations. In Tasmania naturalist Ronald Gunn noted in 1851 that ‘considerable numbers of the flying squirrel were, from their beauty, brought over as pets by the early visitors’. He was talking about sugar gliders, which resemble squirrels. After being taken to Launceston from Melbourne, they ‘escaped from confinement almost immediately after arrival; and it would now appear that they at once found food and shelter in the woods adjoining the town’. John Gould reported in his day that sugar gliders did not occupy Tasmania, but they are now widespread there. One escaped from me once, and I can well imagine these beguiling pets scampering up chimneys and squeezing out of boxes with ill-fitting lids, then finding each other by yapping at night.
Australians took a liking to birds as pets a long time ago. Traveller Peter Cunningham mused in 1827: ‘you soon become aware you are in a country very different from England by the number of parrots and other birds of strange note and plumage which you observe hanging on so many doors, and cagefuls of which you see exposed for sale as you proceed’. A variety of parrots and other b
irds have escaped over the years, or been freed around towns to add cheer. Gould saw ‘draymen and stock-keepers’ taking galah youngsters to Sydney for sale in England. ‘I have seen it as tame as the ordinary denizen of the farm-yard,’ Gould wrote of this parrot, ‘enjoying perfect liberty, and coming round the door to receive food in company with the pigeons and poultry, amongst which it mingled on terms of intimate friendship.’ Taronga Park Zoo released galahs in 1920 and crested pigeons somewhat later. Western Australia has feral cockatoos that date back to 1935. All of our big cities now carry flocks of feral parrots, the spawn of escapees and deliberate releases. Sydney boasts little corellas, pale-headed rosellas and ringneck parrots; Melbourne has scaly-breasted lorikeets and ringnecks. Brisbane’s long-billed and little corellas wheel about in flocks a hundred strong. Perth has the widest selection, with rainbow lorikeets, long-billed and little corellas, and, farther afield, sulphur-crested cockatoos and red-browed finches.
Long-billed corellas – bold white parrots – have done exceedingly well. Originally found in a triangle of terrain bounded by Melbourne, Adelaide and southern New South Wales, they fed upon the taproots of a dandelion-like plant called murnong. When millions of murnong-eating sheep and rabbits invaded their domain, accompanied by settlers wielding axes and fire, their numbers dived. They rebounded by attacking crops and weeds, and turned into serious pests. To dent their numbers, thousands were trapped and sold widely as cage birds. But the corellas proved so unruly that many pet-owners freed them, and feral flocks now wheel about loudly in Tasmania, northern New South Wales, the Gold Coast, Brisbane, Rockhampton, inland Queensland, north Queensland and Perth. Some of these populations will surely link up one day. The pet trade thus propelled a crop pest across a continent. Corellas today have a penchant for wheat, oats, rice, barley and sunflowers, although they also keep down certain weeds. They no longer eat much murnong, which has become scarce.
Perth’s loudest birds, to be heard screeching from date palms in the city centre, are feral rainbow lorikeets. Their numbers have grown since they were first noted in 1968. In his 1997 article ‘Rainbow lorikeets: an avian weed in the west’ David Lamont posited a population of one or two thousand spread across 30 kilometres. They squabble over the nectar of street trees, preferring eucalypts from interstate. Native birds are robbed of food and nest holes. ‘On several occasions they were observed dragging Australian ringneck nestlings from nest hollows and savaging them before dropping them to the ground,’ David noted. Orchard crops are at risk. The parrot problem already costs growers in Western Australia more than $1 million some years. When I told agriculture officers about a rainbow lorikeet I had seen flying wild around Bunbury, south of Perth, in October 2001, they went out and shot it the very next day. Sulphur-crested cockatoos east of Perth are also seen as a problem, and hundreds are shot, trapped and poisoned to stop them ravaging crops and displacing other parrots. Like the rainbow lorikeets, they belong in northern and eastern Australia, and Perth is a long way from home.
It’s hard to say how big a problem aviary birds pose. Are the ringneck parrots flitting around our cities breeding, or are they just bewildered strays? Red-browed finches from eastern Australia now flock about valleys near Perth, but by feeding mainly on weed seeds they stay out of trouble. But most escapees are parrots, and the tree hollows they breed in are needed by other birds. Hollows are now scarce around our cities.
Freshwater turtles kept as pets in open ponds readily escape, and owners often free them deliberately. Ponds in Sydney’s Centennial Parklands are crowded with ex-pets from Queensland and the Outback. There are northern snapping turtles (Elseya dentata), broad-shelled turtles (Chelodina expansa) and vulnerable Mary River turtles (Elusor macrurus), although whether they are breeding remains a moot point. Streams around Sydney also carry Brisbane River short-necked turtles (Emydura signata) and sawshell turtles (Elseya latisternum), and the Hacking River boasts a recently discovered subspecies of Murray turtle (Emydura macquarii) – which some experts suggest is an import. Murray turtles weren’t known in Sydney until recently, and this distinctive form may well have come from somewhere else, where it remains unknown. Sydney even has a few American turtles (Chrysemys scripta) in her waters, making eight species all told, compared to just one a hundred years ago (the common long-neck). Turtles and more turtles. Further south, all the turtles in Melbourne’s Yarra are introduced. John Coventry remembers thousands of common long-necks, netted in the Gippsland Lakes, selling in the Melbourne markets 30–35 years ago. The Yarra is now home to introduced Murray turtles as well, and Tasmania, previously turtle-free, now has feral long-necks (Chelodina longicollis).
