≤50 % of individual animals
||Ceballos G, Ehrlich PR, Dirzo R. Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines. Proc Natl Acad Sci U S A. 2017 Jul 25 114(30):E6089-E6096. doi: 10.1073/pnas.1704949114 p.E6095 left column bottom paragraphPubMed ID28696295
||P.E6095 left column bottom paragraph: "When public mention is made of the extinction crisis, it usually focuses on a few animal species (hundreds out of millions) known to have gone extinct, and projecting many more extinctions in the future. But a glance at [investigators'] maps presents a much more realistic picture: they suggest that as much as 50% of the number of animal individuals that once shared Earth with us are already gone, as are billions of populations."