New UBC drone footage gives insight into resident killer whale behaviour
Southern resident killer whale J31 and her three-month old calf J56 near the Fraser River in August, 2019. The calf was observed over two days carrying a fish in her mouth, even though calves only drink milk during their first year of life. (Andrew Trites/UBC photo)
VANCOUVER – Brand new drone footage coming out of the University of British Columbia is providing a rare glimpse into the underwater behaviours of resident killer whales off B.C.'s coast.
The footage, release Monday, was gathered in partnership with the Hakai Intitute and shows whales and their calves swimming and hunting together.
"In order to help these whales, we need to know more about them – how they hunt, how they forage and where their food is," said Andrew Trites, project lead and director of the Marine Mammal Research Unit at UBC's Institute for the Oceans and Fisheries in a news release.
"This is the first time drones have been used to study killer whale behaviour and their prey. It’s allowing us to be a fly on the wall and observe these animals undisturbed in their natural settings."
Drone footage was captured over three weeks in late August and early September. Over that time, researchers observed pods of northern and southern resident killer whales and their prey.
"We were very lucky with conditions the whole trip and came back with ten hours of footage," said Keith Holmes, drone pilot for the Hakai Institute. "Normally, we were flying between 100 and 200 feet above the whales, often higher. They didn't seem to notice the drone at all."
Some of the first images captured showed southern resident killer whales feeding on salmon in the Salish Sea between UBC and the Fraser River.
Other footage showed the northern resident killer whales in Johnstone Strait off Vancouver Island and off Calvert Island in the central B.C. coast.
"We observed a northern resident mother with her new calf," said Trites. "From the boat, we could tell they were swimming near each other. But it was only from the drone that we could see how much they were constantly touching and socializing with each other."
Unlike the southern resident whales, the population of northern killer whales has increased significantly since the 1970s.
"It was amazing to see the southern residents zig-zagging along the surface as they chased and caught Chinook salmon," said Sarah Fortune, a postdoctoral fellow at MMRU. "Observing both populations of killer whales means we'll be able to compare the foraging conditions and hunting behaviours of the two groups and see whether it is more difficult for southern residents to capture prey."
In the months ahead, the data will be used to better understand resident killer whales' feeding behaviour.
"I keep thinking back to the beauty of the mother and calf interacting with each other," Trites said. "It really drives home what's at stake for these whales if we don't figure out what's going on."