Grass
Herbivore
Carnivore
0
Grass
0
Herbivores
0
Carnivores
0.04
12
20
Herbivores gain energy by eating grass; carnivores gain energy by eating herbivores. Each step, all agents spend metabolic energy and may die. When energy exceeds the reproduction threshold, an agent splits into two. Small parameter changes produce phase-lagged oscillations, crashes, and recoveries.