by Tim Flannery
Since there appears to be no intrinsic bar to meat-eating marsupials, perhaps the environment holds a clue to Meganesia’s paucity of large carnivorous mammals. Meat eaters sit at the apex of a broad-based food pyramid and are thus the most vulnerable of life forms to disturbances in the food chain. An area of grassland that supports billions of individual grasses, for example, may sustain only a few thousand large herbivores. These, in turn, may be able to support fewer than one hundred large carnivores. If the environment is poor, large herbivores will be rare and thinly spread, and a critical point may be reached where the density of prey is so low that a population of large meat eaters cannot be sustained. If further impoverished, such an environment can no longer support any large carnivores.
Australia is notoriously infertile. An old continent with a stable geological history, it has experienced no widespread glaciation, mountain building or volcanic activity—the forces that create new soil—over the past 50 million years. As a result of its quiet past, Australia is a land of old, thin and leached soils. In the country’s semi-arid zone, soils have about half the levels of nitrates and phosphates of equivalent soils elsewhere. The amount and quality of arable land is another good measure of productivity, and even the ten per cent of Australia’s total land that is considered arable is marginal when compared with other landmasses. Other indications of poor soil come from Australia’s plants, which have developed a variety of strategies, including slow average growth rates, to cope with the lack of nutrients.
A contributing environmental factor is El Niño, or the Southern Oscillation cycle, which influences rainfall with a periodicity of roughly a decade. In some years, Australia receives high levels of rainfall, and productivity peaks, as it did in 1990. But in El Niño years, such as 1992, rainfall is reduced and prolonged droughts are likely. On no other continent does the cycle have such an extreme impact. Its effects can readily be seen in the high degree of nomadism and non-seasonal breeding in many Australian animals, particularly birds. When such variability is superimposed on a system that is already marked by low productivity, top-order carnivores are subject to exceptional stress.
These climatic factors have so shaped the biology of the region that even areas of rainforest lack big carnivores. The largest area of rainforest in Meganesia is in New Guinea, which is even more noteworthy than Australia for its lack of meat-eating mammals. Here we have no evidence of indigenous large cat-like or scavenging predators. Before human settlement, New Guinea supported some two hundred species of rather small mammalian herbivores and insectivores, but was home to just one large warm-blooded carnivore, the thylacine. Today, apart from humans, the largest predator is the bronze quoll, a one-kilogram, civet-like species.
If large meat-eating mammals are disadvantaged in such an ecosystem, might animals that require less food and energy fare better? Reptiles eat far less than mammals do, having no need to create inner body heat. They can survive long periods of food shortage and can exist at higher population densities than mammals, relative to their prey. Cold-bloodedness thus becomes a great boon to survival. I believe this is what has happened in Meganesia, home to a remarkable array of carnivorous reptiles. Before the arrival of humans, the largest carnivores in the region were Wonambi, a fifty-kilogram python-like snake with a thirty-centimetre girth; a giant land crocodile known as Quinkana; and a goanna—a kind of monitor lizard—called Megalania. Weighing as much as a tonne, and more than six metres long, Megalania would have dwarfed present-day reptiles. Its nearest living relative is the Komodo dragon, which survives on a few small Indonesian islands adjacent to Australia. Although it weighs only a fraction as much as Megalania, the Komodo dragon is capable of killing goats, calves and even humans. Megalania would have been powerful enough to subdue diprotodons, the rhino-sized marsupial plant-eaters that were the largest of all Australian mammals. Wonambi, the snake, occupied a far different ecological niche. It lived much further south than large snakes do today and its remains are often found in rocks and caves. Its head was large and its jaws were filled with hundreds of tiny teeth. It may have fed upon wombat- and wallaby-sized mammals. The least known of these reptiles is the three-metre long, 230-kilogram crocodile, Quinkana. It seems to have been quite independent of water, for its fossils have been found in caves that contain only remains of terrestrial species. Quinkana had a large, box-like snout and compressed, serrated teeth. It may have competed with young Megalania for the now-extinct kangaroos and smaller diprotodons.
