How do you weigh a living whale? The obvious response is very carefully, but scientists can’t exactly put these large marine mammals on a scale.
How do you weigh a living whale? The obvious response is very carefully, but scientists can’t exactly put these large marine mammals on a scale. Researchers from Aarhus Institute of Advanced Studies (AIAS) in Denmark and Woods Hole Oceanographic Institution (WHOI) in the U.S. devised a way to accurately estimate the weight of free-living whales using only aerial images taken by drones. The innovative method, published in the British Ecological Journal Methods in Ecology and Evolution, can be used to learn more about the physiology and ecology of whales.
By measuring the body length, width and height of free-living southern right whales photographed by drones, researchers were able to develop a model that accurately calculated the body volume and mass of the whales. Because of their large size and aquatic life, previously the only way to obtain data on the body mass of whales was to weigh dead or stranded individuals.
“Knowing the body mass of free-living whales opens up new avenues of research,” says Fredrik Christiansen, an assistant professor at AIAS and lead author of the study, which was funded by a research grant from the National Geographic Society. “We will now be able to look at the growth of known aged individuals to calculate their body mass increase over time and the energy requirements for growth. We will also be able to look at the daily energy requirements of whales and calculate how much prey they need to consume.”
Read more at Woods Hole Oceanographic Institution
Photo: A southern right whale surfaces in the clear waters off the coast of Península Valdés. Photo by Fredrik Christiansen, Aarhus Institute of Advanced Studies