How do you lift a whale? The question has been asked by many researchers for generations. Better yet: How do you weigh a whale? Even better: Why would you weigh one? Danish scientists from the Aarhus Institute of Advanced Studies (AIAS), along with U.S. scientists from Woods Hole Oceanographic Institution (WHOI), thought it was time those questions were answered. And as it turns out, the answers may be found — like many in the environment — through the use of drones. Accurately measuring the weight of whales has always been a challenge, but drones and their imaging systems are taking it on. Courtesy of Fredrik Christiansen/ the Aarhus Institute of Advanced Studies. Whale scientists — they’re called cetologists, by the way — have tried to capture weight measurements before, but their only samples (patients?) were beached whales. The ones in the ocean proved to be too challenging to measure. They are, after all, very large, very slippery, and very aquatic. And the cetologists were skeptical about whether these measurements were even helpful because beached whales are usually either too bloated or too deflated for accurate analysis. In a recent study funded by the National Geographic Society, researchers focused on a specific part of the world and on a specific whale to conduct physical checkup experiments. They focused off the coast of Península Valdés in Argentina, deep in the clear waters where the southern right whale dwells. And the drones took to the skies. Aerial photos from the drones were taken of 86 whales and inserted into a computer model to take the measurements and convert them to weight. But why? “Knowing the body mass of free-living whales opens up new avenues of research,” said Fredrik Christiansen, lead author of the study and assistant professor at AIAS. “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.” (To be clear, he was still talking about the whales.) Another benefit to the study is learning how much prey the whales typically need, information that would provide further insight into the local ecology. One of Christiansen’s co-authors, Michael Moore, a biologist from WHOI, noted that weight measurements will give accurate calculations for life expectancy. “Weight measurements of live whales at sea can inform how chronic stressors affect their survival and ability to produce offspring,” Moore said. With the researchers’ success in measuring southern right whales, they are pondering what other mammals they could finally measure. They may even consider blue whales, which are way too big for the average bathroom scale. Christiansen said the new method will help advance future studies in ecology, physiology, and bioenergetics — making it possible “to finally include this central variable into future studies of free-living whales.” Another wave of success for drones, and whales.