In order to develop a conservation plan for a species, scientists need to know how many animals there are, where they are, and how they use the environment. The same data is needed when human changes to an environment take place so that the impact can first be anticipated, and then can be mitigated from the outset.

The introduction of offshore wind farms or the conversion of rainforest habitat to palm oil production can have major impacts on the animals that live there. The usual way to get this data was to put biologists’ boots on the ground – not so easy when the animal is nocturnal and cryptic, or lives most of its life underwater, or in extremely remote areas in challenging conditions.

Serge Wich, a conservation biologist and professor of primate biology at Liverpool John Moores University, was one of the first biologists to deploy drones in field research in 2011, and like most of the pioneers in the field, started by building the drones himself...