Australia’s frogs are having trouble finding love. Traffic noise and other sounds of city life, such as air conditioners and construction noise, are drowning out the mating calls of male frogs in urban areas, 1eading to a sharp drop in frog populations. But, in the first study of its kind, Parris, a scientist at the University of Melbourne has found that some frogs have figured out a way to compensate for human interference in their love lives.
A male southern brown tree frog sends out a mating call when he’s looking for a date. It is music to the ears of a female southern brown tree frog. But, add the sounds of nearby traffic and the message just is not going out. Parris spent seven years studying frogs around Melbourne. She says some frogs have come up with an interesting strategy for making themselves heard.
“We found that it’s changing the pitch of its call, so going higher up, up the frequency spectrum, being higher and squeakier, further away from the traffic noise and this increases the distance over which it can be for heard,” Parris said.
The old call is lower in pitch. The new one is higher in pitch.
Now, that may sound like a pretty simple solution. But, changing their calls to cope with a noisy environment is actually quite extraordinary for frogs. And while the males have figured out how to make themselves heard above the noise, Parris says it may not be what the females are looking for.
“When females have a choice between two males calling, they tend to select the one that calls at a lower frequency because, in frogs, the frequency of a call is related to body size. So, the bigger frogs tend to call lower,” she explained. “And so they also tend to be the older frogs, the guys perhaps with more experience, they know what they’re doing and the women are attracted to those.”
Frog populations in Melbourne have dropped considerably since Parris began her research, but it is not just because of noise. Much o
根据Parris和first…study定位到第一段。本段首先提到由于城市生活的噪音使得城市地区的青蛙在求偶时出现问题,也就是这一它们的生存环境对它们求偶的影响,而Parris就是研究这个问题的。同时,通读全文可知主要讲由于人类噪音干扰,青蛙改变叫声来求偶。全文围绕“mating calls”展开,最后一段又指出青蛙数量下降是由于干旱,属于生存环境方面。因此选项C为正确答案。第一段最后一句虽然提到“love lives”,但是强调的是Parris发现青蛙如何来弥补人类对它们的“love lives”的影响,研究的不是love lives本身,因此选项B不正确。Parris主要研究的是人类噪音对其求偶的影响,选项D“对青蛙的影响”太过宽泛,因此排除。
京胡属( )乐器。
《亚威农少女》是( )绘画的代表作品。
2012年1-4季度该市人均可支配收入中,增长量最大的是:( )
携带绝密级载体外出的,必须报()备案。
聘用单位应当对文职人员进行全面考核,其考核内容包括()。
根据领导生命周期理论,工作能力不足但积极性较高的下属适用的领导风格为( )。