Biology · KS3 Y9 · Ecosystems
Predator–prey cycles
Predator–prey cyclesFree5:05Heddy Score 3 of 7, below the standard
What you need to know
- When there is plenty of prey, predators find food easily and their numbers rise.
- As predators increase they eat more prey, so the prey population falls.
- With less food, the predator population then falls, which lets the prey population recover.
- This repeating pattern is a predator-prey cycle, with changes in predator numbers lagging behind changes in prey numbers.
- Real data for snowshoe hares and Canadian lynx over about 100 years show this cycle.
In this clip
Runs 5:05, from 0:00 to 5:05 of the full video.
Heddy ScoreSeven checks every clip must pass before students see it: trusted, on the map, accurate, focused, accessible, safe, and proven by students.3/7, Below the standard
See the seven stars
- Trusted source · passed. The creator's own upload, live and playable here.
- On the map · not judged yet. A teacher watched it: it mainly teaches this map topic.
- Spec-true · not judged yet. Accurate, and right for the current UK specification.
- Focused · passed. One idea, short enough to watch in one go.
- Accessible · passed. Good captions, clear sound and pictures.
- Safe for children · not judged yet. Right for 11 to 16 year olds, with no sales pitch.
- Proven · not judged yet. Earned from our students: they learn from it, find it helpful and watch it to the end.
Our students
Not enough students yet
Our own students' answers. These are what move ★7 Proven.On YouTube
How the Heddy Score works246K views · 1.15K likes · Khan Academy 9.5M subscribers
As reported by YouTube on 2026-11-02. Not part of the Heddy Score.Why we picked it
Talks through the logic of a predator-prey graph step by step and then checks it against the classic hare and lynx data.
Khan Academy on YouTubechecked 2026-10-22
Plays from youtube-nocookie.com. No YouTube cookies until you press play.