Wolves -Elk-Grass
Select initial elk, wolves, and grass.
Wolves (red) eat neighboring elk and reproduce in that space. Wolves die without elk. Elk eat grass and reproduce. Elk die without grass.
After elk increase, wolves increase briefly, but then elk decrease, then decreased wolves.
Can you find conditions supporting survival of elk & wolves ?
Predator-prey systems have surprising qualities. You might think that reducing predators would help the prey, but that’s not always true.
You will discover elk and wolves take turns rising and falling in number, and the hidden role of grass in this elk-wolf ecology. You can dive into a predator-prey system with this model of wolves and elk.
Our simplest predator-prey model may be this rock-paper-scissors model.
See more in our Scratch Ecosystems Studio
4-Way Ecosystem
The most interesting slider setting is 2 predators or more needed to beat neighboring prey.
Try setting the slider to 3: notice this can leave a few lone squares protected and stable.
Even more interesting is the 3-way ecosystem that is essentially an ecological rock-paper-scissors. For that, hit next.
