Lesson video

Welcome to today's lesson.

This is lesson three in the unit ecosystems and it's all about adaptations of predators and prey.

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

By the end of today's lesson, you should be able to describe how predators and prey are adapted to help them survive.

We're gonna use four key words during today's lesson.

These are adaptation, camouflage, prey, and predator.

The definitions of these words are coming up on the screen now.

Have a read through them for yourself, but don't worry, we'll be talking about them during the course of the lesson and explaining what each of the words mean.

But if you need more time to read through those words, please pause the video.

There are three parts to today's lesson.

First of all, we're going to look at types of adaptation.

Then we're going to look at the adaptations that organisms have to avoid predators.

And finally, we're going to look at adaptations that help predators to catch their prey.

So if you're ready, let's get started with types of adaptation.

All living things have features that help them to survive in the places that they live, and those features are known as adaptations.

There are two main types of adaptations that organisms have.

First of all, there are adaptations that help organisms to feed like this bear claw.

The second type of adaptation is for protection.

So the tortoise has a shell on its back that it can withdraw its soft, fleshy body into if it's attacked by a predator.

Polar bears live in the arctic.

Temperatures there are really low.

You can see in the picture the ice that the polar bear is living on.

What adaptations does the polar bear have to help it feed and give it protection? I'll pause for five seconds while you think about some of those adaptations and then we'll check to see if you've got any of them right.

So polar bears live in really cold arctic environments.

Some of the adaptations you might have thought of that help it to survive include smaller ears and a small tail to reduce heat loss.

Having white fur, that helps it blend into the background and that's called camouflage.

That helps it to sneak up on its prey.

Has a thick coat and a fat layer to help keep it warm.

It has greasy fur to help it dry more quickly after it's been in the cold icy waters.

It has pads on the bottom of the feet, that helps to insulate the feet on the cold ground, and also the claws help the polar bear to grip.

And along with gripping, those claws and sharp teeth help the polar bear to catch, grip, and eat prey.

Well done if you've got some of those.

Here's a cactus.

A cactus is a plant and they often live in deserts.

Deserts are often really dry places where the temperature during the day is very high and the temperature at night is very low.

So what adaptations does the cactus have to help it feed and give it protection? I'll give you five seconds.

What did you come up with? We know that cacti live in deserts that can be really dry places.

We also know that deserts can be really hot in the daytime and really cold at nighttime.

So how are cacti adapted in terms of making their own food and in terms of giving themselves protection? These are some of the things that you might have come up with.

First of all, the leaves are adapted.

They're reduced to spines.

That has two advantages.

First of all, it means that the cactus loses less water, and secondly, the cactus gets protection from consumers coming along to eat it.

Secondly, the swollen stem of a cactus stores water.

This means that the cactus has some water in reserve in really long hot, dry periods.

Photosynthesis, the way that the cactus makes its own food doesn't take place in the leaves.

Instead, it takes part in the green stem.

Below the surface, there are long roots.

These tap down into deep water reserves in the soil and help the campers to draw up water into the plant.

Alongside this, there are a lot of really fine shallow roots right against the surface, and this helps the cactus to catch any light rain that might fall or even dew at night that might form on the surface.

The cactus is adapted to grabbing as much water as it can from the surface of the soil.

Well done if you got some of all of those.

You might even thought of others for yourself.

If you did, well done.

Now we're going to check to see how much you've understood so far.

It's a true or false question, but importantly, you need to be able to give a reason for your answer.

So true or false? Adaptations are features that organisms choose to have.

Is that true or false? And is that because organisms inherit adaptations from their parents or because organisms develop adaptations depending on what they need to survive? I'll give you five seconds to think about your answer and then we'll see whether you've got it right.

So in terms of the first part, adaptations are features that organisms choose to have.

The answer to that is false.

They don't choose them, and the reason why it's false is because organisms inherit adaptations from their parents.

So organisms inherit adaptations that suit the environment and they get those from their parents.

Well done if you got both of those parts right.

So now we're gonna practise our learning.

I'd like you to describe and explain two adaptations for each example given below.

You need to use the information from the image and your own knowledge to help you.

The first example is a squirrel.

