How animals endure by bending environmental space: Redefining the fundamental niche

Abstract

For 70 years, the fundamental niche, the complete set of environments that allow an individual, population, or species to persist, has shaped ecological thinking. Yet, its properties have eluded quantification, particularly for mobile, cognitively complex organisms. Here, I derive a concise mathematical equation for the fundamental niche and fit it to population growth and distribution data. I find that, within traditionally defined environmental spaces, habitat heterogeneity and behavioural plasticity make the fundamental niche more complex and malleable, but also more predictable, than previously envisaged. This important re-evaluation restores the fundamental niche as a cornerstone of ecological theory and promotes it as a central tool for applied ecology. It quantifies how organisms buffer themselves from change by bending the boundaries of viable environmental space, and offers a framework for designing optimal habitat interventions to protect biodiversity or obstruct invasive species.