In March 2016, MUCRU researchers carried out a short pilot study along the Antarctic peninsula to measure the body condition of humpback whales (Megaptera novaeangliae). This study contributed to the broader research project of assessing body condition in baleen whales. Antarctica serves as the main feeding ground for Southern hemisphere humpback whales during the austral summer, and provided an opportunity to collect data for comparisons with that obtained from humpback whales in the Exmouth Gulf, Western Australia, in 2015. The expedition to Antarctica was carried out by Cheeseman’s Ecology Safaris, who kindly hosted two of our researchers onboard their ship the Ortelius.
After departing Ushuaia, Argentina, on the 10th of March, the Ortelius took two days to cross the Drake passage before reaching the Antarctic peninsula. For the next ten days, the Ortelius visited several feeding areas for humpback whales and other baleen whale species. From a zodiak, two Splashdrones, kindly donated by UAVwholesale Australia, were used to photograph humpback whales from the air, using both a still camera and a GoPro.
Results and implications
Over just five days, a total of 30 humpback whales were successfully photographed and measured. As expected, the whales measured in the Antarctic (feeding ground) were in a much better body condition than whales measured in Exmouth Gulf (breeding ground), as a result of them having spent nearly six months feeding on Antarctic krill (Euphausia superba). With a limited field effort, this study only provided a snapshot of the body condition of humpback whales on their feeding grounds. However, it gave a first valuable insight into the magnitude of difference in condition between humpbacks on their feeding and breeding grounds, and the amount of energy that humpback whales must accumulate to finance the costs of reproduction during the breeding season.
This research project was carried out under research permits from the Department of the Environment, Australia, the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), Australia, and with approval from the Murdoch University Animal Ethics Committee, Australia.