Considering a living whale floating in the sea looks like an impossible task. Scientists solved it with the help of drones.
Unlike terrestrials, even the most giant creatures like elephants, whales cannot be measured or weighed. Scientists have thus far obtained these data from dead individuals.
The whales’ measurements and weights are inaccurate. A dead animal changes, it inflates, then losing body fluids. Or only parts of it are measured and weighed, and the whole weight is estimated. They are one-off data, and there is no link to past and future measurements. Therefore, it’s not possible to compare data and monitor increments or even weight loss.
Drones Provide a View from Above
The best way to estimate the length of a whale floating in the sea is from a view above. Previously, scientists had to rely solely on the elevated deck of a ship or plane, but now drones allow a much better view. The condition is clear water and the choice of the right place where whales regularly gather in more significant numbers. Such a location is the Argentinian Península Valdés, where the southern right whales (Eubalaena australis) come to breed every winter.
Using drones, scientists photographed 86 individuals from the dorsal and lateral sides in clear, shallow water, as states ScienceDaily. They obtained their exact length, height, and width. Then they created a 3D model of this whale species. Data collected from whalers hunting whales for scientific purposes were used to calculate its weight. They weigh their catches and measure the circumference of their body at the widest point. These steps were enough to make an accurate estimate of the weight of a specific size.
The created 3D model represents the average whale weight. Real whales differ in proportions of muscle and fat, but this does not diminish the model’s significance. Now scientists need only enlarge or reduce the model to the size of the whale photographed and get an accurate estimate of its weight.
Drone photos allow scientists to see how individual animals grow and gain weight over the years, how stress factors and food availability affect their lives and reproduction. Calculating the weight of a whale entangled in fishing nets will allow determining the exact dose of sedative that will soothe it before rescue. Scientists hope that after modifying the model, this method can be used to estimate the weight of other large marine animals.
Source and credit: https://www.sciencedaily.com/releases/2019/10/191002075927.htm, pixabay.com