A compilation of my problems I ran into when I was fiddling around in order to make the foxes and bunnies act differently than the sheep and wolves. I wanted to make the bunnies be able to reproduce faster than the sheep and the foxes to move slower than the wolves.
This lead to the bottom right image where the rabbits reproduced way too quickly and I had forgotten to decrease the max amount of rabbits. That shot was taken about 5 seconds before the program shut down my laptop.
These are screenshots from my successful project, the only way I found that even came close to a balanced ecosystem was to boost the weeds growth to a heightened level, begin with a small amount of rabbits, and to increase the amount of energy gained by the foxes when they ate a rabbit.