With the Belugas… Seen and Measured from the Sky!

By Alexandre Bernier-Graveline and Mathieu Marzelière

For GREMM’s research team, winter is usually synonymous with compiling, processing and analyzing images and data collected during an intense season on the water in the company of whales. Often in the shadows of the exciting field research conducted at sea, this office work or, as we like to call it, lab work, is essential for bringing the results of this research to light.

Since 2018, our field team has equipped itself with a new tool for filming belugas: the drone. This device is used not only to study their behaviour, but also to recognize them individually, only this time as seen from the sky. By combining this new approach with our legacy photo-identification program, which relies on views of the animals’ flanks, aerial photos will add new pages to the family album of St. Lawrence belugas.

This new technology allows us to obtain in a single image the complete portrait of belugas and thus recognize each animal as much from the left side as from the right. For example, Yogi, a female known since 1986, was recognizable mainly by the large mark on her left side resembling a bear paw, a shape to which she owes her nickname. Now, thanks to aerial photographs, the beluga family album has never been more complete. Now it’s even easier to recognize her!

This completely new perspective on the universe of belugas also allows us to measure them at the very moment they pierce the water surface. When working with an endangered species such as the beluga, we cannot capture and measure the animals for obvious reasons related to feasibility and ethics. Which means that, in the past, we were only able to measure stranded specimens. Yet an animal’s measurements, such as its length, width and girth reveal a wealth of information. These data could ultimately help us determine the sex of the animals, the reproductive status of females as well as the state of the belugas’ energy reserves hidden beneath their portliness. It is widely accepted that once it reaches adulthood, an animal’s weight can vary, especially at certain moments such as during illness, pregnancy or severe undernourishment.

To conduct these studies, known as photogrammetric analyses, one must first examine all of the video footage and photos collected by the drone. Whenever a beluga is observed on the water surface and is clearly visible, an image is taken. Each animal is then given a nickname in reference to its appearance, as well as a number which is attributed every time it is seen thereafter. Here on this picture, it is DL9051.