I'd like you to describe and explain two adaptations of the squirrel that enable it to feed on the nuts that grow at the top of a tree.

The second example is that I'd like you to describe and explain two adaptations that the lizard has to enable it to avoid being eaten by birds in a sandy desert.

You'll need to pause the video, write down your answers, and then when you're ready, restart the video, and we'll check to see how well you did.

Good luck.

Let's see how you did.

You were asked to write down and explain two adaptations for each of the organisms. Let's look at the squirrel example first.

You were asked to talk about the adaptations that help the squirrel to feed on the nuts that grow at the top of the tree.

Answers that you might have had include sharp claws to help the squirrel to climb and grip.

The squirrel has a large tail that helps the squirrel to balance as its climbing.

The claws also help the squirrel to grip the nuts and eat them.

And finally, the large ears that a squirrel has means that the squirrel can collect food while listening out for predators.

Well done if you've got some or all of those or if you've got any of others for yourself.

Secondly, you were asked to write down adaptations for the lizard to help it avoid being eaten by birds in a sandy desert.

Some of the answers that you might have come up with are that the lizard is the same colour as the surroundings and that helps it because it's camouflage.

The lizard has long legs and that helps it to run fast and the lizard may have good eyesight to help spot predators when they get close.

Well done if you've got any of those or others that you might have thought of for yourself.

So that brings us to the second part in today's lesson, and we're now going to be looking at adaptations that organisms have to avoid predators.

So if you're ready, let's go.

Predators are organisms that hunt and catch other animals to get the food that they need to survive.

Prey are the organisms that are hunted for food.

Prey want to avoid being eaten, and they have adaptations that help them to do this.

We're going to look at some of the adaptations that help prey to avoid being caught by predators as food.

Some of these include a wide field of vision, camouflage, warning signs, mimicry, spines and hairs, eyespots, and making chemicals and smells that deter predators.

We're going to look at these one by one, starting with eyesight.

So prey need to be able to see their predators.

And to help them do this, they often have eyes on the side of their head.

This helps because it gives them what we call a wide field of view.

The picture of the hare on the right hand side of the screen shows that the eyes are located on the side of the rabbit's head.

The skull at the bottom of the screen is looked at from above.

You can see the eyes that are on the side of the head.

Having eyes on the side of the head means that it's not great in terms of detail, what we call binocular vision.

Binocular is where we have both eyes seeing the same image.

And you can see that there's a fairly small field of view in terms of what a hare can see in front of it.

In addition, because the eyes are on the side of the head, there's a spot in front of the hare that it can't see at all.

It has a blind spot, but because the eyes are on the side of the head, what this means is that it can see a very wide field of view and there's a very small blind spot behind the head, but it's nowhere near as big a blind spot as, say, you have as a human.

The next strategy is camouflage.

Camouflage is used to help organisms to blend into their surroundings.

Some organisms such as chameleons and squid can change their colour to match the surroundings that they're in.

Others blend into their surroundings and it can be a result of matching the surroundings in terms of the colour or by having a pattern, and patterns help to break up the outline of an organism so that it's less easy to spot.

Here are three examples.

We have a stick insect, which is camouflage because it's looking like surroundings.

It's looking like a stick and it's really difficult to spot it.

The lizard has the same pattern, the same colour as the surroundings that it sat on.

And the giraffe in the picture is less easy to spot because it has a pattern which helps to break up its outline.

By using camouflage, organisms can hide in plain sight.

Here's an image.

How many deer are in the photo? I'll give you a couple of seconds to scan the photo and we'll see how many you spot.

So there are two deer in the photo.

There they are highlighted in the circle.

Well done if you spotted them both, but you can see how well they're camouflage.

Some organisms actually advertise where they are by being brightly coloured.

These organisms are, particularly if they're coloured bright yellow, red, or orange, are poisonous.

Black and white colours may also indicate to a predator that the organism might not be as tasty a snack as they think they are.

In the images we've got some brightly coloured organisms. We have some poison dart frogs that release toxin from their skin, burnet moths that are showing a red and black coloration.

And the bright red millipedes may not be a tasty snack for the predator as much as they seem.

