Part 1
The Tuatara of New Zealand
The Tuatara of New Zealand
Tuatara are lizard-like reptiles, found only in New Zealand. They are representative of ancient life forms.
Tuatara are the only living representatives of an ancient lineage of reptiles called Sphenodontia, which is over 250 million years old. Because tuatara still look like fossils of reptiles that lived during the age of dinosaurs, they are often called living fossils. Now just two species of tuatara survive, and only in New Zealand. One is the Brothers Island tuatara which, until recent reintroductions to sanctuaries -- safe places for wildlife -- only survived on North Brother Island. The other species is the common tuatara, which survives on many other offshore islands. Although the tuatara species appear similar, they have genetic differences. Tuatara bones have been found in many parts of New Zealand. Where dated, they are usually a few hundred to 5,000 years old. It is not known whether these bones are from the two living species or other species that are now extinct.
Many anatomical features distinguish tuatara from other living reptiles. For example, they have a defining pattern of openings in the skull and a unique type of haemoglobin in the blood, and males have no external reproductive organ. Adults are between 30 and 75 centimetres long and weigh between 250 and 1,200 grams. Males are larger than females and have more developed spines in the crest along the neck, back and tail.
The male tuatara courts the female by approaching her with a proud walk. Tuatara mate in late summer, and the female usually lays 6--10 eggs the following spring in a shallow nest at ground level. She may guard the nest for a few nights, then return to her burrow underground. The eggs incubate for about a year, so hatchlings emerge about the time that eggs are being laid the following season. Evidence indicates the gender of tuatara hatchlings is determined by both genetic and environmental factors. It is said that it is more likely for warmer eggs to produce male tuatara and cooler eggs to produce females. The hatchlings receive no parental care and need to find their own food.
Tuatara live for a relatively long time, reaching reproductive maturity at about 15 years, and may breed for many decades. Their maximum lifespan is not known for certain, but many tuatara have reached 80 years while still looking vigorous and healthy. Tuatara live in underground burrows and are more active at night, but will come out during the day to bask in the sun. Both sexes are territorial, and males aggressively defend their territory by posing and fighting if necessary. Teeth are their main weapons, and a bite can cause serious injury. Tuatara are carnivorous, eating invertebrates, lizards and the baby seabirds with which they often share burrows.
Tuatara were once widespread and abundant on the New Zealand mainland, but when Polynesian settlers arrived in New Zealand in about AD 1250--1300, they brought with them Pacific rats which killed tuatara. By the time of European settlement in the 1840s, tuatara were almost extinct on the New Zealand mainland. Some islands provided temporary havens, but soon these too began to be invaded by rats and other mammalian predators.
Gradually, tuatara became restricted to 32 nearshore islands. Many of these islands were tiny, some as small as only one hectare. A few, such as the Poor Knights Islands off the north-eastern coast of New Zealand and some islands in Cook Strait, were never invaded by rats and had few of the other mammals that threaten native animals. The tiny, four-hectare North Brother Island in Cook Strait was the original remaining home of the Brothers Island tuatara. However, two new populations of the Brothers Island tuatara have been created on Titi Island in the Marlborough Sounds and on Somes Island in Wellington Harbour. The common tuatara lives on islands off the north-eastern coast of New Zealand and on some islands in Cook Strait.
Tuatara can live in remarkably dense populations. Most tuatara islands have 50--100 tuatara per hectare, so an island of only ten hectares may have a population of hundreds. Larger islands with many seabirds and invertebrates, which tuatara eat, may have greater densities. The largest population is on Stephens Island, where there are estimated to be as many as 2,500 per hectare in some places and a total of at least 30,000. The total number of tuatara on all the islands is estimated to be between 50,000 and 100,000.
Legal protection was granted to tuatara and the islands they occupied in 1895, but the reptiles continued to decline. Since then, active conservation management has reversed the decline, and new populations have become established on predator-free islands. In the mid-1980s, the New Zealand Wildlife Service and its successor, the Department of Conservation, developed ways to eradicate rats from islands. Rats have now gone from almost all of the tuatara islands, making them safe for many threatened native species. In addition, the collection by conservationists of eggs for incubation in captivity, breeding in captivity and moving tuatara to rat-free islands have increased the number of islands inhabited by tuatara to 37. Many new tuatara populations are planned for islands and mainland reserves that have been freed of predators.
