For decades, fish-eating killer whales in the Pacific Northwest have been observed harassing and even killing porpoises without consuming them—a perplexing behavior that has long intrigued scientists.
A study published today in Marine Mammal Science, co-led by Deborah Giles of Wild Orca and Sarah Teman of the SeaDoc Society, a program of the UC Davis School of Veterinary Medicine, looked at more than 60 years of recorded interactions between Southern Resident killer whales and porpoises in the Salish Sea to better understand why they exhibit this behavior.