Mimicry is also used by some organisms to help give them protection.

To mimic means to copy.

And so some organisms that are brightly coloured may not be quite what they seem.

This is because they copy the coloration of organisms that are more poisonous and that helps to protect them from predators.

In our first image, you can see a wasp and a hoverfly.

The wasp on the left hand side has a nasty sting that's toxic or venomous to some of its predators.

On the right hand side, you have a harmless hoverfly, but the hoverfly is coloured in the same way and that gives it some protection.

The second image are two butterflies, the monarch butterfly and the viceroy butterfly.

They're very similar in coloration, but if you look closely, there are some differences in the patterns on their wings.

Just inside the circles there you can see some differences.

The monarch butterfly is toxic to some birds that eat it.

The viceroy is harmless but is protected by the coloration that it mimics from the monarch.

There are physical features that help protect organisms too.

This makes it for predators to actually eat them.

So here are two examples, a hedgehog and a sea urchin from the seabed.

Both are really spiny and prickly and that helps to protect them from predators.

Other organisms use hair to make it more difficult for predators to eat them.

So here are examples of caterpillar with different sorts of hairs and spines that make it tricky to eat.

Eyespots are used in two ways to help avoid being eaten.

Some use of eyespots is to deflect predators.

So here are two examples.

We have the butterfly fish on the left hand side, and you can see the dark eye spot on the top right hand corner of the fin.

But actually the eye is down towards the bottom end of the picture.

You can see it towards the snout end.

The idea of that eyespot is to deflect a predator to try and eat the part that's less vulnerable.

The owl butterfly is very similar.

It looks like the head of the butterfly is where the big eyespot is.

So it's deflecting the predator away from the most vulnerable parts of the body.

Other organisms use eyespots to startle their predator.

So two examples are the peacock, which has a brightly ice spotted tail, and the peacock butterfly, which when it opens its wings, give these eyespots and startles and scares predators away.

Chemicals are used by organisms to help make them smell and taste unpleasant or to repel predators when the prey feel threatened.

The stink bug is given its name for a reason.

It stinks.

It produces a really foul smelling chemical, which puts predators off eating it.

The turkey vulture, when it's threatened, is sick.

Its vomit smells really bad and puts predators off eating it.

And wood ants produce acid.

When they're threatened as a group, they spray acid at their predator and that acid starts to irritate the skin and puts predators off eating them.

So let's check to see how well you've understood that section so far.

I'd like you to match the adaptations that a prey might have with how those adaptations help them to avoid being eaten.

The adaptations are camouflage, mimicry, eyes on the side of the head, bright coloration, and eyespots.

And how they help is to distract the predator, resemble an organism with features that a predator will avoid.

Predators can be seen from a wide field of view, warn a predator that they are poisonous or taste unpleasant, or blend into the surroundings.

You'll need to pause the video at this point while you match the adaptation with how that adaptation helps to avoid them being eaten.

When you're ready to move on, resume the video and we'll see how well you've done.

Good luck.

So let's see how you did.

Camouflage helps prey to avoid being eaten because it helps them to blend into the surroundings.

Mimicry resembles an organism with features that the predator will avoid.

Having eyes on the side of the head mean that predators can be seen from a wide field of view.

Bright coloration warns predators that they're poisonous or taste unpleasant, and eyespots distract the predator.

I hope you got them right.

So here's a chance to practise.

The photograph shows a picture of a crab on a shingle beach.

There he is.

The crab is adapted to avoid being eaten by predators.

Write a paragraph using the information from the image in your own knowledge that explains how it's adapted.

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

So the crab has adapted to avoid being eaten by predators.

The paragraph will hopefully have included some of the following points.

Firstly that the crab is well camouflaged.

It has pincers or claws to help fight off predators, has long legs so it can move quickly over the shingle, and it has a hard shell and an outer covering to protect it from being eaten.

You might have got some others, but well done if you got those ones.

That brings us to the third part of today's lesson, which is all about adaptations that help predators to catch their prey.

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

Predators also have a number of adaptations that help them to catch their prey as food, and they include having strong jaws and good eyesight, camouflage, tools for hunting such as claws, talons, and beaks, and speed.

