Drones offer new approach to whale research
DRONES ARE BEING used for the first time to gather information about the condition of humpback whales, allowing scientists to study them without disturbing them.
Researchers from Australian and Danish universities have been using the drones to capture videos and images of adult humpbacks and calves off the WA coast. Their research is being presented at the Australasian Wildlife Management Society conference in Perth this week.
Humpback whale numbers are bouncing back after depletion during the whaling era, and it’s unknown how the mammals will fair when the population inevitably peaks and stabilises.
“It will be interesting to see whether this has any impact on the condition of the animals… are the animals going to become thinner when there are more of them around? Or is it still going to remain a healthy population over time?” says Dr Fredrik Christiansen, a researcher from Murdoch University’s Cetacean Research Unit.
Drone footage of humpback whales in WA.
Monitoring the condition of humpback whales
Using photos taken from the drone and a fixed-wing aircraft, Fredrik and his colleagues have determined the length and width of 200 humpbacks over 44 days. In doing so, they’ve been able to track the animals’ weight loss during the calving season.
They found that adult females with calves experienced the most dramatic decline in condition, while juveniles and calves showed very little change.
“This difference in decline of body condition indicates that adults, in particular lactating females, are having much higher energetic costs than immature whales,” says Fredrik.
Drones a harmless, effective tool in humpback whale research
Every year, more than 20,000 humpback whales migrate north from their Antarctic feeding grounds to calve in warmer waters along the northern WA coastline, such as at Exmouth Gulf. The adult whales fast during the calving period, living off their fat supplies.
“Despite the fact that a lot of humpbacks got hunted in the last century, there was very little data actually collected from these hunts,” says Fredrik.
Lyn Irvine is a PhD candidate at the University of Tasmania, and has been working with Fredrik to photograph humpbacks and their newborns from a fixed-wing aircraft.
She says their project has demonstrated that photos can be a reliable means of gathering scientific data on humpbacks.
“It’s really important because it’s a non-invasive method of looking at body condition. Other methods around the world can be invasive and lethal,” says Lyn.