雅思阅读真题+题目+答案：MIGRATION: the birds & The migration of the Monarch butterfly

雅思阅读真题+题目+答案：MIGRATION: the birds & The migration of the Monarch butterfly

PART I: MIGRATION: the birds

Birds are forced to migrate fora number of reasons, including seasonal climate cycles, a scarcity of food or of appropriate nesting sites. Established routes are followed, many involving punishing distances overland and sea. The longest migration of any known animal is that of the Arctic tern(北极燕鸥)，which travels more than 15,000 miles from north to south ad back again.

A

What are some off the main 'cues' that research has indicated birds use in order to navigate successfully during migration? As the question suggests, there is no single answer; Keeton concluded that bird navigation is characterised by 'considerable redundancy of information' whereby birds appear to draw on more than one method. This would seem to be essential, give changeable weather conditions, the need to overfly a variable landscape and/or seascape, and the fact that some birds manage to navigate at night.

B

Rabol suggested that a bird is born with its migratory track imprinted as part of its DNA, but his ideas have been rejected by a number of experts, including Wiltschko and Wiltschko, who suggest instead that navigation techniques are an integral part of parenting. Of course, this does not account for the cuckoo, which does not remain with its parents (cuckoos lay their eggs in the nest of another bird).

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PART II: The migration of the Monarch butterfly

A

It’s fall in North America, and millions of Monarch butterflies are migrating to warmer climates for the winter, heading either to the Californian coast or to certain mountains In Mexico. These butterflies recognise the arrival of fall in the same way that we do: they feel the chill in the air. While we adapt by putting on a sweater, the situation is much more serious for the Monarchs. Temperatures below 55°F make it impossible for them to take to the air; temperatures below 40°F paralyse them. The Monarchs originated in the tropics and can't live for long at temperatures below freezing. At the same time that the air is cooling, the nectar supply in flowers that feeds the butterflies is dwindling. To survive, they begin migrating in late summer,flying with the wind to reach their winter homes.

B

Up to 100 million Monarch butterflies migrate either to California or to Mexico each year. This isn't the entire population because some never make the migration. There are more than 25 winter roosting sites along the Californian coast and about a dozen known sites in the Sierra Mad re Oriental mountains of Mexico. In both regions, butterflies depend upon trees for their survival. They cluster in pine and eucalyptus trees along the California coast and in ovamel trees in Mexico.

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雅思阅读真题题目：

Read the passage PART1 again and answer questions 1-8.

Questions 1-2

Choose the correct letter, A, B, C or D.

1 According to Wiltschko and Wiltschko,

A cuckoo behaviour supports a genetic explanation for navigation.

B Rabol's ideas on imprinting are worthy of further investigation.

C adult birds train their young to react to navigational cues.

D more studies are needed no the role of parenting in navigation.

Questions 3-8

Look at the following statements about research and the list of people below.

Match each statement to the correct person or people.

Write the correct letter, A-J.

List of people

A Baker and Mather      F Papi

B Emlen                G Rabol

C Gould                H Schlicte and Schmidt-Koening

D Keeton               I Walcott and Green

E Matthews            J Yodlowski et al

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