Green sloths and brown cows: the role of dominant mammalian herbivores in carbon emissions for tropical agro‐ecosystems

When Neotropical forests are cleared, there is a rapid switch in the dominant herbivore from wild sloths (suborder Folivora) to domestic cows Bos taurus. We quantified carbon dynamics for these mammals and the ecosystems they inhabit. Because of their low metabolic rates and photosynthetically‐active algae, sloths emit trivial amounts of carbon (12 g C/sloth*day) compared to cows (2.3 kg C/cow*day). In parallel, forests are carbon sinks (−242 g C/m2*year) and pastures sources (261 g C/m2*year); cows contribute >50% of the net emissions from pastures. For a small farm in Costa Rica, this turnover in herbivores translates into ~166 metric tonnes of additional C emitted annually.