Is Climate Change Making Gray Whales Picky Eaters?

The Oregon Coast is known for its ruggedness and harsh weather, but also offers a prime opportunity to spot gray whales on their migratory paths. These majestic marine mammals undertake one of the largest migrations of any animal, traveling from the Arctic to Baja California to breed before heading back north along this “whale super-highway.” Despite having the mechanisms to feed in the water column, these benthic specialists prefer bottom feeding, scooping up sand from the seafloor and filtering out invertebrate prey through their baleen, likely targeting locations of high caloric content. However, along the coast of the Pacific Northwest, a behavior known as ‘prey switching’ has been observed, where gray whales feed in the water column instead of their preferred benthic prey, amphipods. Our upcoming guest, Taylor Azizeh, a first-year Ph.D. student at the Marine Mammal Institute, explores what may be driving this prey switching behavior.

Polar regions are among the top locations to be impacted by climate change, which Taylor suspects may be responsible for grey whales switching from benthic to pelagic prey. Changes in bottom water temperature and sediment grain size may result in habitats less favorable for amphipods, leading whales to seek food elsewhere. In response to warming, the distribution of other predators may shift to where they compete for the same food source, or the reduced sea ice cover could result in more productive pelagic waters. How do gray whales, these benthic specialists, adapt to changing food availability?

Gray whale populations often experience boom and bust cycles or unknown mortality events, with the most recent one currently underway. Taylor’s research on the foraging plasticity of gray whales is not only timely, but also employs a holistic approach using a combination of methods to assess the big picture. She plans to use stable isotopes to provide information on what whales are feeding on, but only when combined with GPS tags tracking movement and drone photogrammetry measuring body conditions can one understand where and why. Taylor plans to utilize this combination to ask big picture questions such as whether they’re feeding in areas of high biomass, if they return to those same areas, and how much adaptability can individual gray whales display?

At its core, Taylor’s research delves into the adaptability of gray whales. Gray whales have survived the ice ages, proving their ability to deal with harsh conditions, and Taylor hypothesizes they may be more flexible than we currently understand.

To learn more about Taylor’s passion for these charismatic animals of ecological, social, and cultural importance, the adventure which led here to grad school—from Costa Rica to Ecuador, Denmark, and London—tune in to KBVR 88.7 FM this Sunday, Nov. 3. You can listen to the episode anywhere you listen to your podcasts, including on KBVRSpotifyApple, or anywhere else!

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