Energy Pyramids
📖 Learn
In ecosystems, energy flows from one organism to another through feeding relationships. But here's something surprising: most energy is lost at each step! An energy pyramid helps us visualize how energy decreases as it moves through a food chain.
⚡ What is an Energy Pyramid?
An energy pyramid is a diagram that shows how much energy is available at each level of a food chain. It's shaped like a pyramid because there's always more energy at the bottom than at the top. Producers form the wide base, while top predators sit at the narrow peak.
The 10% Rule
One of the most important concepts about energy pyramids is the 10% Rule. This rule tells us that only about 10% of energy is passed from one level to the next. The other 90% is "lost" as it's used for life processes.
Where Does the "Lost" Energy Go?
The energy isn't really lost—it's just not available for the next consumer. Here's where it goes:
Movement
Animals use energy to move, run, swim, and fly. This energy becomes heat.
Body Functions
Breathing, pumping blood, digesting food—all require energy.
Body Heat
Warm-blooded animals use lots of energy to maintain body temperature.
Waste
Not all food is digested. Some energy leaves the body as waste.
🤔 Why Does This Matter?
- Fewer top predators: There's not enough energy at the top to support many large predators
- More producers needed: Ecosystems need lots of plants to support all the animals
- Food chain length: Most food chains have only 4-5 levels because there's too little energy left after that
Interactive Energy Calculator
💡 Examples
Test your understanding of energy pyramids with this challenge!
If producers have 10,000 units of energy, how much energy will primary consumers receive?
✏️ Practice
Answer these questions to check your understanding of energy pyramids.
✅ Check Your Understanding
📐 Energy Pyramid
A diagram showing energy amounts at each level, with producers at the wide base.
🔟 10% Rule
Only about 10% of energy is transferred from one level to the next.
🌿 Producers
Have the MOST energy - they capture energy directly from the sun.
🦅 Top Predators
Have the LEAST energy - they're at the top of the pyramid.
🔥 Energy "Loss"
90% of energy is used for movement, body heat, and life processes.
⛓️ Chain Length
Most food chains have 4-5 levels because energy runs out.
🎯 Key Takeaways
- Energy pyramids show how energy decreases at each trophic level
- The 10% rule: only 10% of energy passes to the next level
- Energy is used for movement, body functions, and maintaining body heat
- This is why there are always more producers than top predators in an ecosystem
🚀 Next Steps
- Draw an energy pyramid for your favorite ecosystem
- Calculate energy transfer through a 5-level food chain
- Research how much energy the sun provides to plants
- Think about how energy pyramids affect conservation efforts