Maternal effects on offspring consumption can stabilize fluctuating predator–prey systems

Abstract

Maternal effects, where the conditions experienced by mothers affect thephenotype of their offspring, are widespread in nature and have the potentialto influence population dynamics. However, they are very rarelyincluded in models of population dynamics. Here, we investigate a recentlydiscovered maternal effect, where maternal food availability affects the feedingrate of offspring so that well-fed mothers produce fast-feeding offspring.To understand how this maternal effect influences population dynamics, weexplore novel predator–prey models where the consumption rate of predatorsis modified by changes in maternal prey availability. We address the‘paradox of enrichment’, a theoretical prediction that nutrient enrichmentdestabilizes populations, leading to cycling behaviour and an increasedrisk of extinction, which has proved difficult to confirm in the wild. Ourmodels show that enriched populations can be stabilized by maternal effectson feeding rate, thus presenting an intriguing potential explanation for thegeneral absence of ‘paradox of enrichment’ behaviour in natural populations.This stabilizing influence should also reduce a population’s risk ofextinction and vulnerability to harvesting.