Hi. Today we’re going to be looking at animals in urban environments and I’m going to be telling you about some research on how they’re affected by these environments.
Now, in evolutionary terms, urban environments represent huge upheavals, the sorts of massive changes that usually happen over millions of years. And we used to think that only a few species could adapt to this new environment. One species which is well known as being highly adaptable is the crow, and there’ve been various studies about how they manage to learn new skills 【Q31】. Another successful species is the pigeon, because they’re able to perch on ledges on the walls of city buildings, just like they once perched on cliffs by the sea. 【Q32】.
But in fact, we’re now finding that these early immigrants were just the start of a more general movement of animals into cities, and of adaptation by these animals to city life. And one thing that researchers are finding especially interesting is the speed with which they’re doing this – we’re not talking about gradual evolution here – these animals are changing fast. 【Q33】
Let me tell you about some of the studies that have been carried out in this area. So, in the University of Minnesota, a biologist called Emilie Snell-Rood and her colleagues looked at specimens of urbanised small mammals such as mice and gophers that had been collected in Minnesota, and that are now kept in museums there. And she looked at specimens that had been collected over the last hundred years, which is a very short time in evolutionary terms. And she found that during that time, these small mammals had experienced a jump in brain size when compared to rural mammals 【Q34】. Now, we can’t be sure this means they’re more intelligent, but since the sizes of other parts of the body didn’t change, it does suggest that something cognitive was going on. And Snell-Rood thinks that this change might reflect the cognitive demands of adjusting to city life – having to look in different places to find food, for example, and coping with a whole new set of dangers. 【Q35】
Then over in Germany at the Max Planck Institute, there’s another biologist called Catarina Miranda who’s done some experiments with blackbirds living in urban and rural areas. And she’s been looking not at their anatomy but at their behaviour 【Q36】. So as you might expect, she’s found that the urban blackbirds tend to be quite bold – they’re prepared to face up to a lot of threats that would frighten away their country counterparts. But there’s one type of situation that does seem to frighten the urban blackbirds, and that’s anything new – anything they haven’t experienced before 【Q37】. And if you think about it, that’s quite sensible for a bird living in the city.
Jonathan Atwell, in Indiana University, is looking at how a range of animals respond to urban environments. He’s found that when they’re under stress, their endocrine systems react by reducing the amount of hormones such as corticosterone into their blood 【Q38】. It’s a sensible-seeming adaptation. A rat that gets scared every time a subway train rolls past won’t be very successful.
There’s just one more study I’d like to mention which is by Sarah Partan and her team, and they’ve been looking at how squirrels communicate in an urban environment, and they’ve found that a routine part of their communication is carried out by waving their tails 【Q39】. You do also see this in the country, but it’s much more prevalent in cities, possibly because it’s effective in a noisy environment.
