Omnivory

Omnivory is the consumption of resources from more than one trophic level by a single species. An omnivore feeds on both plants and animals, or on prey and detritus, or on primary producers and herbivores. Omnivory blurs the clean stratification of the trophic pyramid and introduces feedback loops that can either stabilize or destabilize food web dynamics. High omnivory increases connectance and can provide trophic redundancy — alternative pathways for energy flow when one prey species declines. But omnivory also complicates predictions: a species that preys on both herbivores and plants can produce counterintuitive population dynamics, including the possibility that increasing predator density decreases plant damage. The study of omnivory is essentially the study of why real ecosystems refuse to behave like textbook food chains.