The Role of Biotic Interactions in the Niche Reduction Hypothesis: A Reply to Doherty and Driscoll

Abstract

The 'niche reduction hypothesis' (NRH) postulates that declining species can experience reductions in their realized niche breadth because environmental, biotic, and evolutionary processes reduce or amplify threats, or because a species' capacity to tolerate threats varies across niche space. Doherty and Driscoll embrace the NRH and then expand on one of the important biotic processes, interspecific competition, and its role both in contributing to contractions of species' realized niches and as a potential barrier to niche reoccupation. Interspecific competition is indeed important in some species declines. However, competition is only one of the many types of species interactions incorporated in the NRH under the umbrella term 'biotic interactions', which need to be considered when managing declined species.