Records of Fatal Killer Whale (Orcinus orca) Attacks on Fin Whales (Balaenoptera physalus) with an Emphasis on Baja California, Mexico

Historically, there has been only one documented fatal killer whale (Orcinus orca) attack on a fin whale (Balaenoptera physalus)—from Baja California, Mexico (BC), in 2005. We compiled records of seven more recent fatal attacks, including four more from BC. Two male killer whales that we identified were involved, separately or together, in at least four of the five fin whale kills off BC as they traveled with their groups the length of the Baja Peninsula on both sides. They were also involved in two Bryde’s whale (Balaenoptera edeni) kills, and we suggest that they might specialize on large whale prey. We discuss offensive and defensive strategies during these attacks and the role (or lack thereof) of adult male killer whales. One of the fin whales taken appeared to be a healthy adult, which raises questions about large whales as prey for killer whales. We also discuss the burgeoning role of citizen science in this type of research, noting that most of our data came from social media postings.