A research team led by University of Hawai’i at Manoa marine biologists has captured whale’s-point-of-view and aerial drone video of humpback whale bubble-net feeding in the waters off of Southeast Alaska.
About 3,000 humpback whales (Megaptera novaeangliae) visit Alaska during the summer feeding period, and up to 10,000 visit Hawai’i during the winter breeding period.
When the whales leave their foraging grounds and migrate 3,000 miles, they stop eating until their return several months later.
“The footage is rather groundbreaking,” said Professor Lars Bejder, Director of the University of Hawai’i at Manoa Marine Mammal Research Program.
“We’re observing how these animals are manipulating their prey and preparing the prey for capture.”
“So it is allowing us to gain new insights that really haven’t been able to do before.”
Humpback whale bubble-net feeding. Image credit: University of Hawai’i at Manoa.
Professor Bejder and colleagues used suction-cup tags fitted with cameras and sensors to gain an understanding of how humpback whales feed and how some whales use bubbles to optimize their consumption of prey by creating bubble nets.
The tag data, coupled with the drone data, are providing novel insights into the fine-scale details of how the whales carry out this behavior and how often they do this to sustain and gain enough energy and weight before they migrate back down to Hawai’i to breed and mate.
“We have two angles and the drone’s perspective is showing us these bubble nets if you will and how the bubbles are starting to come to the surface and how the animals come up through the bubble net as they surface, while the cameras on the whales are telling us from the animal’s perspective, so overlaying these two data sets is quite exciting,” Professor Bejder said.
The observations are part of a larger project investigating causes of a possible decline in humpback whale numbers, including shifts in habitat use and changes to food availability linked to prey depletion and climate change.
