北极燕鸥是一种特别的鸟。迁徙时，它们从北极圈飞往南极圈，再飞回起点，整个旅程非比寻常，历时一年之久。这种鸟的迁徙路线在全球鸟类中属最长，但它们在途中也会停下来歇歇脚。北极燕鸥在英国北部繁殖，以北大西洋中部的鱼类为食，为漫长的旅程积攒体力。本期节目介绍这种鸟漫长而艰苦的迁徙之旅。

词汇：bird migration 鸟类迁徙

Back in 2010, an international research team fitted tracking devices to birds they believed to be special – Arctic terns. And it turns out they were right, as described in US journal, PNAS. The Arctic tern has an extraordinary year-long migration from the Arctic Circle to the Antarctic Circle and back again.

What does this route look like? Arctic terns begin their migration in the Northern hemisphere in the summer, which is breeding season. As it gets colder and darker, turning to winter, the birds fly southward, parallel to the coast of South America or hugging the coast of the African continent to reach their winter feeding ground, the Antarctic Circle. And they do not always fly in a straight line. While heading back up north, their flight path mimics an S-shape which they follow to save energy while navigating the wind systems in the different hemispheres. This journey is a round-trip of up to 35,000km long, which makes the Arctic tern's migration the longest of any bird. Plus, they see more daylight than any other animal on Earth!

But, on this epic journey, the birds do take some well-deserved breaks. Heading northward, the population stops on the north and west coast of the UK to breed. A female lays one to three eggs in a nest, and after an incubation period of around three weeks, they hatch, and fluffy brown and grey chicks emerge. Meanwhile, the adult birds feed in the shallow coastal waters on fish, such as sand-eels. In contrast, while heading south, the birds appear to stop off in the middle of the North Atlantic Ocean, where they indulge on fish and zooplankton, preparing themselves for their long journey ahead.

So, if you ever see a little black and white bird with red legs and a red beak, show them some appreciation. They have flown a long way to see you! 

词汇表

tracking device 跟踪装置
Arctic tern 北极燕鸥
migration 迁徙
Arctic Circle 北极圈
Antarctic Circle 南极圈
route 路线
Northern hemisphere 北半球
breeding 繁殖
southward 向南地
continent 大陆
feeding ground 觅食地
flight path 飞行路线
wind system 风系
round-trip 往返旅程
lay 产（蛋）
nest 鸟窝，鸟巢
incubation 孵化
hatch （雏鸟）孵出，破壳而出
chick 雏鸟
stop off 中途停留
zooplankton 浮游动物
beak （鸟）嘴，喙

测验与练习

1.  阅读课文并回答问题。

1. How long is the migration of an Arctic tern?

2. Why do the birds fly south in the winter?

3. True or False? When flying north, Arctic terns fly in a straight line.

4. Where and why do the birds stop in the UK?

5. What do Arctic terns eat?

2.  选择意思恰当的单词或词组来完成下列句子。

1. We're travelling up the country but don't know which _______ to take.  

route                       continent                          migration                 beak

2. Unfortunately, microplastics have been found in the _______ of many fish.    

round-trip                feeding grounds               flight paths              wind systems

3. I can't swim, so I usually stay in the _______ end of the pool.  

north                       southward                        shallow                    fluffy

4. We watched two birds building a _______ in the oak tree in our garden.

chick                       zooplankton                     nest                          incubation

5. The children were allowed to _______ the penguins at the zoo today!

lay                           hatch                                breed                       feed

答案

1. 阅读课文并回答问题。 

1. How long is the migration of an Arctic tern?
The Arctic tern has an extraordinary year-long migration.

2. Why do the birds fly south in the winter?
Because it gets colder and darker in the Northern hemisphere.

3. True or False? When flying north, Arctic terns fly in a straight line.
False. While heading back up north, the flight path mimics an S-shape.

4. Where and why do the birds stop in the UK?
The population stops on the north and west coast of the UK to breed.

5. What do Arctic terns eat?
Fish, such as sand-eels, and zooplankton.

2.  选择意思恰当的单词或词组来完成下列句子。

1. We are travelling up the country but don't know which route to take.

2. Unfortunately, microplastics have been found in the feeding grounds of many fish.

3. I can't swim, so I usually stay in the shallow end of the pool. 

4. We watched two birds building a nest in the oak tree in our garden. 

5. The children were allowed to feed the penguins at the zoo today!