評論
打印
Using the examples of the albatross and the fulmar,
請以信天翁和管鼻藿為例
explain two special adaptations that have developed to help sea birds find food.
解釋說明海鳥為了尋找食物而進(jìn)化出的兩項(xiàng)特殊能力。
Listen to part of a lecture in a biology class.
請聽生物課上的部分內(nèi)容。
Today, I want to talk about sea birds.
今天，我想跟你們討論一下海鳥。
Now, sea birds hunt and eat fish and, well,
海鳥捕魚并以魚為食，
their food can be hard to find because their food source is spread out over a large expanse of water.
有時候它們要找到食物還是很困難的，因?yàn)樗鼈兊氖澄飦碓幢椴加趶V闊的水域。
So what sea birds have done is that, over time, they've made adaptations:
所以海鳥做的就是：經(jīng)過時間的推移，它們做出了一些改變
they've developed special characteristics that help them find food.
進(jìn)化出了能夠幫助它們找到食物的特殊體征。
One adaptation involves the length of the bird's wings.
一種改變涉及了鳥類翅膀的長度。
The albatross, for example, is a large sea bird that spends most of its life flying over ocean waters in search of food,
比如信天翁，一種大型海鳥，一生大部分時間都在海面上飛行以尋找食物，
fish to feed itself and to carry back to the nest for its chicks.
尋找它自己吃的以及銜回巢中喂養(yǎng)幼鳥的魚。
Now, most birds flap their wings up and down when they fly, which uses up a lot of energy,
大部分鳥類在飛行的時候都要上下拍打翅膀，這樣會消耗很多體力，
but the albatross has these special long wings that it can hold perfectly still.
但是信天翁長著特別的長翅膀，能夠完美地保持不動。
It's able to fly without moving its wings up and down.
它不需要上下拍打翅膀就能飛行。
These long wings allow it to glide or float on the wind, and this uses very little energy.
這對長長的翅膀使它能夠順著風(fēng)滑翔或者飄浮，而這么做幾乎不消耗體力。
This is important because as I said the albatross has to cover huge expanse of ocean to locate food,
這一點(diǎn)至關(guān)重要，因?yàn)榫拖裎艺f過的，信天翁得飛過巨大的一片海面才能找到食物，
sometimes up to eleven hundred miles a day.
有時甚至一天要飛一千一百英里。
Because of its long wings, it can glide along over the ocean using little energy as it searches for food.
多虧了這雙長長的翅膀，信天翁尋找食物的時候可以用很少的力氣滑翔在海面上。
Another important adaptation of many sea birds is an acute, highly developed sense of smell.
很多海鳥進(jìn)化出的另一個重要的能力就是一個精準(zhǔn)的、高度發(fā)達(dá)的嗅覺。
Take the fulmar, like the albatross, the fulmar needs to find foods that scatter far out over the ocean,
就拿管鼻藿來說吧，跟信天翁一樣，管鼻藿要找的食物也分散在大海遠(yuǎn)處的海域，
but the fulmar has a rather unusual advantage: it has tiny tubes inside the nose holes in its beak,
但是它有一個特別罕見的優(yōu)勢：在它喙上的鼻孔里面有一些細(xì)小管狀器官，
and these special tube-shaped nostrils help it to pick up the scent of food.
這些特殊的管狀鼻孔能幫助它捕捉到食物的氣味。
Now, this highly-developed sense of smell is especially important because the fulmar's main source of food, plankton,
這種高度發(fā)達(dá)的嗅覺尤其重要，因?yàn)楣鼙寝降闹饕澄飦碓淳褪歉∮紊铩?/div>
are tiny organisms that are hard to see, but they give off a very sharp, distinctive odor.
這些浮游生物是一些肉眼幾乎看不見的極小的生命體，但是它們會發(fā)出一種很強(qiáng)烈的、獨(dú)具特色的氣味。
so when fulmars are flying around looking for food, they may not be able to see them,
所以四處飛行尋找食物的時候，管鼻藿雖然看不見這些浮游生物，
but they can find the plankton by smelling them even from far away.
但即使在很遠(yuǎn)的地方都能通過氣味找到它們。
