By listening in on belugas, scientists can better understand their social structure and their conservation needs

New research from the University of Windsor and Raincoast Conservation Foundation confirms that endangered St. Lawrence belugas show strong spatial structure, with important conservation implications.

Key insights from the research include:

Monitoring vocal signatures: By listening for the vocal signatures of belugas across a wide area and determining which signatures were heard where, the researchers examined whether different whales use different areas of the Estuary.
Beluga communities: Belugas tended to cluster in one of two areas, the Saguenay Fjord, and the south shore of the Estuary. These two groups were defined as the “Saguenay community” and the “South Shore community”.
Wandering whales: A small number of whales were found to travel widely; with one particular vocal signature re-detected at 5 of the 6 monitoring sites over the 5-year study. These well-travelled whales may be males, which are thought to range more widely than females.

Over five summers, a research team including Raincoast scientists collected acoustic recordings across the St. Lawrence Estuary in Québec, Canada. They were seeking to record belugas, and more specifically, their complex contact calls. These calls were of particular interest because they include a low-frequency signature element, a vocalization that is thought to denote individual identity or group membership, much like an acoustic name tag. By recording complex contact calls across the Estuary, the team hoped to determine whether different animals were occupying different areas.

The St. Lawrence Estuary is home to a geographically isolated, endangered beluga population that currently numbers only about a tenth of its historical population size. Despite decades of conservation effort and the establishment of a marine park, the St. Lawrence beluga population has shown little sign of recovery. For a long time, this population was considered to be relatively unstructured, with individuals ranging widely across the Estuary and using summering areas that were shared by the entire population.

A 2022 study by Bonnell et al. suggested that this may not be the case: by examining re-sighting records of photo-identified belugas, they found that individuals tended to be re-sighted in the same areas, year after year, suggesting the presence of population structure. To re-examine this hypothesis, the research team analyzed almost 6,000 hours of recordings collected over five summers, tracking which signature elements were heard where, and whether they tended to be re-heard in the same areas over time.

Their findings mirrored those of Bonnell et al.: based on re-detection of their signature elements, whales tended to remain clustered in one of two areas: the Saguenay Fjord, a narrow tributary of the St. Lawrence River, or the south shore of the Estuary. “We found that most whales tended to be loyal to a specific area,” said Dr. Aubin [Raincoast Conservation Foundation and University of Windsor]. “A few whales ranged much more widely, but they were a very small minority.”

Importantly, much of the South Shore community’s range falls outside of the current boundaries of the Saguenay-St. Lawrence Marine Park, meaning that it has historically received fewer legal protections than the Saguenay community. An expansion of the park was recently approved and confirmed by the provincial government but is awaiting federal confirmation. This expansion will be important in ensuring that both communities receive the protections needed to ensure population recovery.

“This isn’t just an academic distinction, it has real consequences for conservation. If we manage this population as one uniform group, we risk protecting one community while leaving another exposed,” said Dr. Vergara, Director of the Cetacean Conservation Research Program at Raincoast Conservation Foundation and Senior Author of the paper.

The paper, “From calls to communities: Acoustic monitoring of contact calls indicates spatial structure in endangered belugas” is published in Animal Behaviour.

Citation

Aubin JA, Mennill DJ, Mikus M-A, Michaud R, Vergara V. 2026. From calls to communities: acoustic monitoring of contact calls indicates spatial structure in endangered belugas. Animal Behaviour.:123662. doi:10.1016/j.anbehav.2026.123662.

Abstract

Animal populations often exhibit complex patterns of spatial or social structure, with various levels of organization below the population level. Acoustic monitoring can reveal such structure, particularly when animals produce calls that contain individual or group-level signatures. In this study, we monitored the complex contact calls of belugas, Delphinapterus leucas, in the St Lawrence Estuary, Canada, across six sites during five field seasons. Using a mark–recapture-based movement network, we examined the movement of belugas by tracking the occurrence of distinctive contact calls across sites. Our movement network revealed a high degree of population structure and the presence of two distinct communities: one within the Saguenay Fjord, recorded at two locations (i.e. the ‘Saguenay community’), and another along the southern shore of the estuary, recorded at four locations (i.e. the ‘South Shore community’). These results align with findings of a previous photo-identification-based study that suggested the presence of clusters of individuals inhabiting the Saguenay Fjord and southern shore of the estuary. Our study provides the first acoustic evidence of fine-scale population structure in the endangered St Lawrence Estuary beluga population. These findings, together with the population’s exposure to significant anthropogenic disturbances across its range, reinforce the need to expand the Saguenay–St Lawrence Marine Park to protect the core habitats and home ranges of both communities. More broadly, our results demonstrate that passive acoustic monitoring can reveal population spatial structure and inform behaviour-driven conservation action.