Present address: McMaster University, Department of Biology (Theoretical Biology Lab), Hamilton ON Canada
OPTIMAL LIFE-HISTORY STRATEGIES IN SEASONAL CONSUMER-RESOURCE DYNAMICS
Article first published online: 12 JUL 2011
© 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Volume 65, Issue 11, pages 3113–3125, November 2011
How to Cite
Akhmetzhanov, A. R., Grognard, F. and Mailleret, L. (2011), OPTIMAL LIFE-HISTORY STRATEGIES IN SEASONAL CONSUMER-RESOURCE DYNAMICS. Evolution, 65: 3113–3125. doi: 10.1111/j.1558-5646.2011.01381.x
- Issue published online: 24 OCT 2011
- Article first published online: 12 JUL 2011
- Accepted manuscript online: 7 JUN 2011 07:51AM EST
- Received December 1, 2010, Accepted May 27, 2011
- Foraging-reproduction trade-off;
- individual behavior;
- population dynamics;
- semi-discrete model
The interplay between individual adaptive life histories and populations dynamics is an important issue in ecology. In this context, we considered a seasonal consumer-resource model with nonoverlapping generations. We focused on the consumers decision-making process through which they maximize their reproductive output via a differential investment into foraging for resources or reproducing. Our model takes a semi-discrete form, and is composed of a continuous time within-season part, similar to a dynamic model of energy allocation, and of a discrete time part, depicting the between seasons reproduction and mortality processes. We showed that the optimal foraging-reproduction strategies of the consumers may be “determinate” or “indeterminate” depending on the season length. More surprisingly, it depended on the consumers population density as well, with large densities promoting indeterminacy. A bifurcation analysis showed that the long-term dynamics produced by this model were quite rich, ranging from both populations’ extinction, coexistence at some season-to-season equilibrium or on (quasi)-periodic motions, to initial condition-dependent dynamics. Interestingly, we observed that any long-term sustainable situation corresponds to indeterminate consumers’ strategies. Finally, a comparison with a model involving typical nonoptimal consumers highlighted the stabilizing effects of the optimal life histories of the consumers.