A paper (and an introduction to the paper) in Nature this week seems to have made progress on the existence of indefinite predator-prey cyles. As in the lynx/hare dataset available on R. The paper is focusing on another pair, an invertebrate and its prey, an algae. For which the authors managed a 50 cycle sequence. What I do not get about this experiment is how the cycle can be tested via a rigorous statistical experiment.

“…the predator–prey system showed a strong tendency to return to the dominant dynamical regime with a defined phase relationship. A mathematical model suggests that stochasticity is probably responsible for the reversible shift from coherent to non-coherent oscillations, a notion that was supported by experiments with external forcing by pulsed nutrient supply.”

As I had not renewed my subscription to Nature in time, I could not check the additional material for details, but the modelling seems to involve a wavelet decomposition of the bivariate time series, with correlations between the two series…