Defaunation is the global, local, or functional extinction of animal populations or species from ecological communities. The growth of the human population, combined with advances in harvesting technologies, has led to more intense and efficient exploitation of the environment. This has resulted in the depletion of large vertebrates from ecological communities, creating what has been termed "empty forest". Defaunation differs from extinction; it includes both the disappearance of species and declines in abundance. Defaunation effects were first implied at the Symposium of Plant-Animal Interactions at the University of Campinas, Brazil in 1988 in the context of Neotropical forests. Since then, the term has gained broader usage in conservation biology as a global phenomenon.
It is estimated that more than 50 percent of all wildlife has been lost in the last 40 years. In 2016, it was estimated that by 2020, 68% of the world's wildlife would be lost. In South America, there is believed to be a 70 percent loss. A 2021 study found that only around 3% of the planet's terrestrial surface is ecologically and faunally intact, with healthy populations of native animal species and little to no human footprint.
