Peculiar's post about fishing for salmon in Nevada got me thinking about how skewed our baseline intuitions are regarding faunal populations. We are very poor at considering how abundant animal life was even three or four hundred years ago, let alone imagining back in deep time. We wildly underestimate what "normal" looks like.
On that subject, here's a charming paper which uses historical Chinese sources to estimate gibbon populations over a four hundred year span, before local extinction.
They (gibbons) appear in some of the Judge Dee stories, I believe as a deliberate attempt to give an air of authentic antiquity (the stories themselves being written over a millennium after that perspicacious gentleman's life). The Van Gulik novels are worth tracking down, being the work of a Dutchman writing English mysteries based on deliberately anachronistic Chinese stories of the eighteenth century written using Tang dynasty sources. Guardians against cultural appropriation can work out who owes what to whom.
I'm giving this a 'primates' label, optimistic that it will see heavy use.