Questions 1--6
Do the following statements agree with the information given in Reading Passage 1?
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
1. The two living species of tuatara look alike.
2. Many of the tuatara bones that have been found are millions of years old.
3. The tails of male tuatara are a different colour from the tails of female tuatara.
4. The female tuatara lays eggs in a burrow.
5. There are higher numbers of female hatchlings than males.
6. Once they have hatched, young tuatara have to look after themselves.
Questions 7--13
Complete the notes below.
Choose ONE WORD AND/OR A NUMBER from the passage for each answer.
The Tuatara
Lifespan
- Maximum lifespan unknown
- Many live to at least 7 years old
Behaviour
- Attack other creatures with their 8
- Eat young 9 that live in the same burrows, as well as invertebrates and reptiles
Population
- Abundant until rats were introduced by 10 people
- By the 1840s, hardly any tuatara were found on the 11
- Islands off the north-eastern coast and in Cook Strait are now home to the 12 tuatara
- The density of tuatara on Stephens Island is up to 13 tuatara per hectare
Part 2
The Tasmanian Tiger
The Tasmanian Tiger
The Tasmanian tiger, or thylacine, was a carnivorous marsupial -- a meat-eating mammal which carries its young in a pouch. It was given the name "tiger" because it had striped fur and because it was ferocious. Between 24 million and 15 million years ago, many types of thylacine roamed across Australia, their powerful jaws playing a role in maintaining a balance in the ecosystems of their day. Some species were large, while others were barely the size of kittens.
But when a period of climate change cooled Australia about 12 million years ago, the numbers of these ancient thylacines began to decline. By about three million years ago, only one species was left. About 4,000 years ago, these vanished completely from Australia. Tasmania was then the last remaining place where thylacines existed. They ruled the animal life of that island unchallenged until Europeans, with sheep, dogs and a great indifference to native flora and fauna, seem to have brought about their extinction. In 1936, the last captive Tasmanian tiger died in Hobart Zoo, but no definitive evidence of the species’ complete extinction has been found. Despite this, there are many who keep searching.
In 1981, Dutch-born zoologist Hans Naarding was in Tasmania conducting a survey of Latham’s snipe, a species of endangered bird. One night, he saw an animal in the light from the searchlight mounted on his vehicle. He described it as about the size of a large dog, but with slightly sloping hindquarters and a fairly thick tail continuing straight on from its backbone. He said that it had 12 distinct stripes on its back, running down to the point where the tail began. He reported the sighting to the Director of Tasmania’s National Parks. When the news broke, said Naarding, "I was besieged by television crews, including four or five from Japan, and others from the United Kingdom, Germany, New Zealand and South America." Government and private search parties combed the region, but no further sightings were made. The tiger, as always, had escaped to its lair -- a place that many insist exists only in the imagination. Others disagree. There have been more than 4,000 claimed sightings of the animal since it supposedly died out, and the average number of claims reported to the authorities each year is now 150. So is it out there? Even experts differ in opinion.
Randolph Rose, Associate Professor of Zoology at the University of Tasmania, says that he dreamed of seeing a thylacine but is now convinced that his dream will go unfulfilled. The consensus among conservationists is that any animal with a population base of fewer than 1,000 is headed for extinction within 60 years. Sixty years ago, he says, "there was only one thylacine that we know of, and that was in Hobart Zoo. Take it from me, the tiger is gone." But Dr David Pemberton, curator of zoology at the Tasmanian Museum, states that despite scientific thinking that a relatively large number of animals is required to sustain a population, the Florida panther is down to a dozen or so animals and, while it does have some inbreeding problems, is still ticking along. After all, animals can be notoriously elusive. The strange fish known as the coelacanth, with its "proto legs", was thought to have died out with the dinosaurs until a specimen was dragged to the surface in a shark net off the coast of South Africa in 1938.
