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National Geographic: Australias Animal Mysteries (1999)
With the coming of each new dawn,
shadows of an ancient past echo across Australia land of eternal mystery. Alien and remote for countless centuries, it remains today an almost mystical land... a land only recently disturbed by the arrival of man. Long before the time of man, there appeared here creatures among the most bizarre on Earth. So unlike other animals are they that many early European explorers could hardly believe they were real. Even today, three centuries later, many of the questions the animals pose to science remain unanswered. Throughout Australia, investigators and scientists probe the secrets of this infinitely varied wildlife. Animals once dubbed "living fossils" have been properly identified and categorized, their evolutionary relationships better understood. Yet, inevitably, there remain more questions than answers haunting, ago-old mysteries that beckon all who behold the spectacle of life unique to Australian shores. Washed by the South Pacific on the east and the Indian Ocean on the west, Australia stretches for almost three million square miles. It is the world's smallest continent, the largest island a self-contained biological laboratory unique in the world. Science has long been puzzled by how and why this island-continent became home to what is probably the most distinctive assemblage of creatures found anywhere in the world. Part of the answer lies in Australia's remoteness, its geographic separation from the rest of the world. Cut off from the Earth's great landmasses, Australia has evolved in seabound isolation for some 50 million years, its wildlife relatively undisturbed by influences from the outside. But the world as we know it today does not hold all the answers to Australia's past. We must look to a distant time in the Earth's geological history when the continents were joined. Scientists believe that somewhere in the continents we know today as the Americas, Antarctica, and Australia, the earliest marsupials evolved and fanned out. When the landmass split apart, the continents carried their life-forms with them. However, in South America, predators and competitors for food eventually wiped out a great number of marsupial species. In Antarctica they became frozen out of existence. Only in Australia, safely cut off from competitors, could these unique creatures flourish. And until the relatively late arrival of man, they evolved, for the most part, undisturbed for millions of years. Even today, Australia's human population is only 141/2 million, and because much of the interior is a harsh, arid land, the large cosmopolitan centers cluster on the coasts. A common myth about "Down Under" is that one can see kangaroos hopping down the streets of Sydney. Yet it is quite likely that many of these people have never even seen one, and perhaps never will, outside a zoo. Zoos and sanctuaries are popular attractions throughout Australia. Here, tame animals provide the opportunity for an intimate look at some of the country's most treasured resources. Most of the kangaroos at this sanctuary have been raised here as orphans... their mothers the victims of automobiles or a hunter's gun. Under the watchful eye of a keeper, the joeys, as young kangaroos are called, can be cared for until old enough to be on their own in the park. I'm going to put him in a bag. A pillowcase is an ample substitute for the mother's pouch. Good joey. That's a baby. Sit square on. Put two hands one on top of the other. Perhaps number one of any popularity poll is Australia's pride and joy, the cuddlesome koala. ...Straight over your shoulder towards the camera. Chin up. And thank you. Okay miss, just watching me, please. Oh, you've got a beautiful smile, dimples and all. How about that, eh? Captured young, koalas come to accept humans. Even in the wild, they are basically unaggressive if undisturbed. Life for the wild koala revolves in and around forests of eucalyptus trees throughout eastern Australia. On the ground just to move from tree to tree, the koala spends almost all its time high in the branches. It has developed highly specialized adaptations for its arboreal life... long arms, well-padded paws, and opposable thumbs with a vice-like grip. Not only home and shelter, eucalyptus trees provide the koala with its primary food. It eats about two pounds of leaves a day. Despite superficial resemblance, the so-called koala "bear" is not a bear at all, but a true marsupial a pouched animal like the kangaroo. After birth the young will stay in the mother's pouch for about six months. When strong enough to leave the pouch, it will do so only intermittently, and for the next few months will travel everywhere with its mother, clinging either to her back or chest. The koala has inspired myriad reactions from observers over the centuries. One author has written: "The koala's expression always reminds me of a Byzantine Madonna or some dowager duchess... rather bored, well-fed and well-bred... But many aborigines saw something quite different to them the koala represented the reincarnation of the spirits of lost children. A research team from Queensland's National Parks and Wildlife Service is studying the koala's