阅读难度：

When bombarded by noise pollution, some male birds begin to sing higher tunes, a new study has found, the Discovery News reported. And that tonal shift makes them less attractive to females.

The findings suggest that birds must make difficult trade-offs in urban areas and places where traffic and industrial noises threaten to drown them out. Either they sing less appealing songs or tones in an effort to rise above the din, or they sing the songs that make them sound appealing at the risk of not being heard at all.

Wouter Halfwerk, a behavioral ecologist at Leiden University in the Netherlands said, "It could very well be that noise pollution is interfering with reproductive decisions by females." （点击Discovery网站查看原文）

世间太吵鸟类被迫大嗓门

       据美国《探索新闻》报道，一项新的研究发现，噪音的狂轰滥炸使得雄性鸟儿开始高声唱歌。这种声调的变化降低了它们对雌性鸟儿的吸引力。

       鸟儿们在城市以及交通和工业噪音污染严重的地方必须作出一个艰难的选择，因为噪音已经要把鸟儿的歌声淹没，它们要么唱得声调缺少吸引力以压过噪音，要么就唱一些有吸引力的歌而雌性鸟儿却根本听不到。

       荷兰莱顿大学的一位行为生态学家沃尔特·哈佛沃克说：“很明显，噪音污染已经干扰到了雌性择偶繁殖的选择。”

(China.org.cn September 6, 2011)