节目资讯
刊物:空中英语教室
日期:2014-04-15
难易度:High
关键字:approximately, habitat, starvation, debris, raptor, predator
Hello, everyone.
My name is Gabe.
And welcome to Studio Classroom.
My name is Carolyn.
And today we are continuing our lesson on Rulers of the Sky.
Yesterday we learned a little bit about some of the birds of prey: golden
eagles, bald eagles and harpy eagles.
But there are many more birds of prey than just these three.
So open up your magazine and let's begin reading the first section of our
lesson: All shapes and sizes.
Rulers of the Sky.
All shapes and sizes.
The approximately 420 species of birds of prey come in many sizes and shapes.
The smallest falcon weighs just 28 grams, while the Andean condor weighs in at
13 kilograms and has a wingspan of more than three meters!
Birds of prey, or raptors, can be found on every continent and in habitats from
dense tropical jungles to icy mountainsides to hot, dry deserts.
These birds play an important role in the balance of nature.
Without them, there would soon be too many animals for the amount of food
available, and many animals would die of starvation.
(Music).
Hi, everyone. I'm Michelle.
(Chinese).
Wow! There are so many different types of birds of prey.
In the opening sentence we learn that there are approximately 420 species that
are considered to be birds of prey.
That is a very large number.
Now yesterday we learned about three different types of eagles.
But eagles aren't the only bird in this category.
There are many other names used to describe the different species.
Can you name any?
Well, birds of prey are birds that hunt and eat other animals, so let's think
about birds that hunt.
One type is a hawk.
These are usually smaller than eagles.
They have sharp, curved beaks and claws, and they also have keen eyesight.
Another bird similar to hawks is called a falcon, but they have several distinct
differences from hawks.
One difference is that falcons have long, pointed wings while hawks have
shorter, round wings.
And yesterday we learned that the bald eagle could plummet to the ground at
speeds up to 322 kilometers per hour.
But this isn't actually the fastest bird of prey.
One type of falcon can dive to the ground at speeds up to 360 kilometers per
hour.
That is an extremely fast bird.
Now there are many other types of birds of prey as well, such as kites, owls,
ospreys and condors.
These birds come in many different shapes and sizes.
And Liz wants to talk to us about that phrase in the Grammar Gym.
So let's join her now.
Hi, friends.
Welcome to the Grammar Gym.
My name is Liz.
Here's our Grammar Tip sentence for today.
The approximately 420 species of birds of prey come in many sizes and shapes.
Our focus is on the phrase: to come in many something and something.
This phrase is used to talk about how something is available or can be found in
various forms.
Now in the case of today's sentence, the writer is just saying that there are
about 420 species of birds of prey, and they are all in different sizes and
shapes.
Not only can we use this phrase, to come in many something and something, to
talk about birds and animals,
but we can also use it to talk about other things from nature, such as plants
and produce like:
Many people think chili peppers are all long and red; but in reality, chili
peppers come in all shapes and colors.
We can also use this phrase to talk about commercial goods like:
Although trench coats started out as a long khaki color military coat, they now
come in many colors and lengths.
So give this phrase a try.
Think of something that actually is available in many different forms, and then
practice using this phrase.
If you need to see some more example sentences, they're available in today's
Grammar Tip section in your magazine.
That's it for today.
This is Liz from the Grammar Gym.
See you next time.
Thank you, Liz.
Well, birds of prey come in many shapes and sizes.
And in our lesson we learn about some of the smallest and largest of these
birds.
Yes, we learn that one type of falcon only weighs 28 grams.
That sounds like the most adorable bird of prey, especially when you compare its
cute size to that of the Andean condor.
Ooh. Now this bird is certainly not cute.
This giant bird weighs in at 13 kilograms.
Now if you remember from our lesson yesterday, the bones of birds are hollow so
that they can fly.
This means that most birds don't weigh very much.
But the Andean condor weighs in at 13 kilograms, so it must be a huge bird.
And we are using a special phrase to describe this bird's weight.
We've been saying "weighs in at." How do we use this phrase, Gabe?
Well, "weigh in" means that you measure how heavy something is.
If someone is trying to reach a certain goal, they could say that they weigh in
once a week.
That means that they see how much they weigh once a week.
Right.
So if you say something weighs in at a certain number, that means you are saying
how much something weighs.
We usually use this type of phrase when we want to emphasize how heavy or light
something is.
For example, the professional wrestler weighed in at 187 kilograms.
He was a very large wrestler.
That is a very heavy person.
Yep.
But you can also use this to describe how light something is.
For example, the smallest falcon weighs in at just 28 grams.
The word "just" also helps to emphasize that the number is very small.
Right.
Well, back to the Andean condor, not only is it one of the heaviest birds of
prey, it also has a wingspan of more than three meters.
This is one huge bird.
Fortunately, though, this type of bird of prey actually doesn't hunt large
animals.
This may be a bit surprising, but Andean condors actually hunt for small animals
like mice and eat large animals that are already dead.
So if another animal killed a deer, then the Andean condor would eat it.
But it wouldn't hunt for deer on its own.
Interesting.
Well, these animals are very interesting birds of prey, which are also known as
raptors.
Birds of prey can be found on every continent in the world and in a variety of
different habitats.
That must be why they are all shapes and sizes.
These differences allow them to live in many types of environments like deserts,
mountains, jungles and even on the beach.
This is very true.
Now one thing that is important to know about these birds is that they are at
the top of the food chain in their habitats.
Now we should talk about that term, the food chain.
Carolyn, what is the food chain?
We use this term to describe a series of living things that are linked to one
another because one thing eats the thing that is below it on the chain.
Now this might sound a little confusing at first, so let's use an example.
Good idea, OK.
If we have a habitat that is a grassy field, we could put grass at the bottom of
the chain.
Above grass would be deer because deer eat grass.
Above deer would be wolves because wolves eat deer.
So in this food chain, the wolf is at the top.
Now depending on the amount of detail you want to include in your food chain, it
could become very complex and long.
Try to think of a habitat and how the living things are connected to each other
through the food chain.
Well, birds of prey are at the top of their food chain.
Very few things eat adult birds of prey.
Another way to describe an animal at the top of the food chain is to call it an
apex predator.
Apex means the top or the highest part of something.
For example, you could say he climbed to the apex of the mountain.
That means he went to the highest point on the mountain.
It can also be used to describe the highest point in someone's life or career.
For example, he reached the apex of his career by age 35.
That means that he was at the most successful point of his career by the time he
was 35 years old.
And in our lesson, you could say that birds of prey are apex predators because
they are at the top of the food chain.
And this is important because if you have a healthy population of these birds,
that means that the rest of the habitat should also be healthy.
If there's something wrong with the animals at the bottom of the food chain, it
will affect the health and numbers of the top of the food chain.
That's right.
Well, we have a lot more to learn about these birdsright after this.