Mammalian cycles: internally defined periods and interaction-driven amplitudes

Area of Science:

• Ecology
• Population Dynamics
• Mammalian Biology

Background:

• Mammalian population cycles, characterized by predictable fluctuations, have been studied for over a century.
• The causes of these cycles remain debated, with primary hypotheses focusing on predation or intra-species mechanisms.

Purpose of the Study:

• To unify existing hypotheses explaining the period and amplitude of mammalian population cycles.
• To propose a novel theoretical framework integrating maternal effects and predator abundance for cycle causation.

Main Methods:

• Integration of the eigenperiod hypothesis (maternal effects) with a predator-prey model for cycle amplitude.
• Application of the unified theory to snowshoe hare population dynamics in northwestern North America.

Main Results:

• The study successfully unites distinct mechanisms for cycle period (eigenperiod hypothesis) and amplitude (predator abundance).
• A unified theory provides a consistent explanation for the causation of mammalian cycles.

Conclusions:

• The developed theory offers a comprehensive understanding of mammalian population cycle dynamics.
• A forecast indicates the next snowshoe hare cycle (peaking in 2016) is predicted to exhibit an exceptionally low amplitude.