Scientists use drone to study health of endangered orcas off B.C. coast
By Thandi Fletcher
After seeing the rich detail of an aerial photo capturing the tender moment of an orca mother nursing her calf off the British Columbia coast, biologist John Durban says he was blown away.
The stunning image is just one of thousands recently taken by a joint team of researchers at the Vancouver Aquarium and the U.S. National Oceanic and Atmospheric Administration, who are using a drone to take photos of the orcas in an effort to assess their body condition and health.
“It’s an incredible photograph,” NOAA biologist Durban told reporters at a news conference Wednesday to discuss the study’s findings. “It’s just a view we don’t get when you’re in the boat and you’re not close to the whale.”
The project marks the first time scientists have used a drone to take photos of the southern resident and northern resident orcas in order to measure their growth and determine which ones are healthy, malnourished or even pregnant.
Scientists have been keeping a keen eye on the southern resident orcas, which are listed as endangered under the Species at Risk Act. Southern residents prefer to eat Chinook salmon, as well as some other types of fish, but a reduction in the availability of prey has threatened the animals’ recovery.
After two record Chinook runs, however, aerial images of the orcas taken over the summer reveal promising news. The scientists found the southern resident orcas are not only robust but several appear to be pregnant.
Using the drone, the scientists also captured rare photos of the orcas feeding, nursing their calves, and sharing food with each other.
“This is really big,” said Lance Barrett-Lennard, head of the cetacean research program at the Vancouver Aquarium. “We knew a bit about this before we started the study, but from the air, we can clearly see whales catching fish, carrying them around for a little while and then handing them off to another killer whale.”
What Barrett-Lennard found striking about the photos was their ability to "make visual the social bonds between the whales."
"You see that they’re spending most of their time swimming so close together they can touch," he said. "They don’t have to do that. They can communicate over long distances. This is something that they want to do. It’s part of how they maintain social bonds."
To carry out the research, the scientists worked with engineers to build a custom drone, called a hexacopter, which uses six propellers that allow a high-resolution camera to remain stable and take crisp images. The scientists fly the drone for about 20 minutes at a time at a height of about 30 metres.
While scientists have taken aerial photos of orcas before using helicopters, the drone allows them to get a much closer look at the animals without disturbing them.
NOAA biologist Holly Fearnbach, who monitored a live video feed from the camera, said the whales didn’t appear to notice the drone.
“They never rolled over and looked up,” she said. “Even when we were quite lower than our normal altitude … we saw no response from the whales.”
Now that the scientists have established a baseline of the orcas’ health, they hope to use the drone to continue to monitor the animals for several years.
After months of unusually warm ocean temperatures combined with this winter’s El Nino, Barrett-Lennard said the team is anticipating poor returns for upcoming Chinook salmon runs, which they say will likely have a negative impact on the southern resident orcas.
“Southern residents … really need a very close eye,” he said. “We’ll watch them like a hawk and see what happens.”
Photo Credit: Jan Zeschky via Flickr