Feeding Relationships

• A food chain shows a simple feeding relationship.

Sun →

• All food chains start with the sun

Feeding Relationships

• A food chain shows a simple feeding relationship.

Sun → grass →

Feeding Relationships

• A food chain shows a simple feeding relationship.

Sun → grass → rabbit →

Feeding Relationships

• A food chain shows a simple feeding relationship.

Sun → grass → rabbit → fox

All food chains start with ENERGY from the sun

carbon dioxide from the air

energy from sunlight (or light)

water fromthe roots

foodtransported to therest of the plant

carbon dioxide from the air

energy from sunlight (or light)

water fromthe roots

foodtransported to therest of the plant

Photosynthesis

Because plants produce their own food, they are called ‘Producers’

The energy is then passed on to animals when they eat the plant.

Animals of all shapes…

…and sizes!

Because these animalsare the first to takethe food energyfrom the plants,

They are called primary consumers

Some of these primary consumers have predators. Other animals that feed on them

Aphids are eaten by….

Ladybirds

Animals that eat primary consumers are called secondary consumers

• So far this is a straightforward food chain

• Sun → aphid → ladybird

But in reality it is more complicated than that

This bird eats ladybirds and

aphids

This bird eats smaller birds, mice, and

rabbits

Mice and rabbits have other predators

What will eat the frog?

What do you think the frog

eats?

Sometimes it’s not entirely clear who

eats who!

We can show what goes on with the help of a Food Web

What would happen if a disease killed off many of the hawks?

There will be nothing to eat the snakes, so their numbers will

increase.

All the frogs get eaten

No frogs.

More crickets

Most of the cattail gets eaten by the

crickets

Now the crickets don’t have enough

food so their numbers go down

..and so on. Numbers of each species have an effect on the numbers of the other species in the web.

• Use the food web worksheet to predict what might happen in the following situations:

• A) There is very little rain and much of the Marsh Grass and Cattail die off.

• B) Humans nearby bring cats into the area.

• C) The frogs eats some poisoned slugs from a garden

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