ScienceWildlife watching like a scientist35 min★★ difficulty

Food webs in a British woodland

An oak tree can feed over two thousand species. This lesson follows the energy through a British woodland — from leaf to caterpillar to blue tit to sparrowhawk — and shows what happens when one thread is cut.

Lesson overview

What you'll learn in this lesson

Understand the interdependence of organisms in an ecosystem, including food webs and insect pollinated crops

Key learning points

• One tree, thousands of diners
• Chains join into webs
• The energy shrinks as it climbs
• When a thread is cut

This lesson at a glance

35 minutes
19 parts to scroll through
4 quick checks
Marked quiz at the end
Gentle pace: short sittings with pauses

Words to know

interdependenceorganismsecosysteminsectpollinated

Scroll down — the lesson carries on below

Part 1 of 19 · Discover5%

Watch & discover

Part 1 of 19

Watch first

Food webs in a British woodland

An English teaching video on this topic from Fancy Scientist. Watch it, then scroll down for the lesson.

In a nutshell

Understand the interdependence of organisms in an ecosystem, including food webs and insect pollinated crops

What you already know

Part 2 of 19

Before we start

What you already know

You know plants are producers and that animals eat plants or other animals.

Recap: How a leaf eats sunlight

Key words

Part 3 of 19

Key words

Words you'll need today

producer: An organism that makes its own food — the start of every chain.
apex predator: The hunter at the top with no natural predators of its own.
interdependence: Species depending on each other for food, shelter or pollination.

Learning cycle

Part 4 of 19

Learning cycle 1 of 2

Part 1 — Following the energy

A short piece of teaching, then a check to make sure it has landed.

Explore the idea

Part 5 of 19

Learn

One tree, thousands of diners

Oak leaves feed caterpillars, moths and beetles; the acorns feed jays, squirrels and wood mice; the dead wood feeds fungi and stag beetle larvae; the holes in old oaks house owls and bats. A single ancient oak is less a plant than a tower block with a canteen.

Explore the idea

Part 6 of 19

Learn

Chains join into webs

Oak → caterpillar → blue tit → sparrowhawk is one chain, but the blue tit also eats spiders and aphids, the sparrowhawk also takes blackbirds, and the caterpillar is hunted by wasps. Draw every connection and you get a web — which is why losing one species rarely kills just one chain.

Quick check

Part 7 of 19

Quick check

In oak → caterpillar → blue tit → sparrowhawk, the producer is...

Quick check

Part 8 of 19

Quick check

Roughly how much energy passes from one level to the next?

Reset break

Part 9 of 19

Pause

That's sitting 1 of 2 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now

Learning cycle

Part 10 of 19

Learning cycle 2 of 2

Part 2 — Pulling the threads

A short piece of teaching, then a check to make sure it has landed.

Explore the idea

Part 11 of 19

Learn

The energy shrinks as it climbs

Only about a tenth of the energy at one level reaches the next — the rest is lost as heat, movement and waste. That is why there are millions of caterpillars, thousands of blue tits and a handful of sparrowhawks, and why big predators need big territories.

Explore the idea

Part 12 of 19

Learn

When a thread is cut

When grey squirrels arrived from America, they out-competed reds for food and carried a pox deadly to reds but harmless to themselves. Red squirrels now survive mainly where greys are absent. One introduced species rewired the whole woodland web — a lesson in how connected everything is.

Quick check

Part 13 of 19

Quick check

A food web is more realistic than a chain because...

Quick check

Part 14 of 19

Quick check

Red squirrels declined mainly because greys...

Investigate evidence

Part 15 of 19

Evidence 1 of 1

primary

A woodland food web survey

Woodland Trust citizen science survey, Ecology field study

Oak tree: one mature tree supported 284 insect species in the survey. Caterpillars peaked in May; blue tit nests with chicks peaked two weeks later; sparrowhawk sightings clustered within 200 m of the tit nests.

Real food webs are measured by counting who eats whom over a season. Timing matters: predators raise their young exactly when prey is most abundant.

Think like a historian

Use the survey to draw the chain from oak leaf to sparrowhawk. What would happen to the blue tits if a late frost killed the May caterpillar peak?

Source: Citizen science survey data collected in British broadleaf woodland.

View the archive record ↗

Common mix-ups

Part 16 of 19

Common mix-ups

Things people often get wrong

Drawing a food chain and thinking that is the whole story — real feeding is a web.
Thinking energy is recycled like nutrients — it flows through and is lost as heat.
Assuming top predators are the most numerous — they are the rarest.

Challenge round

Part 17 of 19

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

Mastery quiz

Part 18 of 19

Marked quiz

End of lesson quiz: Food webs in a British woodland

3 questions, marked with the reasoning shown. No timer.

1. An apex predator is...
2. Why are sparrowhawks rarer than blue tits?
3. Interdependence means...

Lesson round-up

Part 19 of 19

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

Points this lesson

Best run

0 in a row

Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Why the school greenhouse failed

A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.

The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.

The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.

Written for Good Learning Co.

Reading questions

Name the variable the club changed the second time, and one variable they kept the same.
Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
Write a conclusion for the club's report, saying how far the evidence supports it.

Source for this lesson

Use this for the source work task below.

A woodland food web survey

primary

Woodland Trust citizen science survey, Ecology field study

Oak tree: one mature tree supported 284 insect species in the survey. Caterpillars peaked in May; blue tit nests with chicks peaked two weeks later; sparrowhawk sightings clustered within 200 m of the tit nests.

Real food webs are measured by counting who eats whom over a season. Timing matters: predators raise their young exactly when prey is most abundant.

Source: Citizen science survey data collected in British broadleaf woodland.

View the original record ↗

Method and results
Writing
Write the aim, what you changed, what you measured and what you kept the same, then record your results in a table.
1 page + results table
Conclusion
Writing
Explain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.
6–8 sentences
Labelled diagram
Diagram
Draw the apparatus or the process in pencil, label it fully, and photograph it.
1 labelled diagram
Reading and notes
Reading
Read the lesson text again and write the key ideas in your own words.
Half a page of notes

Write your answer, notes or working here

Saved as you type.

Photos of paper work, diagrams or working outHow many minutes did the written work take?

Part 1 of 19 · Watch & discover

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