Lesson video

Welcome to this fifth lesson in the unit Biodiversity.

My name's Mr. Jarvis and I'm gonna be teaching you today.

Today's lesson is all about animals and how they're adapted for their environment.

By the end of today's lesson, you should be able to describe how some animals are adapted to survive and how environmental conditions can affect animal biodiversity both positively and negatively.

There are four key words to today's lesson.

They are biodiversity, adaptation, extinction, and conservation.

Here's what those words mean.

You can pause the video if you want to at this point so that you can read through those definitions, but don't worry because we will go through those definitions as we pass through the lesson.

Today's lesson is broken down into two parts.

First, we'll look at adaptations of animals, and then we'll move on to look at the impact of a changing habitat.

So, if you're ready, let's get started with our first section, which is all about adaptations of animals.

Animals, including humans, are consumers.

They rely on producers for food.

And remember, producers make their own food.

They don't just make food for themselves.

They make food for the whole of the food chain.

Here we have two pictures.

One animal, a consumer, is eating a producer, bamboo.

Another animal, a thrush, is consuming another animal, another consumer, a worm.

Plants play a really important role in the biodiversity of a habitat, but it's not just the food that the plants provide animals with.

Plants provide animals with shelter and places to reproduce.

Look at the pictures of the four habitats on the screen.

We've got a tropical rainforest, meadow, producers in the coastal seas and desert plants.

Just think, how do plants affect which animals are able to survive in a habitat? I'll pause for a few seconds to let you think.

You might have thought about those things that are already mentioned on the slide.

The fact that the plants provide the food, the shelter, and the places to reproduce.

So animals need adaptations to survive in the habitats that the plants provide them with.

Well done if you thought of any of those.

In order to live in habitats, animals need adaptations.

Remember, adaptations are features which help an organism to survive.

There are two main types of adaptations that animals have.

The first are physical adaptations.

Examples of this include thick fur, large feet, and features that help organisms to find and eat food or avoid being eaten.

A camel hoof is an example of a physical adaptation.

The hoof has a large area which spreads out the mass of the camel and stops it from sinking in the sand as it walks across the sand dunes.

The second type of adaptations are behavioural adaptations.

These are the ways that organisms behave, and examples of this include being nocturnal, migration and hibernation.

So let's look at some different types of adaptations that we see in animals.

First of all, let's look at living in hot and cold habitats.

Polar bears live in the arctic.

They're predators, and you can see in the picture the polar bear walking across the icy wastes of the Arctic habitat.

Camels live in the desert.

They feed on producers, many of which protect themselves from being eaten with large pointy spines.

What adaptations do the polar bear and the camel have that help 'em to survive in their habitats? I'll pause to let you have a think, but then we'll go through some of the answers on the next couple of slides.

Polar bears have adaptations that help them to live in the cold arctic.

Let's look at some of them.

They have small ears that help to reduce heat loss.

Fur is white, which helps with camouflage, and that helps the polar bear to creep up on its prey.

They have thick coats and fat layers underneath their skin to help them to keep warm in the really cold temperatures.

Their fur's greasy.

That helps it to dry quickly when the polar bear's been in the water.

Pads on the bottom of the feet help to provide insulation as they walk on the ice, and also help to give grip, and sharp claws and teeth help the polar bear to catch, grip and eat its prey.

Well done if you got all or any of those.

You may even have thought of some for yourself.

Many people think that a camel's hump is filled with water, but actually it's not.

It's fat.

Fat can be made into water though, through the process of cellular respiration, and that means that camels can go for long periods of time without having to have to drink water.

Their fur helps them with camouflage.

They have a thin coat of fur and that helps them to keep cool in the hot desert days, but it's also thick enough to help the camel to stay warm when it gets cold at night.

The hooves, as we've seen already in the lesson, are wide and help to prevent the camel from sinking into the sand.

Long eyelashes help to keep sand out of the eyes.

They also help to shade the eyes from the bright desert sun.

And finally, they have teeth and thick lips that help the the camel to eat thorny plants.

Well done again, if you've got any or all of those answers correct.

So here's a check.

Which of the following is not a way camels are adapted to live in their habitat? Is it A, long eyelashes to keep small grains out of their eyes? B, small ears to reduce heat loss or C, wide hooves to prevent sinking? Remember, you're looking for the answer which is not a way that camels are adapted to live in their habitat.