In Melbourne water dragons (Physignathus lesueurii) from well to the east were set free by someone along the Yarra, and these hefty lizards, growing half a metre long, now live in Fairfield and Kew. At Eucla, on the Nullarbor Plain, frogs from the far west (Limnodynastes dorsalis and Litoria cyclorhyncha) now occupy ponds at a roadhouse. (The Nullarbor has no native frogs.) In the 1980s Gary Sankowsky, the owner of a butterfly farm on Mt Tambourine, tried to establish ulysses blues (Papilio ulysses) from north Queensland in the wild, but cold winters defeated him.
Wildlife sanctuaries are also agents of spread. In 1939 David Fleay freed six brush-turkeys in the grounds of Healesville Sanctuary, although these big birds don’t belong in Victoria at all. By 1946 they had ‘taken a firm hold in the locality’, although they later died out, probably taken by foxes. But turkeys won their freedom again in the 1980s when young birds escaped through the doors of a walk-through aviary. When a turkey mound appeared several kilometres away, raising local concerns, the birds were trapped. In Belair National Park, behind Adelaide, a small fauna enclosure was dismantled in 1972 and various occupants were freed. Several half-tame kangaroos died on the roads that year, but ten or so red kangaroos set up home around a golf course, and their descendants live there today. They are Outback animals with no taste for thick forest, and the mown lawns furnish the only suitable habitat. Koalas and emus won their freedom here too, the two emus recently bearing six young. In their dung they spread the seeds of African boneseed, a major weed.
To restore ecological stability Tim Flannery wants Tasmanian devils returned to the mainland, where they roamed until a few thousand years ago, but this idea entails risks. Devils could wreak havoc on native animals rendered rare by recent events. For nature in Australia there can be no return to the past. All too often relocations bring tribulations, even when conservation is the motivation. The next chapter recounts some embarrassing – and devastating – examples of this.
1 The three ladybirds were Cryptolaemus mountrouzieri, Halmus chalybeus and Harmonia conformis.
‘We wish to so order our civilisation that every species of plant and animal indigenous to the continent is preserved in such circumstances that they may live their natural lives and reproduce their kind.’
Sir James Barrett, Save Australia (1925)
Armed with axes, matches and guns, aided by foxes and rabbits, Australia’s pioneers exacted a dreadful toll on wildlife. Naturalists a century ago feared little would survive. The new idea of the national park seemed to offer the best hope. But national parks had to be secured against foxes, which were viewed as especially destructive. Islands appeared to offer the best prospects. The first sanctuaries were not set up to conserve ecosystems (an idea for a later era), but as safe receptacles into which animals could be deposited. This idea drew more from tales of Noah’s Ark than from any grasp of biology. Animals from hundreds and sometimes thousands of miles away were thrown together onto islands of forest, usually to die quick deaths.
It happened first on Wilsons Promontory. Three naturalists trekking there in 1884 were awed by ‘this noble granite Promontory, the Cornwall of Victoria’. When, three years later, plans were hatched to settle a thousand Skye crofters there, alarmed naturalists and biologists ran one of Australia’s first ever conservation campaigns, eventually – after the usual false promises fro
m politicians – securing the land as a national park. But the ‘Prom’ was not saved for its animals; it was thought not to have many. ‘We saw nothing and could hear nothing of the Kangaroo, Lyre-bird, or Platypus’, naturalist A.D. Hardy admitted in 1906. The park’s real value was its scenic splendour and strategic design – a promontory linked to the mainland by a mere wisp of isthmus. Like Tasmania’s Port Arthur, it could be walled off to protect the animal inmates that would come later. Hardy explained how:
First would necessarily come the poisoning of the wild dogs and the erection of a dog, fox, and rabbit proof fence across the isthmus. The introduction of kangaroos, emus, other species of wallabies than exist at present, and smaller marsupials would follow. Lyre-birds from Gippsland could be transferred to the gullies of the eastern side at Sealer’s Cove, Refuge Cove, etc., and at Roaring Meg Creek in the south, while the Platypus could be acclimatized in many of the streams. There is in all about 10,000 acres of good and poor grazing land, which would suit kangaroos and emus in parts and wallabies throughout . . .
There are many kangaroos, wallabies, and a few emus on Snake or Latrobe Island, which could be conveniently transferred to the Park, while from many parts of the State could be procured native fauna suitable for the populating of this large area. The trustees and directors of the various State Zoological Gardens will doubtless assist in providing such native animals as they have in captivity but are now scarce or hard to procure. In many cases the security and peace of the Park will result in over-breeding, but the surplus could be easily disposed of in the re-stocking of zoological gardens, etc.