Are the climatic patterns of the Pleistocene and more recent times an aberration in the history of Meganesia? Palaeontological research suggests that during much of the ‘age of mammals’, and certainly since about 20 million years ago, Meganesia has been relatively resource poor and lacking mammalian carnivores. On the other end of the spectrum, leading into historic times, Meganesia has been colonised by humans and, more recently, by animals introduced by them. How have the predators among them fared? The number of humans in Meganesia since people first crossed the sea from Asia some 40,000 years ago remained small prior to European settlement.
Adaptable and omnivorous, humans also became the top-order predators; their hunting prowess probably led to the extinction of all terrestrial vertebrate species that exceeded them in size, including all land carnivores larger than the thylacine. The dog known as the dingo, introduced some 3500 years ago, apparently drove both the thylacine and Tasmanian devil to extinction on the mainland. The success of other smaller, introduced predators such as the fox has been detrimental to native predators such as quolls.
Humans, dingoes and foxes have not caused a net increase in the number of mammalian carnivores in Meganesia; they have simply replaced the few existing warm-blooded carnivore species. But today, Australia, Tasmania and New Guinea can still boast a rich supply of reptiles—ten species of goannas and a further ten species of pythons that weigh at least 4.5 kilograms. This remains a record number of sizable cold-blooded carnivores.
The case of the Meganesian meat eaters opens up new areas for exploration while reinforcing the view that because of its unusual climatic conditions and long isolation, Meganesia is truly a separate experiment in evolution.
Men of the Forest
1996
THE WORLDS OF tree kangaroos and men are largely separate. The lives of men centre upon villages, gardens and rivers, and upon the gentler and more easily hunted closer slopes of the mountain ranges. The world of tree kangaroos is often perched high above. It is one of precipices and swirling mists—a cold, dank and dangerous world. The infrequent flashing moments when tree kangaroos and men meet, however, are full of meaning and excitement. Their importance is out of all proportion to their brief duration, for they shape the lives of both the hunter and the hunted long after they have passed.
In New Guinea, the man who has successfully hunted a tree kangaroo has greatness bestowed upon him. He has conquered the largest, most prestigious and human-like marsupial known to his people. In sharing its meat he wins brides and cements alliances. In wearing its skin, in warfare or on grand occasions, he reminds all present of his prestige. Thus the successful hunter of tree kangaroos has status, and often many children. People listen to him: the knowledge a hunter gains during those precious few moments when he sees a tree kangaroo face to face are recounted over and over to an eager audience. And in the mind of the hunter they are added to the retold experiences of father, uncles and grandfathers. The knowledge of many coalesces to form a detailed understanding of the lives of these most obscure animals.
For tree kangaroos, too, the moment of encounter with a hunter is a crucial one. Those that tarry too long, not realising the danger they are in, meet a swift death. Likewise, those whose belly is a little too pale and easily seen in the canopy from below, or those that are careless in choosing their daytime roost, will pass on no more genes. This has happened over 20,000 tree kangaroo generations, as human hunters have pursued their prey. Throughout this time tree kangaroos have also stored up knowledge,
not in memory but in genes. Those with the right behaviours and colours have survived to pass on their traits. A tree kangaroo’s behaviour, and even its appearance, if read properly, presents a catalogue of its predator’s behaviour as detailed as the predator’s is of the tree kangaroo as prey.
I have hunted tree kangaroos in two ways: by accompanying New Guineans who have searched for tree kangaroos using traditional methods, and by tracking tree kangaroos with radio-tracking devices. Even so, my firsthand experience of wild tree kangaroos is limited, and much of what I know has been learned from consummate hunters whose knowledge encapsulates the experience of many lifetimes.