ecology and reproduction in the wild. Their study area is roughly 600 acres where 30 to 40 koalas normally live. He's got up higher than he was when we first saw him... Yeah. Okay, let's go. Led by Dr. Greg Gordon, the researchers have been capturing and tagging koalas since 1971. It is by no means a simple task. First they must get them down. And, as the wary animal climbs even higher, the pole must be extended to reach it. This is not going to be all that easy, Greg. He's got to he's going to drop just near the edge of the embankment. Yeah, I think you're right. Experience has taught the scientists that the procedure is basically safe the koala its sturdy build and thickly padded rump seem to protect it against the fall. That's it. You're just below him now. You're right below him. Go on, drive him off. Got him? See, doesn't hurt him at all. Particularly when they come down on a branch like that. It was a rude awakening, wasn't it. Though easygoing by nature, a koala may become aggressive under stress. The bag is a precaution against his powerful claws and tenacious bit. Sought for its fur in the early decades of this century, the slow-moving koala was hunted to the very brink of extinction. Today, thanks to government protection koalas are once again secure. Recently, however, it this area of Queensland, there has been a puzzling decline in the birth rate. By tagging the animals and studying them over a period of years, the scientists hope to pinpoint the cause. In the meantime, thorough examinations expand their understanding of growth patterns and general states of health. Color-coded tags make the animal easily identifiable even when high in the trees. This one was tagged originally when still in his mother's pouch, and much about him is already known. Tooth wear is about the most reliable indication of age. This male is roughly three years old. Now, we'll do his chest gland. On their chests all male koalas have a scent gland which exudes a distinctive odor. By rubbing the gland on tree trunks and branches, they announce their presence to others in the area. Okay, we'll go out of the sun, over here. That sound like a good idea. Okay, fellow. There we are. Good as new. He's not going to go to that tree again. Go on. ...nasty, that one... Momentarily disoriented after his release from the bag, the young koala seems unsure of what to do next. But within seconds he heads back quickly to the same tree from which he'd been captured. Guess he proved me wrong. He took that rather well. Sensing only that he is safely back where he wants to be, the koala cannot possibly realize how today's encounter with strangers may well help determine the future of his kind. Perhaps the very symbol of Australia, the kangaroo remains as fascinating today as when the first live specimen reached England in the 1700s. A handbill announcing the event proclaimed that "to enumerate its extraordinary Qualities would far exceed the common Limits of a Public Notice". Now, almost two centuries later, a rare piece of film documents one of the kangaroo's most extraordinary qualities of all. After a gestation period of about a month, this red kangaroo prepares to give birth. Though scientists now understand the biology of marsupial birth, it is no less remarkable to behold. All marsupials are born in an undeveloped state, their growth to be completed inside the pouch. Defenseless and blind, the tiny newborn, completely unaided by the mother, must navigate through her thick fur toward the pouch. If it loses its way, it will die. Once inside the pouch, guided only by its sense of smell, the newborn finds one of the mother's nipples. Here it will remain attached, suckling for more than six months. Now the joey will be strong enough to leave the pouch intermittently. But even when it is old enough to graze, it will return to the pouch to nurse for several months more. Amazing in their adaptability, some kangaroos are as at home in the trees as others are bounding across rocky slopes. There are about 50 species of kangaroos in Australia ranging from up to seven feet in height to the size of a common rat. But one trait they all share is that they hop. Though it may weigh as much as 200 pounds, the kangaroo is a picture of grace when it takes to flight. It can reach speed up to and cover as much as 25 feet in one leap. Recently scientists were amazed to discover that, at certain speeds, the kangaroo actually uses less oxygen the faster it goes. It was found that, like the spring in a pogo stick, the kangaroo's leg muscles and tendons store energy, which is then released without effort when the animal next pushes off. Though the kangaroo is no doubt the most famous marsupial, Australia boasts as many as The ferocious-looking Tasmanian Devil is one of the few that eat meat exclusively. Once can only imagine the astonishment of early explorers when they saw a pouched animal take to the air. These possums do not actually fly like birds, but their kite-like membrane enables them to glide for distances of 40 yards or more. Only in small patches of Western Australia will one find the numbat, a small, gentle marsupial now extinct in other parts of the country. With sharp claws the numbat roots out termites, its primary food. Its long, sinuous, sticky tongue can capture