Whales are swimming farther than previously estimated—up to 20% more—according to a study published in the journal Ecology.
Co-authored by Olaf Meynecke, from Griffith University, the study reveals that traditional methods of calculating animal movement may drastically underestimate the actual distance traveled, particularly in marine species such as whales.
“For years, we tracked whales using satellite tags, tracing their movements across the oceans,” Meynecke says.
“But this research shows that we were only seeing part of the picture,” he warns.
The study, led by a multidisciplinary team of global researchers from the University of Connecticut, the Smithsonian Institution, and the Pontificia Universidad del Ecuador, reinforces the notion that animal movement is not limited to flat maps.
Marine animals, such as whales, move in three dimensions: along the surface and up and down through the water column.
By integrating geodesy (the science of the shape of the Earth) with animal tracking data, the researchers revealed that the curvature of the Earth and diving behavior significantly increase the total distance traveled.
Using satellite data from the longest continuous tracking of humpback whales by the Whales and Climate Program, from Ecuador to near Antarctica, the team compared two distance measurement methods: a standard surface tracking of approximately 6,658 kilometers and a revised 3D geodesic estimate that took into account depths and average diving speeds.
The result was an additional distance of 1,055 kilometers, or about 16% more.
“For humpback whales that migrate between breeding areas in South America and feeding areas in Antarctica, this could mean traveling up to 14,000 kilometers in a single migration season,” Meynecke says.
“That is seven times greater than the average number of journeys a human makes in a year,” he adds.
“These findings are more than fascinating; they have real implications for how we understand the energetic demands and the ecological pressures on migratory species,” he explains further.
“If animals are spending more energy than previously estimated, we may be underestimating the ecological costs of migration and the impacts of environmental changes,” he warns.
