Rough Data

The predators corresponds to the fluorescent named JOE, whereas the preys are FAM. Indeed, there should always be more prey than predators after a little time (one predator needs one prey to reproduce itself).

Differential equation

Here is the result of the numerical integration of the model, with exo=1 and g=1.

Conclusion

We ran a bit out of time as we do not totally master R software. However, this primary results can still be interpreted: Many experiements were successfull, aswe see the oscillations. When there is not enough grass, the oscillations do not occurs. Moreover, when the concentration of exo rises, the period of the oscillation seems to evolve, but we do not have time to study in which way.