Applications of the Invasion Criterion to Reintroduced Large Herbivore Populations

Abstract

Species coexistence can be defined as the maintenance of biodiversity. Modern coexistence theory defines stable coexistence as one were no species in an established community experiences long-term changes in their density and unstable coexistence when there is. There are many mechanisms that stabilizing species coexistence, but they all center increasing intraspecific competition over interspecific. The invasion criterion, specifically mutual invasibility, is the strongest test for establishing that two species can coexist. In the natural world, coexistence can be found in many systems, yet one that has captivated ecologists for decades in the browser-grazer continuum that is attributed to stabilizing coexistence in large herbivore assemblages, through dietary niche partitioning. As biodiversity continues to decline worldwide, and extinction rates increase, more and more conservationist turns to species translocations as a tool for managing and restoring ecosystems. Translocations can be investigated using the invasion criterion, to many ends including predicting the potential success of translocations, understanding the potential impact an introduced species could have on the residing species, and so many more. This investigation made use of comparative methods to look at 18 pairwise comparisons across 3 protected areas in Africa to examine the possible applicability of the invasion criterion on translocated species. The results of this study are largely mixed, but it is my hope that a new avenue of investigation may have been explored. Finally. future applications of this test may be possible through the use of new ecological technologies and methodologies.