Wildlife biologist Nick Mooney has the unenviable task of investigating all so-called sightings of the tiger. It was Mooney who was first consulted in late February 2005 about the authenticity of new digital photographic images of a thylacine allegedly taken by a tourist. At face value, Mooney says, this particular account of a sighting and the photographs submitted as proof amount to one of the most convincing cases for the species’ survival that he has seen. Many other sightings have been hoaxes, and many sincere seekers are victims of obsession. "It is a blind optimism that something is, rather than something isn’t," Mooney says. "If something crosses the road, it’s not a case of ‘I wonder what that was?’ Rather, it is a case of ‘That’s a thylacine!’"
However, Mooney treats sightings at face value. "I never try to embarrass people," he says, "but the fact that I don’t pack the car immediately after they telephone can be taken as ridicule. Obsessive characters get angry that someone in my position is not out there when they think the thylacine is there."
Hans Naarding, whose sighting of a striped animal two decades ago was the highlight of a lifetime of animal spotting, remains puzzled by the time and money people waste on tiger searches. He says resources would be better applied to saving another endangered animal, the Tasmanian devil, and helping declining migratory bird populations. Could the thylacine still be out there? "Sure," Naarding says. "I know the vast south-west wilderness of Tasmania well. They could survive. But if this is the case, it will not be long before they do disappear completely." Naarding believes that any discovery of surviving thylacines would be rather pointless. "How do you bring a species back from extinction?" he asks. "What could you do with it? If there are thylacines out there, they are better off right where they are."
Questions 14--18
Complete the summary below.
Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the passage for each answer.
The thylacine was a dog-like animal which had a 14 coat and was carnivorous. It was originally spread widely throughout the mainland of 15, but started to disappear from that area around 16 ago because of climate change. In the end, thylacines were found only on the island of 17 until the arrival of 18 with their farming practices brought about a drastic reduction in thylacine numbers. The last one is thought to have died in Hobart Zoo in 1936.
Questions 19--24
Look at the following statements and the list of people below.
Match each statement with the correct person, A, B, C or D.
NB You may use any letter more than once.
List of People
A. Hans Naarding
B. Randolph Rose
C. David Pemberton
D. Nick Mooney
19. There is no longer any hope of finding a surviving Tasmanian tiger.
19
20. It would be preferable not to disturb any surviving Tasmanian tigers.
20
21. Many who claim to have seen Tasmanian tigers are not objective witnesses.
21
22. Expert estimates of numbers needed to ensure species survival may be inaccurate.
22
23. There is a great deal of international interest in Tasmanian tiger stories.
23
24. Some fresh evidence provided by a visitor to Tasmania seems credible.
24
Questions 25 and 26
Choose the correct letter, A, B, C or D.
25. Hans Naarding’s sighting of a Tasmanian tiger resulted in
26. The example of the coelacanth is used to show that
Part 3
The Cane Toad in Australia
The Cane Toad in Australia
A The cane toad was introduced into Australia in 1935 to control sugar cane pests in Queensland. One hundred and one cane toads arrived at Edmonton in June 1935. Breeding occurred almost immediately. The cane toad is tough and adaptable, as well as being poisonous throughout its life cycle, and has few predators in Australia.
B Cane toads are large, heavily built amphibians with dry, warty skin. They have a bony head, and over their eyes are bony ridges that meet above the nose. They sit upright and move in short, rapid hops. Their hind feet have leathery webbing between the toes, and their front feet are unwebbed. Adult cane toads have large swellings -- the parotoid glands -- on each shoulder behind the eardrum. Cane toads may be grey, yellowish, olive-brown or reddish-brown, and their bellies are pale with dark mottling. Average-sized adults are ten to fifteen centimetres long. The largest female measured in Queensland was 24 centimetres long and weighed 1.3 kilograms. Male cane toads are smaller and wartier than females. During the breeding season, males develop dark lumps, known as nuptial pads, on their first two fingers; these help them cling to a female while mating. Their mating call is a long, loud, purring trill. Cane toad spawn is distinctive in Australia. It is laid in long strings of transparent jelly enclosing double rows of black eggs. The spawn tangles in dense, dark masses around water plants and hangs in ropy strands if picked up.
