英语听力：探索发现 2013-03-10 猛玛象进城记 Mammoths to Manhattan—18

 This mass roosting takes place soon after the summer nesting season. It’s a chance for the birds to molt¹ before they fly south for the winter. As Vaux’s swift numbers reach a peak in mid² September, they attract attention from the locals. Coopers hawks³ and peregrines pluck a meal from the tumbling mass of birds. In as little as 20 minutes, as many as 40,000 swifts pack into the chimney for the night.

 

While a Portland chimney has become a substitute for a tree, another roosting creature has chosen a road bridge in Austin, Texas as its cave. Visitors to Austin have to wait till evening for a glimpse of what lurks⁴ within the bridge. 

 

As the sun goes down, Mexican free-tailed bats begin a breath-taking commute⁵ out of the city. This exodus⁶ only takes place in summer. Free-tailed bats arrive in Texas for the spring, returning to Mexico for the winter. More than a million of them leave the city at dusk and head into surrounding countryside to feed on insects. The sky over Austin swarms⁷ with these aerial commuters.

1 molt   

n.换毛，脱皮，换毛期

参考例句：

• The fourth time they molt,they change into pupae.换第四次皮时，它们蜕变成蛹。
• This veterinary product is very effective in preventing animal molt.这种兽药对于防治兽类掉毛很有效。

2 mid   

adj.中央的，中间的

参考例句：

• Our mid-term exam is pending.我们就要期中考试了。
• He switched over to teaching in mid-career.他在而立之年转入教学工作。

3 hawks   

鹰( hawk的名词复数 )； 鹰派人物，主战派人物

参考例句：

• Two hawks were hover ing overhead. 两只鹰在头顶盘旋。
• Both hawks and doves have expanded their conditions for ending the war. 鹰派和鸽派都充分阐明了各自的停战条件。

4 lurks   

n.潜在，潜伏；（lurk的复数形式）vi.潜伏，埋伏（lurk的第三人称单数形式）

参考例句：

• Behind his cool exterior lurks a reckless and frustrated person. 在冷酷的外表背后，他是一个鲁莽又不得志的人。 来自《简明英汉词典》
• Good fortune lies within Bad, Bad fortune lurks within good. 福兮祸所倚，祸兮福所伏。 来自互联网

5 commute   

vi.乘车上下班；vt.减(刑)；折合；n.上下班交通

参考例句：

• I spend much less time on my commute to work now.我现在工作的往返时间要节省好多。
• Most office workers commute from the suburbs.很多公司的职员都是从郊外来上班的。

6 exodus   

v.大批离去，成群外出

参考例句：

• The medical system is facing collapse because of an exodus of doctors.由于医生大批离去，医疗系统面临崩溃。
• Man's great challenge at this moment is to prevent his exodus from this planet.人在当前所遇到的最大挑战，就是要防止人从这个星球上消失。

7 swarms   

蜂群，一大群( swarm的名词复数 )

参考例句：

• They came to town in swarms. 他们蜂拥来到城里。
• On June the first there were swarms of children playing in the park. 6月1日那一天，这个公园里有一群群的孩子玩耍。