HUNTING WITH SKILL AND MAGIC
In February 1984 I was lying sick in a rough hunting shelter high in the Victor Emmanuel Range of far western Papua New Guinea. I had just spent four weeks in the lowlands near the Irian Jaya border hoping to learn something of tree kangaroos. I found to my chagrin that I was at too low an elevation, and rather than return home empty-handed, I decided to devote my last two weeks to working with Telefol hunters high in the Victor Emmanuel Range.
At Telefomin I met Dan Jorgenson, an anthropologist who had spent many months among the Telefol. He directed me to two experienced older hunters, Tinamnok and Amunsep. Tinamnok was in his forties and a superb hunter. Even he, however, professed no skill in hunting D’bol, as the Telefol know Seri’s tree kangaroo (Dendrolagus dorianus stellarum). To do that I would need to consult Amunsep, and he was up-country. Dismayed, I decided to accompany Tinamnok into the high country on the Sol River, a day’s walk away.
Almost as soon as I arrived at the little lean-to Tinamnok used as a shelter when he was hunting, I fell ill. At Yapsiei I had contracted what I now know was giardia and had been laid low for days. Its return on the Sol River left me helpless. Tinamnok would go out hunting for two or three days at a time, sleeping in hollow trees or napping on a sunny riverbank by day, finally to return with his booty. It took all my strength just to weigh, measure and skin the specimens he brought to me. One night, after about a week’s work, a dog walked casually into camp. Presently, another, then another followed it. Some minutes later a man arrived. Amunsep was in his fifties. He had a broad face with a typically large Melanesian nose and frizzy hair that was greying at the temples. Over one eye was a boil the size of a hen’s egg. He wore ex-army shorts and a beret, but had doubtless spent his early years dressed in kamen and autil, the traditional Telefol penis gourd and cane waistband. Over his shoulder he wore an exquisite string bag or billum, made with care and an eye to utility that only Telefol women possess. It was decorated like no other, for the tail tips of at least twenty D’bol adorned its outer surface. Around Amunsep’s neck hung a miniature billum even more beautiful than the first. This looked impossibly small to be of any practical use.
Doubtless Amunsep was surprised to find someone at the camp. Perhaps he thought me too lazy or incompetent to follow Tinamnok. Whatever the case, I found it difficult to disabuse him of his opinions, for Amunsep was a traditional man who spoke neither English nor Pidgin.
It took time for him to respond to me, but one evening, nearly a week after first meeting, I greeted him with the customary phrase ‘Ngum saro’, which he returned before sitting by the fire. After an awkward silence I fished out of the ashes a cooked sweet potato (our principal food) and passed it to him. Then, as he ate, I began to read aloud the list of Telefol animal names given to me by Tinamnok.
With each name correctly pronounced, Amunsep would mime the animal’s behaviour, give its call and indicate, by pointing, its habitat. There was Bogol, as the Telefol know the New Guinea harpy eagle (Harpyopsis novaeguineae). So powerful is this bird that it is reputed to carry off young D’bol, and even human infants neglected momentarily by their mothers. Its call, like the release of a tense bowstring, is followed by the low clucking call of its mate. Amunsep imitated it perfectly. The mimed terror of its descending talons and the fierceness of its eye had my heart in my throat.
Finally, I came to D’bol. Instantly, Amunsep made the animal come to life for me. Its immensely powerful forearms, its fearfully sharp claws, its imperious stare as it looks down at its assailants from high in the canopy—all were conjured up. The snuffling sounds and grinding of teeth signifying annoyance were there, as was its peculiar posture and hop. It was nearly 2 am when the performance finished. I looked up at the starry night, which promised good hunting on the morrow.
