Some of Britain's most favoured spring visitors are disappearing in their thousands. Scientists say
birds such as the cuckoo (布谷鸟), whose song announces the arrival of warm weather in Britain, are
dropping in numbers.
     A typical migrant bird (候鸟) from Africa, cuckoo may no longer make its annual appearance in the
woodlands in Britain, says a scientist. Numbers of migrant birds from Africa have declined seriously in
the UK since 1995.For cuckoos the figure is 44%.The call of the cuckoo could be silenced in the near
future.
     The real problem is that there are so many different possible causes for the loss-which makes it
difficult to find out the real reasons for their decline and to prepare plans to put things right.
     The loss could be the result of changes in farmland use in Britain which are affecting the way cuckoos
breed (繁殖) when they arrive here in spring. On top of changes of land use, scientists suspect that many
cuckoos are finding it increasingly difficult to feed themselves when they come to breed in Britain. The
large insects they eat have dropped rapidly in number here.
     Climate change might be another important reason. Migrant cuckoos arrive and breed at times which
are no longer the best periods when food, such as insects, is available. Climate changes also affect timings of breeding cycles.
     Or the loss could be due to the increase of human populations in Africa and the destruction of natural
living environment where they make their homes in winter.
     Apart from these, the killing takes place in spring and autumn when cuckoos, flying from and to
Africa, cross islands in the Mediterranean Sea. They are shot in their hundreds of thousands by hunters
who just enjoy killing them for the "sport" .It is against the European Union law, but that doesn't stop it
happening.
     Sheehan, a scientist, said, cuckoos "arrive in our countryside just as the first good weather arrives.
We associate them with spring and warmth. That is why they appear so often in old English stories. They
are part of our culture-which makes the decline in their number so worrying."

1. What can be inferred from the underlined part in Paragraph 2?

A. Cuckoos may arrive in warm weather.
B. Cuckoos may rarely be seen in Britain.
C. Cuckoos may appear every two years.
D. Cuckoos may come back to the woodlands.

2. Concerning the rapid decrease in the number of cuckoos, scientists _______.

A. find it difficult to discover the real reasons
B. know few possible causes for the loss
C. have plans to put things right
D. doubt if the data are accurate

3. According to the passage, what happens in Britain that possibly causes the decline of cuckoos?

A. Many hunters kill cuckoos for fun.
B. Cuckoos' main food is getting less.
C. Policies on land use have changed.
D. Human population increases rapidly.

4.Which could be the best title for the passage?

A. Cuckoos, Who Take Away Your Food?
B. Climate Change: A Danger to Cuckoos
C. Spring May Lose Song of Cuckoos
D. A Song for England's Cuckoos