A ‘mystery monkey’ in Borneo may be a rare hybrid. That has scientists worried

Habitat fragmentation may have driven two primate species to mate that wouldn’t have otherwise

Two monkeys standing on a tree branch; a juvenile monkey is being groomed by a female silvered-leaf monkey

This juvenile monkey being groomed by an adult female silvered leaf monkey may be a rare hybrid, born after possibly that female mated with a male proboscis monkey.

Ken S.H. Ching

Six years ago, tour guide Brenden Miles was traveling down the Kinabatangan River in the Malaysian part of Borneo, when he spotted an odd-looking primate he had never seen before.