I'll give you five seconds and then we'll check your answer.

The correct answer is small ears to reduce heat loss.

Well done if you got that right.

Let's look at another example of a physical adaptation.

Let's look at protection from predators.

There's lots of adaptations that animals have that help to protect themselves from being eaten by predators.

Here are some of the common ones.

First of all, camouflage.

Camouflage is being hidden in the surroundings.

It's matching the backgrounds of your surroundings.

And so here in the picture, are two deer that are camouflaged.

How many deer can you see? Being camouflaged means that it's not easy for predators to spot its prey, and therefore that gives protection from being eaten.

Another common strategy and adaptation used by animals is having large sharp spines.

Here we have a sea urchin that lives in the sea.

That sea urchin is protected by having long pointy sharp spines, and that makes it a really difficult meal for predators to eat.

Another strategy used by animals is to be brightly coloured.

They advertise themselves.

This poison dart frog is saying, "Here I am, look at me, but if you eat me, it won't be a very tasty meal." Those bright colours of yellow, red, orange, and sometimes black and white tell a predator that the organism isn't gonna be a really nice meal to eat.

And another strategy used is one to startle predators.

That's seen in some butterflies.

Here's a peacock butterfly, and it has really big eye spots.

They're hidden, as the butterfly sits on a flower.

But if a predator comes along, it opens its wings and there are two big, bright eyes that actually startle the predator and try and scare it away.

Predators also use camouflage.

Look at this owl in the tree.

The owl is using camouflage so that it can get as close to its prey as possible without being seen.

Claws, talons, beaks and teeth are all really important tools for animals that are predators.

You can see in the picture that the tools that these animals have help them to catch their prey and then eat it.

Speed and surprise are another set of adaptations that animals use to catch prey.

The chameleon in the picture has a tongue that it can shoot out several centimetres from its body.

It also has a sticky pad on the end so that when it makes contact with the the prey that it's trying to eat, it sticks to the prey and allows it to recoil and pull it towards its mouth.

And finally, having really good eyesight if you are a predator, is really important.

That's particularly the case if you need to jump and catch your prey.

This tiger has good eyesight.

You can see that by the fact that the eyes are at the front of the face and pointing forwards.

Prey tend to have their eyes on the side of their head, which gives them a wider field of view.

Another example of physical adaptations are around helping to feed.

When you feed on a particular type of food, you have to have the right tools to do the job.

Here are some examples.

So hummingbirds have really long, thin beaks.

They're a bit like a drinking straw.

The hummingbird feeds on nectar, and nectar's found deep in flowers.

So the hummingbird hovers by the flower, sticks its beak deep into the flower and then uses its beak to suck up the nectar from the base of the flower.

That's its meal.

Organisms also need to have the right tools to find their food.

And so here are two examples of animals that have really good senses of smell.

The catfish has special organs in the nose that help it to detect food from a long distance away underwater.

And the kiwi is a ground nesting bird from New Zealand.

It's the only bird to have nostrils right at the end of its beak, and that means it can poke around in the leaves on the ground and find the next insect for its meal.

Spiders are able to produce silk and threads.

They attach these between branches and construct really intricate spider's webs.

The spider's webs act as a trap.

Insects flying by get caught in the web, which is also sticky.

The spiders then can go and eat their meal or wrap the body up in silk and save it for a later date.

There are many other types of physical adaptations that we see in animals.

Here are just three more.

The Turkey vulture deters predators by being sick when it's approached.

And that sick, that vomit is really smelly and that puts any predators off coming too close.

Smells are also used by other organisms. Cuttlefish distract their predators if they're going to be eaten.

They're able to produce an ink.

And so if they see something that they think is dangerous, they squirt out some ink, which actually allows them to just disappear without being noticed.

It's a bit like a magician disappearing in a cloud of smoke.

And the wallaby and other marsupials, such as the koala and duck-billed platypus are able to look after their young in pouches that they have.

These are special adaptations that help to look after their young.

Now it's time for a check.

I'd like you to match the physical adaptations with how they help the animal to survive.

So look at the pictures, A, B, C, and D and match those pictures with how the adaptation helps the animal to survive.

You'll probably need to pause the video at this point, but when you're ready, just press play and then we can check to see how well you've done.

So how did you do? What have you come up with? Let's see whether your answers are right.

So which of the pictures, A, B, C, or D prevents being seen by predators? The answer is B.

