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
water from
the roots
food
transported to the
rest of the plant
energy from
sunlight
(or light)
Photosynthesis
carbon dioxide from the air
water from
the roots
food
transported to the
rest of the plant
energy from
sunlight
(or light)
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 animals
are the first to take
the food energy
from 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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