thousands of the insects a day. With its distinctive bands of white and its bottlebrush tail, the numbat is considered by many to be Australia's most beautifully marked marsupial. The majestic Blue Mountains lie Here, beneath the vivid blue haze which gave the mountains their name, areas of pristine wilderness abound. Nestled in the hills, an historic estate called Yengo spreads across 25 acres. For the past 12 years it has been a private reserve dedicated to breeding endangered animals. He's really heavy, I'll tell you that. The owner is businessman Peter Pigott, one of Australia's foremost conservationists. With his wife and son, he is transferring a wombat injured in a fight to a safer enclosure. Come here. Come on. Nice leg to bite. Pigott's breeding success with wombats is considered phenomenal better than any zoo and is attributed to his concern for creating the most natural setting possible in a captive environment. I guess that my first opportune at doing something very constructive in the field of conservation was the rediscovery of a wallaby that we thought was extinct. The parma wallaby, a mall kangaroo only about 14 inches tall, was abundant until early settlers destroyed its habitat and introduced new predators. Though thought to be extinct, a small colony was discovered in 1965. Starting with only 18 animals, Pigott has increased the population here to more than 200 in ten years. A lot of people say to me, now why should we conserve wildlife? Why should we be really concerned? I mean, aren't people more important than wildlife? We are all part of the 600 million years of evolution and I suppose that one of the great things that separates mankind from the animals is our sense and appreciation of the esthetics our love of literature, our love of art and poetry, and of nature itself. I often think that if we lose this we disregard the world that's around us and the animals that are here. We might wake up one morning and find ourselves on the endangered list. Her skies ablaze with color, Australia has been called "the foremost land of birds". More than 300 species are unique to her shores. One of Australia's most distinctive birds, the mallee fowl is a prodigious engineer. To incubate their eggs in a harsh environment that is generally dry and subject to sharp temperature changes, they build mounds up to 15 feet across and several feet high. Working together, male and female have laid down a bed of wet leaves and twigs. To seal in the moisture and heat of the fermenting compost, they cover the mound with sand. The egg chamber itself lies at the heart of the mound. Beginning in the spring and continuing for three to four months, the female will come about once a week to lay a single egg. The mallee regions are marked by sharp temperature fluctuations between day and night and as the seasons change, but the egg chamber must be kept at an almost constant 92 degrees. Once the female has laid her egg, she will heave the tending of the mound to her mate. To determine the temperature, he probes the sand. With a sensitive spot either in his bill or tongue, he gets a reading as accurate as any thermometer. Regulating the temperature by removing sand to release heat or adding sand to conserve it is an almost constant job for the bird, a consuming task to which he dedicates himself for up to nine months of the years. Roughly every two months, a chick will work its way up through the thick soil and wander off, never to see its parents again. From the depths of the forest echoes a haunting and memorable sound... the lyrebird, master of vocal mimicry. Seemingly endless in its variety, the lyrebird's repertoire include other bird calls, as well as man-made sounds. The mating ritual is highlighted by a shimmering display of the bird's immense fan-like tail. In central Australia, heavy rains have flooded to desert. But storms are few and short-lived in this harsh, arid country. As the claypans begin to dry up the water-holding frog demonstrates a remarkable adaptation. Increasing its body weight by as much as 50 percent with water absorbed through the skin, the frog burrows into the softened clay to a depth of more than three feet. Once underground, it will enter a sleep-like state its active life essentially over until the desert once again sees rain. Encased in a cocoon-like bag of dead skin, the frog will remain in its chamber, sealed beneath the now dry and hardened earth. In times of drought, these amazing creatures have been known to stay buried for two years or more. Only when the rains finally come and the earth begins to soften can the frog begin to emerge. It must mate quickly so that his young will mature in time to soak up their own water supply and bury themselves until the next rains come. In the forests of southeastern Queensland, a major scientific discovery was made in 1972. Since that time, a bizarre animal unique in the world has been making history. The first noteworthy fact was that it existed at all Australians had always believed that in their country there was no such thing as a frog that lived in water. Since the time of the original discovery, captured animals have been sent to the Zoology Department at the University of Adelaide for study by Michael Tyler. one of the countries foremost takes on