Using the examples of the albatross and the fulmar,
请以信天翁和管鼻藿为例
explain two special adaptations that have developed to help sea birds find food.
解释说明海鸟为了寻找食物而进化出的两项特殊能力。
Listen to part of a lecture in a biology class.
请听生物课上的部分内容。

Today, I want to talk about sea birds.
今天，我想跟你们讨论一下海鸟。
Now, sea birds hunt and eat fish and, well,
海鸟捕鱼并以鱼为食，
their food can be hard to find because their food source is spread out over a large expanse of water.
有时候它们要找到食物还是很困难的，因为它们的食物来源遍布于广阔的水域。
So what sea birds have done is that, over time, they've made adaptations:
所以海鸟做的就是：经过时间的推移，它们做出了一些改变
they've developed special characteristics that help them find food.
进化出了能够帮助它们找到食物的特殊体征。
One adaptation involves the length of the bird's wings.
一种改变涉及了鸟类翅膀的长度。
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，一种大型海鸟，一生大部分时间都在海面上飞行以寻找食物，
fish to feed itself and to carry back to the nest for its chicks.
寻找它自己吃的以及衔回巢中喂养幼鸟的鱼。
Now, most birds flap their wings up and down when they fly, which uses up a lot of energy,
大部分鸟类在飞行的时候都要上下拍打翅膀，这样会消耗很多体力，
but the albatross has these special long wings that it can hold perfectly still.
但是信天翁长着特别的长翅膀，能够完美地保持不动。
It's able to fly without moving its wings up and down.
它不需要上下拍打翅膀就能飞行。
These long wings allow it to glide or float on the wind, and this uses very little energy.
这对长长的翅膀使它能够顺着风滑翔或者飘浮，而这么做几乎不消耗体力。
This is important because as I said the albatross has to cover huge expanse of ocean to locate food,
这一点至关重要，因为就像我说过的，信天翁得飞过巨大的一片海面才能找到食物，
sometimes up to eleven hundred miles a day.
有时甚至一天要飞一千一百英里。
Because of its long wings, it can glide along over the ocean using little energy as it searches for food.
多亏了这双长长的翅膀，信天翁寻找食物的时候可以用很少的力气滑翔在海面上。
Another important adaptation of many sea birds is an acute, highly developed sense of smell.
很多海鸟进化出的另一个重要的能力就是一个精准的、高度发达的嗅觉。
Take the fulmar, like the albatross, the fulmar needs to find foods that scatter far out over the ocean,
就拿管鼻藿来说吧，跟信天翁一样，管鼻藿要找的食物也分散在大海远处的海域，
but the fulmar has a rather unusual advantage: it has tiny tubes inside the nose holes in its beak,
但是它有一个特别罕见的优势：在它喙上的鼻孔里面有一些细小管状器官，
and these special tube-shaped nostrils help it to pick up the scent of food.
这些特殊的管状鼻孔能帮助它捕捉到食物的气味。
Now, this highly-developed sense of smell is especially important because the fulmar's main source of food, plankton,
这种高度发达的嗅觉尤其重要，因为管鼻藿的主要食物来源就是浮游生物。
are tiny organisms that are hard to see, but they give off a very sharp, distinctive odor.
这些浮游生物是一些肉眼几乎看不见的极小的生命体，但是它们会发出一种很强烈的、独具特色的气味。
so when fulmars are flying around looking for food, they may not be able to see them,
所以四处飞行寻找食物的时候，管鼻藿虽然看不见这些浮游生物，
but they can find the plankton by smelling them even from far away.
但即使在很远的地方都能通过气味找到它们。