Scientists are using drones to attach tracking tags to blue and fin whales, in a technique which might be more efficient and less disruptive to the marine mammals than conventional methods.

A paper published in Royal Society Open Science details the “first substantive investigation” by US researchers into using drones to attach biologging tags onto free-swimming whales.

Field trials in early 2022 using the drone method show it was successful in attaching tags in 21 out of 29 attempts. The average flight time from launch to tagging was 2.45 minutes, at an average distance of around 490 metres. 

Success was determined if the drone pilot or researcher observed the tag attaching to the animal and remaining secure during the whale’s subsequent dive.

The method could potentially enhance the study of cetaceans in the wild, the paper says.

Read more: How drones are changing the nature of marine science

Biologging tags help scientists collect information about marine mammals. These trackers attached to large, free-swimming whales by suction cup can provide insights into their ecology and human threats.

The conventional method of attaching tags involves researchers in small boats, closely approaching an animal (within metres), and reaching out with a pole to affix the tracker. Another method uses a pneumatic system to launch tags from up to 12m. 

The paper says, while conventional approaches are successfully used, they can be more challenging for fast moving species like fin and sei whales, and can pose potential disturbance and injury risk to both whales and people.

The speed, manoeuvrability and birds-eye-view provided by drones means the pilot can track the whale, even when it is travelling underwater,  “thereby maintaining an optimal position for tagging when the animal surfaces”.

During the trial, the reaction of the whales was minimal, the paper says.