The crab is camouflaged and that prevents it from being seen by predators.

Which adaptation helps to stop sinking into the ground? The answer is A.

The large elephant foot spreads over a large area and that stops the foot from sinking into the mud.

Which picture is a warning that it may taste nasty? The answer here is D.

The butterfly is brightly coloured and advertising itself, and so the chances are that it might not make a tasty meal.

And finally, which picture is about helping to tear and eat meat? The answer is C.

The bird of prey's beak is specially adapted to help it rip flesh from the prey that it catches.

Well done if you got those right.

So now we're going to look at some behavioural adaptations.

And the first of these is being nocturnal.

Being nocturnal means that you are active at night.

So why are organisms active at night? Well, it first of all helps them to avoid being detected by predators as they search for food and water.

It helps them to avoid competition for that food and water.

If they're going to to eat or drink in a particular place, that place might be busier during the daytime.

Many organisms that are nocturnal do so because they avoid the heat of the day in hot climates, and it also helps organisms to conserve water.

And many animals that are nocturnal tend to have excellent eyesight, hearing and smell.

The second behavioural adaptation is migration.

And migration is where organisms escape winter by travelling to warmer countries.

Birds, such as swallows, spend the summer in the UK before they migrate South to Africa.

They do that because it's colder here in the UK in winter, and there's less food for them to eat.

By travelling to Africa, the climate is much warmer and there are lots of insects for them to eat over winter before they then return back to the UK in the springtime.

Geese and swans also tend to migrate in the winter.

Many of these come from the colder north in the summer, so they spend the summertime in Greenland and Svalbard.

And then in the wintertime, when the weather gets really cold in those areas, they move to a much warmer UK.

The third and final behavioural adaptation that we're going to look at today is hibernation.

Hibernation is when organisms are dormant during cold winter months.

These organisms have to eat lots during the end of the summer so that they build up lots of fat in their body, and they use this fat to give them the food that they need to keep their bodies alive during those cold winter months.

And during this time, there's often not much food around for them anyway.

Animals that hibernate in the UK include door mice, hedgehogs, bats, frogs, and insects.

During hibernation, organisms can die because of predation or because of really extreme cold weather.

Now it's time for a check on that last section of learning.

True or false? Migration is when organisms are dormant in cold winter months.

Is it true or false? And then justify your answer.

Is it because hibernation is when organisms are dormant in cold winter months, or nocturnal organisms are dormant in cold winter months.

I'll give you five seconds and then we'll come back and check your answer.

The answer is false.

And the reason is that hibernation is when organisms are dormant in cold winter months.

Well done if you got that right.

So now let's do a practise.

House martins are a bird that spend the summer in the UK.

They feed on insects.

In the late autumn, these birds fly to Africa, and here's a map that shows the journey that they take.

You can see the UK in green at the top of the arrow and Africa in yellow at the bottom of the arrow.

That's the journey that the house martins take.

I'd like you to explain why the house martins make this journey.

You'll need to pause the video, write down your answer, and then when you've finished, start the the video again and we'll check to see how well you did.

Good luck.

So the house martins migrate in late autumn when the weather begins to get colder.

This is a time when the food that they eat, which is insects, starts to decline and they travel South where the weather is warmer and where there's more insects for them to eat.

Well done if you got that right.

That brings us to the second part of today's lesson, which is all about the impact of a changing habitat.

So if you're ready, let's carry on.

Biodiversity helps maintain a healthy planet, but despite this, many human actions have destroyed biodiversity.

Humans have changed and destroyed habitats for activities such as mining, grazing, crop production, and deforestation.

When habitats and producers within those habitats are destroyed, there's a massive impact on the animals that live there.

And the destruction of habitats can lead to the extinction of animals and other organisms. When an organism becomes extinct, the species is lost forever.

And one of the most famous examples of a set of organisms that were lost forever are the dinosaurs.

Human activities on the planet have contributed to climate change, and climate change is causing weather patterns and temperatures to change in habitats.

These changes have an impact on the biodiversity of the habitats.

So for example, climate change is melting ice at the poles and wildfires destroy habitats and mean that animals haven't got food to eat.

Other human activities can lead to animals becoming endangered or extinct, and the activities include hunting animals for food.

For example, the green sea turtle.

For medicine, for example, the seahorse, which is used for medicines in some cultures.

Or as trophies.

Elephants are endangered because they've been hunted for the ivory in their tusks and their meat.

