英语听力：探索发现 2013-02-20 猛玛象进城记 Mammoths to Manhattan—10

 Where purple martins had once laid their eggs in hollow threes, in time, they came to rely almost totally on people to provide nests for them.

 

These artificial nests were made from dried out squashes known as gourds¹. The shape made them perfect nesting sites for these birds. But what triggered this special relationship in the first place? It’s possible the insect-eating martins helped to control pests living around Native American camps. Whatever the original reason, the traditional tie between people and purple martins survives to this day. But now, in keeping with the modern world, hollow gourds have often been replaced by high-rise apartment blocks. 

 

This special relationship between purple martins and people is one of the few in North America to cross cultural boundaries between native groups and European settlers. Other animals to cross this cultural divide did so for different reasons. 

 

More than 50 million wild turkeys were living in North America when the first Europeans arrived. They were occasionally hunted by the native people, but the European settlers had a taste for turkey and they took this to extremes. As hunting intensified², wild turkey populations plummeted³. 

 

The turkey became a central part of Thanksgiving Day celebrations and was almost hunted to extinction⁴.

1 gourds   

n.葫芦( gourd的名词复数 )

参考例句：

• Dried gourds are sometimes used as ornaments. 干葫芦有时用作饰品。 来自《简明英汉词典》
• The villagers use gourds for holding water. 村民们用葫芦盛水。 来自《简明英汉词典》

2 intensified   

v.（使）增强， （使）加剧( intensify的过去式和过去分词 )

参考例句：

• Violence intensified during the night. 在夜间暴力活动加剧了。
• The drought has intensified. 旱情加剧了。 来自《简明英汉词典》

3 plummeted   

v.垂直落下，骤然跌落( plummet的过去式和过去分词 )

参考例句：

• Share prices plummeted to an all-time low. 股票价格暴跌到历史最低点。
• A plane plummeted to earth. 一架飞机一头栽向地面。 来自《简明英汉词典》

4 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。