C The natural range of cane toads extends from the southern United States to tropical South America. In 2002, cane toads occurred throughout the eastern and northern half of Queensland and had extended their range to the river catchments surrounding Kakadu National Park in the Northern Territory. In New South Wales, they occur as far south as Yamba and Port Macquarie.
D Cane toads tolerate a broad range of environmental and climatic conditions and appear able to adjust to and survive in almost any environmental system, including seawater for short periods. This largely explains their success in spreading in Australia. Cane toads are found in environments ranging from sand dunes and coastal heath to the margins of rainforests and mangroves. They are most abundant in open clearings in urban areas and in grassland and woodland.
E Cane toads eat almost anything they can swallow, including pet food, carrion and household scraps, but most of their food consists of living insects. Beetles, honey bees, ants, winged termites, crickets and bugs are eaten in abundance. Marine snails, smaller toads and native frogs, small snakes and small mammals are occasionally eaten by cane toads. The tadpoles of cane toads eat algae and other aquatic plants, which they rasp off with five rows of tiny, peg-like teeth. They also filter organic matter from the water. Large tadpoles sometimes eat cane toad eggs.
F Cane toads were introduced to Australia to eat French’s cane beetle and the greyback cane beetle. The "whitegrub" larvae of these beetles eat the roots of sugar cane and kill or stunt the plants. The Australian Bureau of Sugar Experimental Stations imported about a hundred toads from Hawaii to the Meringa Experimental Station near Cairns. The toads bred quickly, and more than 3,000 were released in the sugar cane plantations of north Queensland in July 1935. At that time, some naturalists and scientists warned of the dangers of liberating cane toads in Australia. Their protests resulted in a brief moratorium on the release of toads, but releases resumed in 1936. The protesters were right. Firstly, cane toads compete for the resources of native animals, such as food, which affects native populations. Secondly, cane toads do not have as many established predators as native animals, so their population grows quickly. Finally, some native animals that would normally feed on frogs try to eat toads and are poisoned.
G All stages of the cane toad’s life cycle are poisonous. No humans have died in Australia from cane toad poison, but overseas, people have died after eating toads and even soup made from boiled toad eggs. Cane toads are also poisonous to pets. In Hawaii, up to 50 dogs a year have died after having cane toads in their mouths. Signs of dogs being poisoned through ingestion include profuse salivation, twitching, vomiting, shallow breathing and collapse of the hind limbs. Death may occur through cardiac arrest within 15 minutes. A cane toad responds to a threat by turning sideways so that its parotoid glands are directed towards the attacker. The poison usually oozes out of the glands, but toads can squirt a fine spray for a short distance. The poison is absorbed through mucous membranes such as the eyes, mouth and nose, and in humans may cause intense pain, temporary blindness and inflammation.
Questions 27--33
Reading Passage 3 has seven paragraphs, A--G.
Choose the most suitable heading for each paragraph from the list of headings below.
* Drag a heading and drop it into the blank space.
Questions 34--37
Which paragraphs, A--G, contain the following information?
| A | B | C | D | E | F | G | |
|---|---|---|---|---|---|---|---|
| 34. Male cane toads grow protuberances during mating periods. | |||||||
| 35. The cane toad’s unique way of laying eggs in Australia. | |||||||
| 36. Opposition to the introduction of cane toads in Australia. | |||||||
| 37. The danger of eating cane toad eggs. |
Questions 38--40
Complete each of the following statements with words taken from the box below.
Word Box
flowers | hearing | hair | walking | leaves | roots | smelling | tadpoles | stalks | rope | seeds | sleeping
38. When suspended, the eggs of the cane toad resemble 38.
39. Cane toads were introduced into Australia in order to stop beetle young eating sugar cane 39.
40. The text says that dogs affected by cane toad poisoning may have problems with 40.