Let's do a check.

Humans have caused some animals to become extinct through deforestation.

Is that true or false? And then justify your answer.

Is it A, deforestation destroys habitats and reduces biodiversity, or is it B, deforestation destroys habitats and increases biodiversity? I'll give you five seconds to work out your answer and then we'll check to see how well you've done.

Let's check.

See how well you did.

So the answer to humans have caused some animals to become extinct through deforestation is true.

And the reason for it is that deforestation destroys habitats and reduces biodiversity.

It reduces the range of species that are found within the habitat.

Human exploration and introduction of new species to habitats have caused some animals to become endangered or extinct too.

Here's one example.

The dodo lived or was native to Mauritius.

Sailors arrived and hunted the flightless bird for food.

The sailors also brought rats and other animals with them on their ships, and those animals made it to the land.

The rats ate the bird's eggs and other animals competed for the same food as the dodo.

And it's thought that the dodo became extinct in the 1660s.

That was less than 100 years after sailors had initially arrived.

So you can see there's a huge impact that humans can have on an environment if it's disrupted and if it's changed.

Humans can, however, help to maintain biodiversity through conservation activities.

Conservation is about protecting biodiversity and the environment.

And examples of conservation work include protecting existing habitats through things like nature reserves and conservation areas.

Through managing habitats and through restoring habitats through, for example, reforestation, planting new trees and new forests.

Humans can also help animal conservation through breeding and conservation programmes in zoos.

Zoos can use visitor income to fund things like breeding programmes to help protect and maintain habitats in the natural world, and to pay for security to avoid endangered animals being hunted in protected habitats in the wild.

Let's check to see what you've understood in that last section.

So a zoo has recently housed some giant pandas.

The zoo wants to breed these pandas and protect areas of their habitat in Asia.

Why is this an example of conservation? Is it A, a breeding programme aims to increase the panda population? Is it B, the pandas can relax in the safe space of the zoo? Is it C, the pandas are well looked after and any illnesses can be treated by vets in the zoo, or is it D, protecting the panda habitat will also protect other species that live in that habitat.

So I'll give you five seconds to work out what your answer is and then we'll check.

So the answer to the question is A and D.

It's an example of conservation, because the breeding programme aims to increase the panda population.

It's maintaining the numbers of the population.

And it's D, because it's protecting the panda habitat, and that will also protect other species and maintain biodiversity within that habitat.

Well done if you got both of those answers.

So now let's move on to a practise task.

Over the past 50 years, fields have become bigger, and these have helped farmers grow more crops.

In making fields bigger, hedge rows have been destroyed.

In the countryside, hedgehog populations are declining.

Explain why the population of hedgehogs in the countryside might be declining, and secondly, how humans could help to conserve hedgehogs in the countryside.

You'll need to pause the video at this point.

Write down your answers, and then we'll check them and see how well you've done.

Good luck.

Let's check those answers.

So first of all, you were asked to explain why populations of hedgehogs in the countryside might be declining.

Here are some possible answers.

Hedgehogs live in the hedgerows around the fields.

As farmers make fields bigger by removing the hedgerows, the hedgehogs' habitat is destroyed, and there are bigger distances between hedge rows that contain the food and shelter that hedgehogs need.

Well done if you got those right.

The second question was to explain how humans can help conserve hedgehogs in the countryside.

Here are some of the answers that you might have included.

Planting and managing new hedgerows to provide habitats that the hedgehog need.

Provide protected areas and hedgehog shelters that provide habitats for hedgehogs, and that could include areas within gardens.

And providing corridors that help hedgehogs and other animals to move between their habitats.

Well done if you got any of those right.

That brings us to the last part of the lesson, which is the summary of what we've covered.

During today's lesson, we've seen that biodiversity is a measure of the range of different species that live in a place.

We've seen that animals have lots of different adaptations which help them to survive in their habitat.

Those adaptations can be physical adaptations which help them to hunt and avoid predators and behavioural adaptations, such as hibernation, migration and being nocturnal.

We've also looked at how changes to the environment can impact animal biodiversity.

Habitat loss, and human activities such as hunting can cause the extinction of species.

And we've seen that conservation of habitats and conservation work by zoos can help maintain animal biodiversity.

I hope that you've enjoyed learning about animal adaptations today.

It's been great teaching you, and I look forward to seeing you all again soon.

Bye for now.