Odhadovaný počet goril (A) a šimpanzů (B) na kilometr čtvereční v Kongu a Gabunu (S.Strindberg et al., Guns, germs, and trees determine density and distribution of gorillas and chimpanzees in Western Equatorial Africa, Science Advances 25 Apr 2018: Vol. 4, no. 4, eaar2964, DOI: 10.1126/sciadv.aar2964).