Researchers have developed a minimally invasive technique using uncrewed aerial vehicles (UAVs), or drones, to determine the sex and developmental stage of sperm whales in the wild. The study, conducted off the Galápagos Islands with 51 individuals, relies on photogrammetry to measure body lengths and other morphometric features from overhead images. These measurements are compared against historical whaling data on sperm whale growth curves and sexual dimorphism to assign developmental stages, such as calves, juveniles, subadults, or adults. A Bayesian statistical approach then estimates the probability that an individual is female based on body shape and size differences between sexes. The method achieved confident classifications for most whales examined. Additionally, the team analyzed peduncle diving behavior—a specific diving pattern—and found it aligns with prior observations: it is mainly performed by subadult males and directed toward females. This approach provides an efficient, low-cost alternative to traditional methods like genetic sampling or close vessel approaches, which can be disruptive. By enabling better demographic data collection on live sperm whales, the technique supports improved understanding of their social behavior, reproductive strategies, and population health. The findings contribute valuable insights for conservation efforts, especially for this culturally significant and vulnerable marine species. Datasets and scripts from the study are publicly available on GitHub for further research and validation.