We're gonna look at each of these one by one.

So let's start with jaws and their eyesight.

Apex predators have really sharp teeth, and these help them to kill and tear meat.

They also have big jaw muscles which help the jaws clamp down quickly to help kill their prey.

And you can see these in the skulls of the puma and the lion's teeth and jaw in the image on the left hand side.

Predators, and in particular apex predators, also have excellent eyesight.

Their eyes are located together at the front of the head, as you can see in the picture of the tiger.

And this helps them to be able to judge distance really, really well.

In the picture of the skull of the tiger, you can see the eye sockets at the front of the head, and this means that they have a really good field of binocular vision and that helps them to judge the distance that they need to judge when they're hunting and catching their prey.

They have a less good field of view than some of the prey that we've looked at, and they have a big blind spot behind the back of their head.

Camouflage is also used by predators.

It helps them to get closer to their prey, making it easier to catch a meal.

And many of the predators that use camouflage are also masters at being able to sneak up on their prey unnoticed.

Here we have three organisms, a lion, rattlesnake, and owl.

All three of them are well camouflaged into their backgrounds.

You can see that the lion matches the colour of the grass in which it lives.

But how easy is it to spot the second lion behind? The coloration is allowing it to sneak up.

The rattle snake is the same colour as the rocks in which it's sitting on, and the owl blends perfectly in with the tree, meaning that it's really difficult for prey to notice it.

Organisms that are predators have tools to help them hunt.

This is in the form of claws, talons, and beaks.

This range of tools helps predators to catch and kill their prey.

Talons and claws are curved and sharp, while beaks of birds can help them to stab fish that are swimming underwater.

And finally, speed.

Catching prey by surprise is an important part of being a predator.

And predators are often able to run fast or catch a prey off guard.

Here are some examples.

Cheetahs are able to get up to really fast speeds to chase the deer and the zebra that it might want as their next meal.

Chameleons use a really special tactic.

They have a long tongue that they can fur out a long distance to catch their next meal without getting too close.

And the praying mantis sits and stalks and then quickly attacks to catch its next meal.

Now it's time to check to see how well you understood that section.

Jacob tells you two things that help predators to catch their prey.

Which statements do you agree with and how sure are you? So statement A, arctic foxes change their coat colour during the year.

This helps them to match their surroundings.

This is called mimicry.

Is that right or wrong? How sure are you? The second sentence is predators have eyes which face forwards.

This helps them to judge distance better.

What do you think? You'll need to pause the video and then restart it when you're ready to move on.

So how did you find that? I hope that you got these right.

So arctic foxes change their coat colour during the year.

This helps them match their surroundings and is called mimicry.

That is wrong.

Mimicry means to copy another organism.

Predators have eyes which face forwards.

This helps them to judge distance better.

That's right.

Well done if you've got both of those right.

Now here's a chance to practise your learning.

Here are some pictures of parts of organisms. We have eyes of an owl, teeth of a shark, patterned fur of a cheetah, and claws of a polar bear.

All of these organisms are predators.

I'd like you to explain how each part of the predator helps it to catch its prey.

You'll need to pause the video, write down your answers, and then come back and we'll check to see how well you've done.

Good luck.

So let's see how you did.

You are asked to explain how each part of the organism helped the predator to catch its prey.

So the eyes of an owl give it good binocular vision and help it to judge distance.

The teeth of the shark are sharp and curved, and that helps them to kill and hold onto prey.

The patterned fur of a cheetah, the pattern helps to camouflage the cheetah and the predator can then get closer to the prey before it's noticed.

And the claws of a polar bear are powerful and sharp, and that helps them to kill their prey.

Well done if you got those right.

So that brings us to the end of today's lesson.

Here's a summary of what we've covered today.

We've covered that adaptations are features of organisms that help them to live in a particular place.

Some adaptations help prey to avoid predation and others help predators to catch their prey.

An example of an adaptation which both predators and prey use is camouflage.

And camouflage helps prey hide from predators and it helps predators to approach their prey unnoticed.

I hope that you've enjoyed today's lesson.

It's been good learning with you today, and I look forward to seeing you again soon.

Bye for now.