Status and Ecological Effects of the World’s Largest Carnivores

Abstract

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the author's version of the work. It is posted here by permission of the American Association for the Advancement of Science for personal use, not for redistribution. The definitive version was published in Science, Vol. 343 (2014), doi:10.1126/science.1241484. The published article can be found at: http://www.sciencemag.org/.Large carnivores face serious threats and are experiencing massive declines in their populations\ud and geographic ranges around the world. We highlight how these threats have affected the\ud conservation status and ecological functioning of the 31 largest mammalian carnivores on\ud Earth. Consistent with theory, empirical studies increasingly show that large carnivores have\ud substantial effects on the structure and function of diverse ecosystems. Significant cascading\ud trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of\ud these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic\ud cascades on various taxa and processes include changes to bird, mammal, invertebrate, and\ud herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon\ud sequestration; modified stream morphology; and crop damage. Promoting tolerance and\ud coexistence with large carnivores is a crucial societal challenge that will ultimately determine\ud the fate of Earth’s largest carnivores and all that depends upon them, including humans