ton-frog. Spending their daylight hours hidden under rocks these frogs are the most light sensitive and shy of any Tyler has ever seen. The only way he has been able to observe them successfully is to remove them from their regular aquarium. In a specially built tank with one-way glass windows, the frogs will be unaware of Tyler's presence. Because many have died in captivity and in recent years no more have been found in the wild, these two remain to unlock the mysteries of some of the most unusual animal behavior ever recorded. But though action like this free-falling is bizarre and unexplained, it is the animal's reproduction that has most electrified the world. What is so unusual about the gastric-brooding frog is the fact that it carries its young in its stomach. Superimposed on an X ray, an artist's conception follows the growth of some two dozen tadpoles until, at roughly eight weeks, the female's stomach is completely distended with fully developed frogs ready to be born. The mother opens her mouth and then she dilates her esophagus and the babies pop up from the stomach one or two at a time, and sit upon her tongue. And then they sit and look around, look at the world outside, and then just very, very gently step out. Tyler's rare photo of an actual birth has made headlines around the world. Here we have an animal which can switch off acid being produced in the stomach. An awareness that that would be an extremely novel way of being perhaps able to treat people who might need to be able to make use of that as an advantage. For an example, during the treatment for peptic ulcers, it would be so useful to be able to switch off gastric acid secretion totally for a period of time and do it very, very readily. I say it's a long, long way. between what we've done so far and such a thing as a possibility. But, I mean, in the matter of a few years ago no one would have dreamed that the existence of this frog with this habit could possibly occur and so, with that in mind, I don't think it's impossible or too far fetched to maintain hopes that is may have clinical application. In the reptile world, Australia stands out as the continent with the largest proportion of venomous snakes. The death adder is one of the country's most poisonous snakes. Without treatment, half of its human victims will die. Like all snake, the death adder feeds primarily on small animals like lizards. Its approach is neither timid nor aggressive, for in the end it relies on an extraordinary device for enticing the skink within range. Wriggling its tail tip as a lure, the snake can lie quietly and wait. Attracted by what must appear to be a squirming insect, the skink draws near. The venom, five times more powerful than that of its cousin, the king cobra, paralyzes the muscles that control breathing, and the victim dies of asphyxiation. The Australian reptile Park was founded by Eric Worrell, who has worked with snakes for more than 50 years. People overseas always think of Australian animals as being koalas or kangaroos. They don't think very much about our snakes, our other reptiles. We have the deadliest reptiles in the world. Robyn Worrell is an experienced snake handler. With careful concentration combined with skill, she has been bitten only once in ten years. Though her snake-milking demonstration may draw curious crowds, the primary goal of her work lies in the realm of science and medicine. What I'm milking here is the mainland tiger snake. There's probably about seven or eight different types of tiger snakes in Australia. It's the third deadliest that we have in Australia. What I'm actually doing now is just enticing the snake to bit over the rubber. The fangs are penetrating through that rubber and the venom accumulates in the bottom of the beaker. Generally we keep... Over the years, the venoms collected at the park have proved invaluable to laboratories developing snake-bite cures. The work we do here is vital in that it has been estimated that we save one life a day from snake bite. That's during the snakes' active season, which is to say from September until April. And I think that works out to something around 20,000 lives that this organization has saved since we started. Thanks largely to the Worrells' work, there are now antivenoms for all Australia's poisonous snakes. In addition to snakes, Australia's reptiles include some Lacking venom as protection against predators, they depend on an impressive array of defenses and bluff. Looking like some creature from the Dinosaur Age, the Thorny Devil belongs to the group aptly called dragon lizards. Actually a squat, slow-moving, ant-eating lizard, the devil is found throughout the arid regions of central and western Australia, and has adapted to some of the continent's harshest conditions. But perhaps its most notable adaptation is its coat of spines a barricade of daggers warning all the might come near. Lizards abound throughout Australia. The most famous and perhaps the most spectacular roams the forests of the warmer northern regions. Undisturbed, the frilled lizard looks harmless enough. But in the face of an enemy, it performs with remarkable bluff. If all else fails, it need only make a hasty retreat. The entire range of Australian wildlife is the domain of these two naturalists