Right whales forage near the water's surface at night, putting them at greater risk of potentially fatal collisions with boats, Jay Kirkham at Dalhousie University, Canada, and colleagues report on September 16, 2026, in the open access journal PLOS One.
Critically endangered North Atlantic right whales (Eubalaena glacialis) are threatened by human activities, such as fishing and shipping. During the summer, they forage in the coastal waters of the eastern United States and Canada, using specialized plates in their mouths to sieve plankton from the water. Conservation measures, such as vessel exclusion zones, where motorized boats are prohibited, have been implemented to protect whales. However, climate change is altering the availability and distribution of their zooplankton prey, which may drive the whales away from protected areas. Most whales forage at depth, so researchers can't directly observe them feeding. GPS tags have provided important insights into this unseen behavior, but accurately interpreting this data is challenging.
To address this problem, researchers attached special trackers to 23 North Atlantic right whales in the Gulf of St. Lawrence off the coast of Canada. The trackers were equipped with accelerometers, gyroscopes, magnetometers, depth recorders, underwater microphones, video cameras and light sensors, allowing the researchers to determine the body position, movement and behavior of the whales as they swam. They used the camera footage and tracking data to train machine learning models to identify movement patterns associated with feeding behavior.
The best-performing machine learning model agreed with the researchers' manual identification of feeding behavior 95% of the time. The data revealed that North Atlantic right whales spend between 11% and 76% of their time feeding, averaging 11.4 hours per day. During the day, whales fed close to the seafloor, but moved to the surface to forage at night, likely following the movements of zooplankton prey. This nighttime surface feeding had not previously been reported for North Atlantic right whales. The data showed that the whales spent around 25% of their time feeding outside of the vessel exclusion zone, putting them at risk of collisions with boats.
The study provides the first video footage of North Atlantic right whales feeding at the seafloor. It also reveals gaps in our understanding of their nighttime feeding behavior. Previously unreported surface foraging trips may have reduced the effectiveness of conservation protection measures, the authors say.
The authors add: "We deployed suction-cup attached biologging tags onto North Atlantic right whales, which record high resolution movement and video. Even though whales aren't always the best camera operators, we were able to analyze enough video to train machine learning algorithms how to identify periods of feeding. I think the most interesting thing that we found is that the whales switch their feeding behavior at night, feeding much closer to the ocean's surface, which could put them at a higher risk of collision with boats during the night. Being able to study one of the most endangered whales in the world is an amazing opportunity. We hope that by understanding more about the right whale we are able to contribute to their survival."
In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/4qWO7Mq
Citation: Kirkham J, Davies KT, Foley HJ, Zadra C, Frith R, Segre PS, et al. (2026) Open wide: Identifying North Atlantic right whale feeding behaviour using camera-validated kinematic data and machine learning. PLoS One 21(9): e0352346. https://doi.org/10.1371/journal.pone.0352346
Author countries: Canada, USA.
Funding: This research was funded by fisheries and oceans Canada via the Canada Nature Fund for Aquatic Species at Risk (CNFASAR) scheme (grant number 2021-10). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
