New study documents California coyotes eating harbor seal pups

by Mark DeGraff, UC Santa Cruz
February 13, 2025

Whether it’s ice cream, a greasy hamburger, or a heap of french fries, everybody loves fatty foods. For coyotes, that meal is a blubbery seal pup, according to a new study led by UC Santa Cruz scientists.

A paper published on February 12 in the journal Ecology details how the researchers used motion-triggered cameras placed at MacKerricher State Beach, north of Fort Bragg, during harbor seal pupping season in the spring of 2023 and 2024. Led by UC Santa Cruz Ph.D. student Frankie Gerraty, the team recorded three instances of a coyote dragging a baby harbor seal away from the beach and devouring it. 

The coyotes often ate the brain first, and removed the seals’ head to get to it. Scientists combing the sand dunes overlooking the rookery have found the bodies of over 50 pups hunted this way since 2016. “I had a hunch it was coyotes,” Gerraty said. “Terrestrial wildlife that eat seafood are a major focus of mine, and we know that coyotes are very adaptable.”

The mystery began when study co-author Sarah Grimes, of the Noyo Center for Marine Science, began noticing seal-pup carcasses that were dragged to the same spot and eaten. “There was consistency,” she said. “They weren’t scattered here and there.” 

Black bears, bobcats, and mountain lions all call the region home, so it was not immediately clear who was responsible. Tracks and droppings found nearby eventually led Grimes to suspect coyotes, but Gerraty secured proof when he captured them on video.

“I immediately told Sarah,” he said. “For six years, she had been building up so many ideas about what it could be and how it was happening.”

Keep reading: https://news.ucsc.edu/2025/02/coyotes-seal-pups.html

Read the Ecology paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.70031