Drone measurements reveal rapid early growth in eastern Australian humpback whales

Drone measurements reveal rapid early growth in eastern Australian humpback whales Sadie Harley Scientific Editor Andrew Zinin Chief Editor Eastern Australian humpback whales reach nearly their full adult size quickly, a new Griffith University–led study has found, as shown by the first contemporary growth curves for this recovering whale population. Published in Marine Mammal Science, the study combined drone-based aerial measurements with long-term photo-identification records to track growth across hundreds of whales ranging from newborn calves to adults more than 40 years old. The research, led by Griffith University Ph.D. candidate Stephanie Stack in collaboration with the Pacific Whale Foundation in Hervey Bay, found eastern Australian humpback whales reached approximately 10.9m (36 feet) in length by the age of five and attained 90% of their adult body length by about six to seven years of age. Stack said the findings suggested eastern Australian humpback whales grew faster than other humpback whale populations studied elsewhere in the world. "This is faster growth than other humpback whale populations that have been measured," she said. "These are also the first contemporary growth curves developed for eastern Australian humpback whales using measurements from living animals, updating knowledge that has relied heavily on measurements collected during the commercial whaling era in the mid-20th century. "These new growth curves establish a baseline for investigating how whale biology may respond to changing environmental conditions." Researchers collected measurements from 865 individually identified whales between 2021 and 2024 using noninvasive drone photogrammetry. The data set included calves, juveniles and adults, allowing growth during the important early years of life to be measured directly rather than inferred from older animals. The study found growth was most rapid during early life before gradually slowing as whales approached their maximum adult size. The new results aligned with historical estimates of adult body size from Australia, suggesting humpback whales have maintained similar adult lengths despite decades of population recovery and environmental change. Eastern Australian humpback whales are recognized as one of the world's most successful whale conservation stories, having recovered dramatically since the end of commercial whaling. "Understanding how quickly whales grow provides another piece of the puzzle in understanding the biology of this recovering population," Stack said. "Growth influences many aspects of a whale's life, including its health, energy requirements and potentially the timing of reproduction." Stack added the new growth curves provided an important benchmark for future monitoring of whale populations, and helped scientists investigate how humpbacks responded to changing ocean conditions. "As environmental conditions continue to change, having robust biological benchmarks like these will be essential for understanding how whale populations are responding," she said. Publication details S. H. Stack et al., Contemporary Growth Curves for Individual Humpback Whales in Eastern Australia Using Aerial Photogrammetry, Marine Mammal Science (2026). DOI: 10.1111/mms.70296 Journal information: Marine Mammal Science Provided by Griffith University