We investigate the dynamics of stage II retinal waves via a dynamical system, grounded on biophysics, and analysed with bifurcation theory. We show how the nonlinear cells coupling and bifurcation structure explain how waves start, propagate, interact and stop. Especially, we analyse how the existence of a small region in parameter space, where dynamics returns in a recurrent way, gives rise to a very rich dynamics. In this context, we propose a non linear transport equation characterizing the waves propagation and interaction.