Living Meadow
A tiny made-up ecosystem. Plants regrow, herbivores graze and predators hunt them. Change one thing — how fast plants regrow, how fast herbivores move — and watch the balance shift.
Watch grazers and hunters share a small wrap-around meadow, and test how one change shifts the balance.
FreeOn this device
Darker green = more plant energy. Circles are herbivores (lighter = slower), red triangles predators. The edges wrap round.
Invented rules that illustrate trade-offs — not a forecast of any real ecosystem.
Controls
- Play runs the meadow; Step one generation advances exactly one tick; Reset replays the same seed from the start; New seed starts a different meadow.
- Preset and Experiment load starting conditions; Regrowth and Herbivore speed change them (and reset the run).
- +10 herbivores and +2 predators add animals during a run; Export CSV saves the population history.
The rules
- The meadow is 40 × 24 cells and wraps at the edges. Each cell holds plant energy from 0 to 10 and at most one animal.
- Herbivores make 1–3 moves towards the leafiest free cell and eat up to 4 energy; each tick costs them 1 energy whatever their speed. Predators take an adjacent herbivore for 12 energy and pay 2 a tick.
- Animals act in a shuffled order each tick. Above 20 energy an animal shares it equally with a newborn next to it; herbivore offspring sometimes differ in speed by one. Births and deaths happen together.
Scoring, saving and limits
No score — the chart and the counts are the result. A population that dies out stays out unless you add animals.
Your settings (including the seed) are kept on this device; the run itself restarts on reload and replays exactly the same from that seed.
Invented rules that illustrate trade-offs, not a forecast of any real ecosystem. At most 500 animals; births beyond that wait for space.
Questions
- Why do faster herbivores not always win?
- Speed helps them find food and costs nothing extra here — but grazing faster also strips the meadow faster.
- Why did the predators vanish?
- They need a herbivore next to them often enough to cover 2 energy a tick. When prey thins out, they starve first.
- Is each run different?
- Only if you change the seed. With the same seed and settings, every run is identical.