I was woken, not by the first grey strands of dawn, but by acrid smoke. Amunsep was already up, kindling the fire for warmth. As I watched from my wet sleeping bag, feeling sicker than ever, Amunsep took the tiny billum from around his neck. From it he extracted what appeared to be some native tobacco. He rolled it into a tiny cigar, lit it and inhaled deeply. Grabbing the nearest dog by the foreleg, he roused it from slumber by blowing smoke into its nose. The whimpering animal was released and the process repeated on the others. Next, Amunsep took the pale, scented bark of a plant known to Telefol as tabap kal. This he chewed until it was pulp. Again he took up the dogs and blew the white fragments into each one’s face. Finally, he took from the billum a pebble of beautiful deep-red agate, rolled smooth and pellet-like by a stream. This stone, called nuk terap, he rubbed gently on each dog’s forehead, all the while chanting under his breath. Then Amunsep was gone and I was left alone in the forest for another two days.
On the third afternoon Amunsep and Tinamnok returned to camp. They had the usual kinds of cuscus, but D’bol had eluded them. At last I felt well enough to walk, and together we descended from the world of D’bol into the world of men.
It was to be another two years before I would meet D’bol face to face. Amunsep suffered a serious knee injury soon after our work on the Sol River and was never to hunt the rugged country again. And so I tried hunting with several other men.
One group of young men had a dog by the name of Rocket. Rocket was reputed to be a paragon among the canines. According to his owner, Rocket was such a diligent hunter that he was wont to go out by himself at night, secure a cuscus and carry it back to camp, placing it under his master’s head to act as a pillow, thus augmenting both slumber and breakfast. But while I was with him, Rocket proved to be a fizzer, for he did not aid in the capture of a single game animal. Instead, I suspected him of stealing rats from my traps.
Quite by surprise, one afternoon in April 1986 a group of young men came into my camp on the Sol River carrying a young male D’bol. It had probably been caught while travelling out of its natal area in a search for territory not already guarded by an adult male. Perhaps it had chosen some less rugged slope for its new home and had been spotted there by the hunters.
That evening the camp was alive with activity. I was busy measuring, taking samples and skinning. In the evening, our largest pot was filled with the meat of D’bol along with various greens picked from the surrounding vegetation. Late that night, the cooking finished, I was handed some meat. It was delicious, not as gamey as kangaroo, and as tender as could be wished. In my enjoyment of the meal I failed to notice that no one else was partaking. Early that morning the still-full pot was carried down into the village. I later learned that the meat of D’bol was considered such powerful food that only the most senior Telefol men could eat it. It seemed that no one in my camp was eminent enough to partake, but as an honoured guest and a Tablasep (white man), I was exempted.
RADIO-TRACKING
In 1985 I was conducting a faunal survey near Wigotei Village in the Torricelli Mountains of western Papua New Guinea when I fell sick with scrub typhus. This misfortune terminated my survey, but not before I had obtained the claw of a tree kangaroo.
The claw was the solitary neck ornament of one of my stretcher-bearers, a local village man who helped carry me to a mission station to receive medical treatment. Travelling through the bush in an uncharacteristically horizontal manner, my eyes (when I could force them open) would light upon many strange things, some real, others undoubtedly imagined. But my gaz
e kept returning to the object gently swaying from a string around the neck of the man beside me. At the end of our peculiar journey, I summoned the presence of mind to purchase it from him. When I returned to the Australian Museum in Sydney some weeks later, I examined the claw and found that it was unlike that of any known species.
It was to be three years before I could return to the Torricelli Mountains, but when I did in May 1988 I obtained a juvenile specimen of a black tree kangaroo. The Olo people called this animal Tenkile, meaning ‘I stand’ in their language. To a biologist, it was clearly a species new to science, one that had a very limited distribution. I obtained grant funds to return to the area to undertake research and a conservation program.
Conditions in the Torricellis are among the most difficult I have ever experienced for long-term field work. Before leaving Australia I had visited Roger Martin, a biologist undertaking a detailed study of Bennett’s tree kangaroo near Cooktown. Roger had lived for months in a waterless camp, which was little more than a tarpaulin stretched over some sticks. He had endured insects and abject, interminable isolation—with the exception of wandering cattle—before being able to place a radio collar on a tree kangaroo. Roger is clearly a tough bushman, yet when he visited the Torricellis, he found it almost unbearable.