Tonkin snub-nosed monkeys are native to Vietnam, and most of them live in two forests in the north of the country.
A team working for wildlife charity Fauna & Flora have been doing a survey of the monkeys in one of these forests, Khau Ca Species and Habitat Conservation Area.
The survey took 10 days and involved the team using drones, cameras and binoculars to try and spot the creatures.
They even used a special bit of tech called an ‘audiomoth’, which can listen and recognise the calls of the monkeys.
The team even spotted three baby monkeys in two groups!