  In this work, the time-dependent solution for the Lotka-Volterra
Predator-Prey model is derived with the help of the Lambert W function. This
allows an exact analytical expression for the period of the associated
limit-cycle oscillations (LCO), and also for the response time between predator
and prey population. These results are applied to the predator-prey interaction
of zonal density corrugations and turbulent particle flux in gyrokinetic
simulations of collisionless trapped-electron model (CTEM) turbulence. In the
turbulence simulations, the response time is shown to increase when approaching
the linear threshold, and the same trend is observed in the Lotka-Volterra
model.
