On Prince of Wales Island in Alaska, gray wolves have begun hunting sea otters, a behavior that scientists are racing to understand. Led by University of Rhode Island Ph.D. candidate Patrick Bailey, the research explores how these predators capture marine prey and the broader ecological implications. This shift could link land and ocean food webs in unexpected ways.
Gray wolves, renowned for shaping terrestrial ecosystems, are now venturing into marine territories on Prince of Wales Island, Alaska. There, they prey on sea otters, an endangered species recovering from historical fur trade decimation. This unusual hunting pattern, documented for over two decades but poorly understood, prompts questions about adaptation and ecosystem connectivity.
Patrick Bailey, a Ph.D. candidate at the University of Rhode Island's Department of Natural Resources Science, heads the investigation. Collaborating with Sarah Kienle's CEAL Lab, he employs stable-isotope analysis on wolf teeth from museum collections and deceased animals. These teeth, layered like tree rings, reveal dietary histories. "If large enough, we can individually sample each of these growth rings to track an individual's feeding patterns over time," Bailey explains. By aggregating samples, the team assesses population-wide trends in marine reliance.
Trail cameras, installed by Bailey last summer, capture detailed footage. A team of seven URI students reviews more than 250,000 images collected since December, aiming to document capture techniques. "So far, we know that these wolves are consuming sea otters, and we're now staged to capture the details that have previously eluded us," Bailey notes. The island's remote, rugged terrain complicates fieldwork, but partnerships with Alaska Department of Fish and Game biologist Gretchen Roffler and technician Michael Kampnich provide crucial local insights. "This project would not be possible without their input and guidance," Bailey emphasizes.
Marine hunting poses unique challenges. "Capturing and eating prey in the marine environment is very different from doing it on land," says Kienle. Bailey suspects stronger land-sea food web links than previously recognized: "We don't have a clear understanding of the connections between water and land food webs, but we suspect that they are much more prevalent than previously understood."
A concerning side effect emerges from Roffler's work: sea otters accumulate high methylmercury levels, leading to elevated concentrations in coastal wolves—up to 278 times higher than in inland ones. "Methylmercury accumulation can cause a suite of problems related to reproduction, body condition, and behavioral abnormalities," Bailey warns. The study, focused on Alaska, plans eastward expansion, including skull morphology comparisons from Canadian specimens. Fieldwork continues for several years.