Being able to measure a killer whale’s girth and observe its overall condition without disturbing the animal is an important advancement in orca research.
By running a small hexacopter, also known as a drone, at a safe level over all 81 Southern Resident killer whales last month, researchers came to the conclusion that most of the orcas were in a healthy condition. Seven whales were picked out for further observation, including a few suspected of being pregnant.
I was especially intrigued by the idea that researchers could track the progress of a pregnancy. It has been long suspected that the first calf born to a young female orca often dies. A possible reason is that the calf receives a dangerous load of toxic chemicals from its mother. With this “offloading” of toxic chemicals from mother to first calf, later offspring receive lesser amounts of the chemicals.
Miscarriages and even births often go unnoticed, especially in the winter when the whales travel in the ocean far from human observation. If the young ones do not survive until their pod returns to Puget Sound, we may never know that a young whale was lost. Now, this remotely operated hexacopter may provide before and after pictures of a pregnant female, offering evidence when something goes wrong with a calf.
Images of the whales can be combined with skin biopsies and fecal samples collected by boat to provide a larger picture of the health of individual whales and the overall population.
Images of the whales collected this fall can be compared to those collected by conventional helicopter in 2008 and 2013 to assess any changes in the animals. Because of the noise and prop wash of a conventional helicopter, pilots must stay at a higher elevation to keep from disturbing the whales. There seems to be general agreement that drones are the way to go.
John Durban of NOAA Fisheries, who piloted the drone on 115 flights over the Southern Residents, said he was encouraged that their overall condition appeared better than in the past few years.
“Most individuals appear to be fairly robust this year, which is good news, but it’s also very important baseline information to have if the next few years turn out to be difficult for salmon and their predators,” Durban said in a news release.
Ken Balcomb of the Center for Whale Research has a somewhat different take on this new tool. The high rate of miscarriages and neonate deaths have long been known, Ken told me in an email. It is the only way that they are able to control their population within the carrying capacity of their food supply.
“I am more excited about five whales being born and surviving since last December than I am about an unproven morphometric surmise that additional whales are in some stage of a seventeen-month pregnancy,” he said. “It is not wise to ‘count your chickens before they hatch,’ as the saying goes.”
The goal should be to recover the population, Ken said. When it comes to recovering salmon and killer whales, resource management has been a dismal failure. His suggestion: Remove the Snake River dams and allow the salmon numbers to rebuild naturally while fixing Canada’s Fraser River.
“With climate change well underway,” Ken wrote, “we cannot fritter away golden opportunities to restore viability in what little is left of a natural world in the Pacific Northwest while counting unborn whales.”
Other aspects of this new effort involving the hexacopter were well covered by news reporters this week. Check out the list below. The new video with John Durban and NOAA’s science writer Rich Press can be seen above. Last month, I provided other information and links about the new tool. See Water Ways Sept. 9.
Recent news coverage:
- Drone photos show well-fed, healthy orcas, Tristan Baurick, Kitsap Sun
- Puget Sound’s killer whales looking good, Lynda Mapes, Seattle Times
- Researchers use drones to monitor killer whales as El Nino threatens food source, Yuliya Talmazan, Global News
- Vancouver Aquarium and U.S. agency team up for drone research of killer whales, Larry Pynn, Vancouver Sun
- Drone allows scientists to take detailed images of resident orcas, Kie Relyea, The Bellingham Herald