Tuatara are lizard-like reptiles, found onlyin New Zealand. They are representative of ancient life forms Tuatara are theonly living representatives of an ancient lineage of reptiles calledSphenodontia, which is over 250 million years old. Because tuatara still lookslike fossils of reptiles that lived during the age of dinosaurs, they are oftencalled living fossils. Now just two species of tuatara survive, and only in NewZealand. One is the Brothers Island tuatara which, until recent re-introductionsto sanctuaries (safe places for wildlife), only survived on North BrotherIsland. The other species is the common tuatara, which survives on many otheroffshore islands. Although the tuatara species appear similar, they havegenetic differences. Tuatara bones have been found in many parts of NewZealand. Where dated, they are usually a few hundred to 5,000 years old. It isnot known whether these bones are from the two living species or other speciesthat are now extinct.
Many anatomical features distinguish tuatarafrom other living reptiles - for example, they have a defining pattern ofopenings in the skull and a unique type of hemoglobin in the blood, and maleshave no external reproductive organs. Adults are between 30 and 75 centimetreslong and weigh between 250 and 1.200 grams. Males are larger than females, andhave more developed spines in the crest along the neck, back and tail.
The male tuatara courts the female byapproaching her with a proud walk. Tuatara mate in late summer, and the femaleusually 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 thateggs are being laid the following season. Evidence indicates the gender oftuatara hatchlings is determined by both genetic and environmental factors. Itis said that it is more likely for warmer eggs to produce male tuatara, andcooler eggs to produce females. The hatchlings receive no parental care andneed to find their own food.
Tuatara live for a relatively long time,reaching reproductive maturity at about 15 years, and may breed for manydecades. Their maximum lifespan is not known for certain, but many tuatara havereached 80 years still looking vigorous and healthy. Tuatara live inunderground burrows and are more active at night, but will come out during theday to bask in the sun. Both sexes are territorial, and males aggressivelydefend their territory by posing and fighting if necessary. Teeth are theirmain weapons, and a bite can cause serious injury. Tuatara are carnivorous,eating invertebrates, lizards and the baby seabirds with which they often shareburrows.
Tuatara were once widespread and abundant onthe New Zealand mainland, but when Polynesian settlers arrived in New Zealand,in about 1250-1300 AD, they brought with them Pacific rats which killedtuatara. By the time of European settlement, in the 1840s, tuatara were almostextinct 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 32nearshore islands. Many of these islands were tiny, some as small as only onehectare. A few, such as the Poor Knights common tuatara live on islands off thenorth-eastern coast of New Zealand, and on some islands in Cook Strait. TheBrothers Island tuatara survived only on the of the Brothers Island tuatarahave been created on Titi Island in the Marlborough Sounds, and on Somes Islandin Wellington Harbour.
Tuatara can live in remarkably densepopulations. Most tuatara islands have 50- 100 tuatara per square hectare - soan island of only 10 hectares may have a population of hundreds. Larger islandswith many seabirds and invertebrates, which tuatara eat, may have greaterdensities. The largest population is on Stephens Island, where there areestimated to be as many as 2,500 per hectare in some places, and a total of atleast 30,000. The total number of tuatara on all the islands is estimated to bebetween 50,000 and 100,000.
Legal protection was granted to Tuatara andthe islands they occupied in 1895, but the reptiles continued to decline. Sincethen, active conservation management has reversed the decline, and newpopulations have become established on predator-free islands. In the mid-1980sthe New Zealand Wildlife Service and its successor, the Department ofConservation, developed ways to eradicate rats from islands. Rats have now gonefrom almost all of the Tuatara Islands, making them safe for many threatenednative species. In addition, the collection by conservationists of eggs forincubation in captivity, breeding in captivity, and moving tuatara to ratislands off the Northland coast, or Stephens Island in Cook Strait, were neverinvaded by rats and had few of the other mammals that threaten native animals.The tiny, 4-hectare North Brother Island, is in Cook Strait. However, two newpopulations free islands, have increased the number of islands that areinhabited by tuatara to 37. Many new tuatara populations are planned forislands and mainland reserves that have been freed of predators.
Questions 1-6
Do the following statements agree with theinformation given in Reading Passage? In boxes 1-6 on your answer sheet, write
TRUE if the statement agrees with theinformation FALSE if the statement contradicts the information NOT GIVEN ifthere is no information on this
1 The two living species of tuataralook alike
2 Many of the tuatara bones that havebeen found are millions of years old.
3 The tails of male tuatara are adifferent colour from the tails of female tuatara.
4 The female tuatara lays eggs in aburrow.
5 There are higher numbers of femalehatchlings than males.
6 Once they have hatched, young tuatarahave to look after themselves.
Questions 7 -13
Complete the notes below.
Choose ONE WORD AND/OR A NUMBER from thepassage for each answer Write your answers in boxes 7-13 on your answer sheet.
The tuatara
Lifespan
-maximum lifespan unknown
-many live to at least 7.......................years old
Behaviour
-attack other creatures with their 8.....................
-eat young 9...................... thatlive in the same burrows, invertebrates and reptiles
Population
-abundant until rats were introducedby 10....................... people
-by the 1840s, hardly any tuatara found onthe 11.....................
-islands off the north-eastern coast and inCook Strait now home to the 12....................... tuatara
-Brothers Island tuatara found on NorthBrother Island
-density of tuatara on Stephens Island is upto 13....................... tuatara for every hectare
Protection of the species
-tuatara population dropped until rats wereeradicated from the islands
-eggs were gathered by the Department ofConservation
答案：
1. TRUE
2. FALSE
3. NOT GIVEN
4. FALSE
5. NOT GIVEN
6. TRUE
7. 80
8. tech
9. Seabirds
10. Polynesian
11. Mainland
12. common
13. 2500
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