The role of science in understanding (and saving) large carnivores: A response to Allen and colleagues

Allen and colleagues contend that the study designs used to test for indirect effects of large carnivores on lower trophic levels are limited insomuch as they “rely on weak inference when valuing the roles of large carnivores in ecosystems.” Based upon their review of gray wolf and dingo studies, they conclude “that evidence for the ecological roles” (i.e., top-down effect) of these species is “equivocal.” Further, they assert that large carnivore science is being distorted in both the scientific and popular literature in order to justify restoration of large carnivores. They prescribe the use of manipulative experiments as the best means of understanding the effects of large carnivores on ecological systems, and systematic review of studies that “have used only manipulative experiments to investigate these hypotheses.” We take issue with Allen and colleagues' characterization of empirical evidence in the field of ecology, and we question the strength of evidence they present in support of prosecutorial assertions levied against scientists and science communicators. Ultimately, justification for the restoration of large carnivores is provided by two scientific claims that are unperturbed by Allen and Colleagues critique (i.e., that large carnivores routinely have important impacts on ungulate abundance, and overabundant ungulate populations often adversely impact the structure and biodiversity of habitats).