The issue of population cycles in mammals is reviewed and focused on the particular case of the snowshoe hare spatiotemporal dynamics[ We have tested some hypotheses by means of an individual!oriented simulation.The results suggest that a lagged response to food supply is able to generate cycles\ which can be qualitatively very similar to the observed _eld ~uctuations[ Surprisingly spatial structures\ as target patterns and spiral waves\ emerge from the trophic interactions despite the random rules in the simulation[ These macroscopic patterns can explain the observed synchronization in hare dynamics over large areas\ which has been recently reported[ Furthermore\ the formation of spiral waves can explain the U!shape pattern in the synchronization vs[ distance plot observed by Ranta and co!workers[ Population cycles and spatial patterns go together[ An increase in the maximum vegetation available acts as a bifurcation parameter\ inducing cycles when it is up to a given thresholdSome {{simulation experiments|| are performed\ and the results are discussed in the light of _eld observations and theoretical predictions[

Peer reviewed