Predator-induced collapse of niche structure and species coexistence
Document Type
Article
Date of Original Version
6-6-2019
Abstract
Biological invasions are both a pressing environmental challenge and an opportunity to investigate fundamental ecological processes, such as the role of top predators in regulating biodiversity and food-web structure. In whole-ecosystem manipulations of small Caribbean islands on which brown anole lizards (Anolis sagrei) were the native top predator, we experimentally staged invasions by competitors (green anoles, Anolis smaragdinus) and/or new top predators (curly-tailed lizards, Leiocephalus carinatus). We show that curly-tailed lizards destabilized the coexistence of competing prey species, contrary to the classic idea of keystone predation. Fear-driven avoidance of predators collapsed the spatial and dietary niche structure that otherwise stabilized coexistence, which intensified interspecific competition within predator-free refuges and contributed to the extinction of green-anole populations on two islands. Moreover, whereas adding either green anoles or curly-tailed lizards lengthened food chains on the islands, adding both species reversed this effect—in part because the apex predators were trophic omnivores. Our results underscore the importance of top-down control in ecological communities, but show that its outcomes depend on prey behaviour, spatial structure, and omnivory. Diversity-enhancing effects of top predators cannot be assumed, and non-consumptive effects of predation risk may be a widespread constraint on species coexistence.
Publication Title, e.g., Journal
Nature
Volume
570
Issue
7759
Citation/Publisher Attribution
Pringle, Robert M., Tyler R. Kartzinel, Todd M. Palmer, Timothy J. Thurman, Kena Fox-Dobbs, Charles C. Xu, Matthew C. Hutchinson, Tyler C. Coverdale, Joshua H. Daskin, Dominic A. Evangelista, Kiyoko M. Gotanda, Naomi A. Man in ’t Veld, Johanna A. Wegener, Jason J. Kolbe, Thomas W. Schoener, David A. Spiller, Jonathan B. Losos, and Rowan D. Barrett. "Predator-induced collapse of niche structure and species coexistence." Nature 570, 7759 (2019): 58-64. doi: 10.1038/s41586-019-1264-6.