So what are the long-term implications of this? One possibility is that we may see completely new species developing in cities. But on the other hand, it’s possible that not all of these adaptations will be permanent 【Q40】. Once the animal’s got accustomed to its new environment, it may no longer need the features it’s developed.
So, now we’ve had a look…
Complete the notes below.
Write ONE WORD ONLY for each answer.
听前预测：定位词 animals；提示词 e.g.。此处应填名词，且通过前面的 e.g.（举例）以及下文中相对应的 the pigeon（鸽子），可以推测出此题应该填动物的种类。
题目解析：本题的定位词 animals 在文中全部被替换成 species（注意单词的发音）；题干中的 only a few 出现后，答案句通过“one species…is the crow”表示举例其中一 种动物，对应题干提示词 e.g.，并用 which 引导的从句“which is well known as being highly adaptable”来解释这种动物，恰好对应上了题干中的破折号后面的信息，如果认识 crow 这个单词，结合预测，则很容易定位答案。
听前预测：定位词 pigeon、walls of city buildings；提示词 similar to。此处应填名词，可能是复数，且该名词应该是与墙相似的建筑 / 地方。
题目解析：定位词 pigeon、walls of city buildings 之后先是出现了 just like，对应题干提示词 similar to，然后马上出现了答案对应信息“they once perched on cliffs by the sea”，其中 perch 意为“栖息”，是专用于描述鸟类的一个动词。之前预测的答案词是与墙相似的东西，而 cliffs 意为“悬崖峭壁”，正好对应题干的含义，因此答案为 cliffs。
听前预测：定位词 animals、adapting；提示词 unusual。此处应填名词，且从题干中 adapting 搭配的介词 with 可以推测出该名词为与“适应”相关的一个特性，而且是比较特殊的。
题目解析：in fact 作为题干原词出现得比较早，但是之后的句子里并没有出现能和提示词 unusual 相对应的表达，直到听到“one thing that researchers are finding especially interesting”，该句是 that 引导的定语从句，其中 especially 用来强调先行词 one thing，而 especially 与 unusual 相对应，都意为“与普通情况不一样”，因此可以通过句子主干“one thing…is the speed”得知答案词为 speed，且在此之后出现的 gradual、fast 都是描述速度的词。
听前预测：定位词 size；提示词 increased。此处应填名词。先要理解 their 指代的是前一句话中的 mammal specimens，因此这道题的答案可能为动物身体的某个部分，且这个部分的体积增加了。
题目解析：题干中的 she found 原词重现，their 则变成了具体指代的 mammals；注意，关键信息 a jump 要理解为“增加，上升”才能对应上题干中的increased，因此 a jump in brain size 可通过 jump 与 increased 的同义替换以及 size 的原词重现定位为答案句，而 brain 一词又恰好符合预测，因此答案为 brain。有时 of 构成的表 示从属关系的短语可能会替换成“名词 + 名词”的名词词组，语序会颠倒一下，因此会在定位词之前听到答案词，如：题干中的 size of their brain 在文中替换成 了 brain size。
听前预测：定位词 sources of、new；提示词 and、dangers。此处应填名词。题干中的 locate 意为“寻找地方”；source of… 意为“……的来源”，因此要填的单词应该是动物需要的某种东西。
题目解析：当听到“And Snell-Rood thinks that”时，通过 and 得知接下来听到的是 Snell-Rood 的第二个观点，也就是“having to look in different places”，与题干 need to locate new sources of 相对应，而且答案词 food 之后出现了 and 连接的并列关系“and coping with…dangers”，其中提示词 dangers 原词出现，结合预测可以确定答案为 food。
听前预测：定位词 Catarina Miranda、blackbirds；提示词 focused on。此处应填名词，且从答案词与 of urban and rural blackbirds 的搭配可以推测出该词与乌鸫有关，可能是鸟类的身体部位或者行为特性。
题目解析：首先听到定位词 Catarina Miranda、blackbirds，然后听到了答案对应信息“she’s been looking not at their anatomy but at their behaviour”，其中 look at 对应题干提示词 focused on ；需要注意 not…but… 这个表达，not 后面的词是被否定的干扰项，正确答案往往在 but 之后，因此答案为behaviour(s)/behavior(s)。
听前预测：定位词 urban birds、afraid of ；提示词 but、were。此处应填修饰 situation 的形容词。从题干中的 but 可以看出，需要重点听转折词之后的信息。
题目解析：通过 bold 与题干中 braver 的同义替换可以定位本题大致位置，再仔细听转折词 but 可以定位答案句的位置，然后听到“there’s one type of situation that does seem to frighten the urban blackbirds”，其中 situation 为题干中的原词，frighten 与题干的 afraid of 为同义替换，之后“that’s anything new”中仅有一个形容词 new，因此答案为 new。
听前预测：定位词 animals、hormones；提示词 respond to。此处应填名词，可能是动物对某种情况的反应。
题目解析：首先听到的人名 Jonathan Atwell 以及 respond to urban environments 都是题干中的原词，所以在此之后听到的句子应与答案相关。这道题如果只关注 respond to 的替换词则较难定位答案，要理解“when they’re under stress”意为“动物在有压力的情况下”，其中 stress 这个名词与我们预测答案时所想的“某种情况”相关，且之后出现的词汇都为生物学的专业术语，这类词一般不作考点，答案应该不在其中，因此答案为 stress。
听前预测：定位词 Sarah Partan、squirrels ；提示词 their。此处应填名词，可能为复数。先理解题干中的 their 意为“松鼠的”，再结合整句话的含义可以推测出答案词为松鼠的身体部位或者某个能力。
题目解析：在定位词 Sarah Partan、squirrels 出现之后听到了答案对应信息“a routine part of their communication is carried out by waving their tails”，其中 carried out by 对应题干中的 use，而之后的 tails 符合我们对答案词的预测，因此答案为 tails。
听前预测：定位词 animals、cities、changes ；提示词 However、not。此处应填形容词，且为能修饰 changes 的词汇。
题目解析：题干中的转折词 However 和否定词 not 可以帮助定位答案句，文中“But on the other hand”这句话可以明显体现转折的意味，然后听到了答案对应信息“not all of these adaptations will be permanent”，其中否定词 not 为原词重现 ；adaptation 意为“动物为了适应而做的改变”，对应定位词 changes，而 permanent 又是这句话中唯一的形容词，且符合之前的预测，因此答案为 permanent。