Together they are known as Mantis Wildlife Films. Individually they are Australian Jim Frazier and his British-born partner Densey Clyne. For the past 12 years they have specialized in filming behaviors the naked eye can barely see. Today the object of their search is one of the most fearsome ants on earth. Yes. They're coming out already. This one is bringing something into the nest. What is it? It looks like a bit of food... Food or... Debris. I don't know what it is. About an inch long, They've seen us already. the formidable bulldog ant inflicts a powerful and painful sting. But to film their behavior, Jim and Densey must collect the entire colony perhaps as many as 400 ants. Even the larvae be taken, but Jim's film sequence to be completed. There we are. At Densey's home, the headquarters of Mantis films, Jim has built a plaster model based on his knowledge of the nest in the wild. There's quite a lot of them on the glass there... Yes, right. They're coming out everywhere. The slippery white coating at the top will prevent the ants from escaping. It's amazing what a lot of noise they make, isn't it? Yeah. Running around. You can actually see the sting coming out and trying to sting the glass. Going in between the sections of glass. Look at this one here. Look at the sting. They're not happy are they? Well, if I had my home uprooted like that, I wouldn't be very happy either. Jim, I think although they're in a bit of a panic now, you know, as soon as the queen is settled in one of the chambers, they'll be alright. Yes. They're starting to slow down now. They're not quite as frantic as they were. No, they're not. Some of them have found the larvae and pupae down below. It will be three or four days before the ants settle down sufficiently for Jim to begin filming. I worked at the Australian Museum for about seven years, and in that time I learned how to manipulate the environment, as it were, in making miniature dioramas, and it seemed a natural thing to combine photograph with the filming of small animals. Colony life centers around the queen whose primary function is to lay eggs. She may produce as few as one a day or as many as one every two hours. Using her sharp mandibles, she gently picks up the egg and looks for a safe place to lay it down. She must be careful that the voracious developing larvae do not steal it for food. But indeed, this time it is a larva that wins out. To complete their development into adult ants, the larvae will seal themselves inside a cocoon they make by spinning silk around debris from the tunnel floor. Having adjusted to their man-made environment, the ants go about their routine. An intruder into their silent, miniature world, Jim Frazier feels privileged to have witnessed little known behavior of one of the most primitive ants on Earth. Millions of years of isolation in Australia have protected a group of animals that today has no living relatives on Earth. Sharing features of both ancestral reptiles and early mammals, they may offer a glimpse of how more modern mammals evolved. One of these egg-laying mammals, or monotremes, is the echidna, the spiny anteater. This small, unaggressive creature has only a tiny mouth at the end of its sticklike snout and no teeth. In the daily search for ants, it relies solely on the long sticky tongue as its means of getting food. The echidna's only defenses and very effective ones they are are needle sharp spines and the ability to sink out of sight in the face of danger. Digging rapidly into the hard earth, the powerful echidna can disappear within minutes. An almost impenetrable shield will be all that remains above ground. The female echidna carries a singly leathery egg in a pouch that forms on her belly at the beginning of the breeding season. In about ten days the egg will hatch. The tiny baby nurses in the pouch for up to two months. By definition, a mammal is a warm-blooded, haired animal that suckles its young. The echidna qualifies in all respects. But it retains the distinctly reptilian characteristic of laying eggs. When and why other mammals stopped laying eggs and began to bear their young live remains a recurrent riddle of evolution yet to be solved. In eastern Australia's streams, rivers, and lakes is found the echidna's only living relative on Earth. Outwardly looking nothing whatever like its spiny cousin, the platypus does share its reptilian traits, including the laying of eggs. Although it is often called the "duckbill" platypus, its bill is actually soft, pliable, and rubbery, quite unlike a duck's. filled with sensitive nerves, it is a specialized adaptation for feeling out the insect larvae and crayfish on which the platypus feeds. Lacking teeth, adults grind their food between large horny plates in the jaws. Because the platypus spends much of the time burrowed in riverbanks, little of its life cycle is known. So unlike other animals is the platypus, it was considered a hoax when discovered in the late 1700s. Laymen still gaze quizzically at an animal that appears to be part mammal, part reptile, part bird. At an early date it was named "paradoxus". So much of a paradox is the platypus that almost two centuries later it remains a creature shrouded in mystery. One of Australia's foremost naturalists, David Fleay has been