Energy Pyramids
Only about 10% of energy passes to the next trophic level.
About this topic
Energy pyramids show how energy decreases at each trophic level. Only about 10% of the energy passes to the next level; the rest is lost as heat from respiration, in movement, in waste and in uneaten parts. This is why food chains rarely exceed four or five links and why there are far fewer top predators than herbivores.
Pyramids come in three kinds. A pyramid of numbers counts organisms, a pyramid of biomass shows the dry mass at each level, and a pyramid of energy shows energy transferred per area per year. Energy pyramids are always upright, but numbers pyramids can be odd: one large tree supports thousands of insects, giving an inverted shape.
A worked example: if grass in a field captures 10 000 kJ, then about 1000 kJ reaches the rabbits, about 100 kJ reaches the foxes and only about 10 kJ reaches any animal above them. The percentage transfer is energy in the next level divided by energy in the previous level, multiplied by 100.
The 10% rule explains why eating plants directly feeds more people per hectare than raising animals for meat, a point used in discussions of food security. Students often think the energy is destroyed; in fact it is transformed and released as heat, so it obeys conservation of energy but cannot be reused by producers.
Key ideas
- Energy lost as heat
- Fewer organisms at the top
- Biomass pyramids
Quick check
Use cases: where Energy Pyramids helps
- Homework: review the key idea behind Energy Pyramids before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Energy Pyramids without notes.
- Visual learning: play with the interactive lab to see how Energy Pyramids changes when you adjust its inputs.
- Teaching a friend: explain Energy Pyramids in your own words, then compare your version with the key ideas.
Biology underpins medicine, farming, conservation and biotechnology.
Frequently asked questions
What is Energy Pyramids?
Only about 10% of energy passes to the next trophic level.
What will I learn in Energy Pyramids?
Energy lost as heat. Fewer organisms at the top. Biomass pyramids.
Is Energy Pyramids part of Biology?
Yes. It is one of 150 Biology topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Energy Pyramids lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Energy Pyramids?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.