Scientists in British Columbia say drone technology is giving them new insight into the health of the region’s beleaguered southern resident killer whale (SRKW) population.
Researchers with the Marine Mammal Research Unit (MMRU) at UBC’s Institute for the Oceans and Fisheries in partnership with the Hakai Institute spent three weeks in August and September monitoring pods of southern residents and their cousins, the northern resident killer whales.
Scientists are hoping to learn more about the hunting habits of the endangered SRKW population, which now numbers just 73 adults, by comparing them to the more robust northern group which numbers around 300 individuals.
Both groups primarily eat Chinook salmon, which is becoming increasingly scarce, and both face similar pressures such as noise pollution and increased shipping traffic.
“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 MMRU director.
“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.”
Researchers have also been collecting data on water temperature and salinity and tracking the local salmon population.
Project scientists will now spend the next several months poring over data to try and build a fuller picture of resident orca feeding behaviour.
The southern residents were observed in the area between UBC and the Fraser River, while the northern residents were recorded in the Johnstone Strait on the northeast coast of Vancouver Island and off Calvert Island on the central coast.
The team observing them kept the drones about 30-60 metres above the water, and said the whales appeared not to have noticed them.
Researchers say they saw the SRKW’s two nearly year-old calves, members of J-pod and L-pod, both of whom appeared to be doing well.
Scientists say the J-pod calf is female, which is good news in terms of hopes for re-population among the group.
Concern for the southern resident population has been growing in recent years, amid a string of unsuccessful calf births and the loss of several adults.
Three SRKWs died over the summer months, after displaying signs of malnutrition for months.
Researchers say there are many potential causes for the endangered population’s decline but that a lack of Chinook salmon — their primary source of food — is of particular concern.