Researchers from ETH Zurich, the Swiss Federal Research Institute WSL, and SPYGEN have joined forces to develop a groundbreaking flying device that can land on tree branches to collect ecological DNA (eDNA) samples. This innovative technology opens up new opportunities for biodiversity researchers and allows them to monitor species in previously understudied areas.

Ecologists increasingly rely on eDNA, the genetic material left by living organisms in the environment, to catalog and monitor biodiversity. While it is relatively easy to obtain samples from water or soil, other habitats like the forest canopy are difficult for researchers to access. The newly developed drone aims to solve this problem by autonomously approaching branches and remaining stable long enough to take samples using adhesive strips.

Equipped with a force sensor, the drone can measure the flexibility of branches on the spot and adjust its flight maneuver accordingly. The researchers tested their device on seven types of trees and found DNA from 21 separate groups of organisms, including birds, mammals, and insects.

Professor Stefano Minchev of ETH Zurich and WSL explains, "Landing on branches requires complex control. Initially, the drone does not know how flexible the branch is, so the researchers equipped it with a force sensor. This allows the drone to measure this factor on the spot and adapt its flight maneuver."

The researchers are now working to improve their drone for an upcoming competition in Singapore, where the goal is to spot as many different species as possible across 100 hectares of rainforest in 24 hours. To prepare for the event, they are testing the drone's performance in conditions similar to those it will operate in, such as the Masoala rainforest at the Zurich Zoo.

For the competition, the collection device must become more efficient and faster. In a test in Switzerland, the drone collected material from seven trees in three days, but in Singapore, it will need to sample many more trees in one day. Collecting samples in a natural rainforest poses an even greater challenge, as frequent rains wash eDNA off surfaces.

Minchev says, "We are very interested to see if our sampling method can prove itself in the extreme conditions of the tropics."

As the drone technology continues to advance, the potential for robot workers in the field of eDNA sampling becomes increasingly promising. Hire robots for eDNA sampling jobs and unlock new possibilities for biodiversity monitoring in previously inaccessible habitats.