studying the platypus for close to 50 years. Today at his Fauna Reserve in Queensland visitors can enjoy an assortment of Australian exotica, but it is the platypus most tourists come especially to see. Well, he's going through his ordinary routine now. He's out feeding and swimming and when he's had enough of that, which goes on for about 10 hours, right into the night, he goes back into these tunnels, curls up, and goes to sleep. It was almost 40 years ago that Fleay gained world-wide fame as the first person to breed a platypus in captivity. It began in 1943 with a couple named Jack and Jill. Taken from the wild, they adjusted well to captivity and became unusually tame. Not long after mating had been observed, Jill stopped eating and disappeared into her nesting burrow. Fleay suspected she must be ready to lay eggs. It was roughly eight weeks before we thought, as the information was at that time, that at eight weeks the baby should be able to crawl about and swim. So we took the risk of opening up the tunnel at this point, and having looked. I felt that somehow that we were doing the wrong thing. And as it proved, it was the wrong thing. We found that she had one solitary young. Nice and fat and in good order, but it was blind and helpless and obviously couldn't either swim or walk. We'd opened that up much too soon. We left things alone and just watched carefully from that point on. And then, at a further rate, about 16 weeks altogether, we opened the back of the tunnel again and found that the baby was alive and well. It was a tremendous relief. Well, it was relayed round the world and it was announced in New York and London. The platypus, of course, is a fabulous animal. It's always attracted a lot of attention. It was considered impossible round about the 1930s for one to live in captivity for more than a few days. After all the years of effort, it was a tremendous thrill. We put the flag up that day. Four decades later not even Fleay has managed to breed the platypus again. With his assistants from the university of Queensland, Dr. Frank Carrick works after dusk and at dawn when the platypus is most active. He has been studying the animal's ecology since 1972. At least with the water being high like this, there are fewer snags... An unweighted fishing net has been laid parallel to the riverbank. The scientists check the net at regular interval guided by a light from shore. Although the net is designed so the animal can surface and breathe, there is always the danger of entanglement. Gary, I think there might be an animal in the net a bit further from us there. Would you like to just put the sop on it? Excellent. Yeah, he's gone under a bit. Go out and get him out. Okay, just ease it up here, Jim. Here he is, you little beauty. Get him out. Into the boat you go. It's male, too. His spurs. Because the male platypus has venomous spurs on his hind legs, he must be handled with extreme care. Although it's not certain, scientists speculate the spurs are used against other males in competition for females at mating time. You got the box alright. Put him in. in you go, chief. Bless you. Now, in you go. That's a boy. That's got him. There, check him. Let's have a look at him. Good boy. Once the animal is lightly sedated, Dr. Carrick can safely begin his examination. Although the platypus has existed for millions of years, significant information on its ecology has been gathered only within the last decade. And so even the most basic data on weights and measurements are invaluable. I think, really, the platypus is one of the most crucial animals of all the Australian animals that we need to know much more about. Both for the interest of seeing how patterns in the modern mammals evolved and also of course, in helping us in a rational way to ensure the platypus does continue on into future as it has done for many millions of years. It always happens, doesn't it. It's Well, starting to rain. Thanks, Jim. Alright ol' mate, you'll never notice it. Levels of hormones in the blood help the scientists determine when and how often the male platypus is sexually active. In any wildlife study, many of the important findings come from animals that have been captured before and then followed over time. Because platypuses, for the most part, remain in a relatively small home range, Carrick hopes to entrap this animal again, a metal band identifying him as Number 89. A bit of jewelry. Now, marked and identified by his captors, Number 89 is ready to be set free to return to his burrows, his secret ways. We going down with you? No. I'll put him in. no sense everyone getting wet. With the surge of scientific research in Australia over the past two decades a fascinating tableau of life has unfolded. Unlike bewildered early explorers who saw only a topsy-turvy world of improbable-looking animals, scientists of today understand how isolation and geography helped shape the evolution of Australia's wildlife. But the puzzle is far from complete. And so it remains. Haunting questions of an ancient past echo still across this remote, exotic land. Perhaps someday, one small animal with its tiny metal band may help unlock some of the long-hidden secrets of Australia, a land that time forgot. |
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