Zhifei Zeng ’23
The size of wild animals is closely related to body condition. For example, the size of whales usually reflects changes in their fat stores and thus their body condition. However, it is difficult for scientists to directly measure the body size of whales due to their large size and ocean environment. Therefore, a research group led by Dr. Lesley H. Thorne at Stony Brook University developed a 3D modeling technique, which they combined with unoccupied aerial vehicle photography, to represent the body size of whales.
The researchers used humpback whale morphometric data as a case study. First, they collected morphometric data on humpback whales using drones in New York Bay and Australia, respectively. Then, they built 3D models of humpback whales on a software called Blender- they placed the back and side images vertically and added a cylinder scaled to the length and height of the whales. They also scaled the model to consider the difference in the size of the humpback whale from region to region and from age to age. At the same time, the whale model was calculated the difference in volume of each section of the body between adult and juvenile whales. By analyzing data from thousands of whale models, the researchers arrived at the best models for adult and juvenile whales.
Compared to traditional modeling approaches that require dozens of measurements to accurately represent the whale’s body size, this 3D modeling technique can use five width measurements to generate a whale body model, with an error rate of only 5 percent. This technology can assist in studies related to the body condition of large marine mammals by using data from different sources to examine the body shape of individual whales. Furthermore, by calculating the body size, the technology can also provide weight estimates to administer accurate sedative doses for stranded marine animal rescues.
 N. Hirtle, et al., Integrating 3D models with morphometric measurements to improve volumetric estimates in marine mammals. Methods in Ecology and Evolution 13, (2022). doi: 10.1111/2041-210X.13962
 Image retrieved from: https://get.pxhere.com/photo/water-ocean-splash-mammal-humpback-whale-fin-vertebrate-whale-marine-mammal-marine-biology-whales-dolphins-and-porpoises-grey-whale-63183.jpg