Murdoch University Cetacean Research Unit researcher Dr Fredrik Christiansen, in collaboration with Prof Lars Bejder, is developing a research project to improve our understanding of baleen whale body condition and reproduction by using novel non-invasive technology.
The study, funded by Murdoch University, involves using an Unmanned Aerial Vehicle (UAV) to measure seasonal changes in body condition of free-living humpback whales in the Exmouth Gulf, Western Australia and its influence on calf growth and condition.
“Little is known about the link between body condition and reproduction in large whales, which makes it difficult to monitor the health of baleen whale populations,” said Dr Christiansen.
Baleen whales are some of the largest mammals on earth including the blue, minke, right and humpback whale species. Dr Christiansen says that current practices for measuring these whales were not suitable for vulnerable populations.
“Methods to assess body condition in free-living whales are scarce so there is a need to develop and test new methods to measure body condition in large whales to assess the health of baleen whale populations globally.” he said.
“This study looks at the feasibility of using UAVs to take aerial shots of whales, from which body condition can be assessed.”
The 50 cm UAV is released from a small support boat within 100-200 m of the whales and is armed with cameras capturing still images and high definition videos. The vision is fed to a live link viewed by Dr Christiansen to ensure the UAV is positioned correctly. The drone hovers 20-30m above the whale to allow for an accurate measure of the size of the whales, which is then converted to a measure of relative body condition.
The method of using the highly complex UAV to measure humpback whales has never been done before on this particular baleen whale population.
The study will target females with calves that enter Exmouth Gulf during August through to October. The sheltered bay serves as an important resting and nursing ground for the whales during their southern migration back from their breeding grounds in the Kimberley. On a good day five or more mother and calf pairs can be measured, with the aim of having 200 animals measured at the end of the two month research project.
“We want to see how the body condition of the females relates to that of the calves. So if the females are in poor body condition, are they having calves that are also of poor body condition? That is what we are particularly interested in finding out,” continued Dr Christiansen.
The ability to monitor the body condition of the humpback whale population is extremely valuable, as it allows researchers to make global comparisons between baleen whale populations.
“In the future we can compare the west coast of Australia to the east coast and also to other populations globally. You can also look at the body condition of whales over time in relation to productivity in Antarctica, their feeding ground,” Dr Christiansen said.
This research project is done in collaboration with Lyn Irvine from the University of Tasmania and is carried out under a research permit from the Department of Parks and Wildlife and an Animal Ethics permit from Murdoch University. The UAV is operated under a UAV Operator Certificate and a Remotely Piloted Aircraft System License in accordance with Australian Civil Aviation Safety Authority regulations.
Want more information on the research project? Click HERE.