The other day Alexis Manning posted a link in the Nat Geo Daily 10 to a video showing rare footage of a pod of orcas attacking a family of sperm whales (watch above). The video is from Blue Sphere Media, a production company with the tagline: “We fuse dramatic imagery with intimate and thought-provoking stories, to connect people to globally important issues and inspire action.”
Blue Sphere Media founder Shawn Heinrichs posted on his website that his team caught the footage on a nine-day trip to Sri Lanka, where they were looking for blue whales. Heinrichs wrote: “Together we battled rough seas, burning sun, cramped boat conditions, and long days searching endless seas. Though not so successful with blue whales, what we did achieve was beyond anything any of us could have imagined, as we documented a world first underwater!”
The group captured the action on a Canon 1DX in Nauticam Housing and a GoPro 3.
While the video is exciting, it’s clear Heinrichs is reading from a script, and the narration is peppered with dramatic language (“dorsal fins slicing through the water,” etc.), so the whole thing came off as a little breathless to me. I wondered how rare the attack really was.
So I reached out to National Geographic grantee Robert L. Pitman, a scientist in the Marine Mammal & Turtle Division of the Southwest Fisheries Science Center in the National Marine Fisheries Service. Pitman is based in La Jolla, California, though he emailed us from the field in Cambodia.
Pitman studies killer whale predation, and co-authored a paper in Marine Mammal Science in 2001 called “Killer Whale Predation on Sperm Whales: Observations and Implications.” Pitman also co-wrote a piece in Natural History called “Terror in Black and White” in 1998, which documented orca attacks on a pod of sperm whales off the coast of California.
Pitman told us:
I did see the video and it is quite astonishing. I have spent many years at sea studying whales and dolphins, and killer whales in particular, and I have only seen this behavior once (see the above links). It has rarely been observed and never before filmed so I was quite interested in seeing the available footage. This is about the largest predatory event you can witness on our planet – the largest apex predator taking on one of the largest prey species. Truly a battle of titans.
But, despite the huge size advantage that sperm whales have, and their massive jaws that hold the largest set of teeth in the world, sperm whales are terrified in the presence of killer whales. However, their enormous size does make them a formidable and potentially dangerous prey for killer whales, which may be why attacks are recorded so infrequently: there may be relatively few groups of killer whales that have learned how to safely and effectively prey on sperm whales.
When sperm whales are attacked they often form a rosette, a wagon-wheel formation with their heads pointed in and their tails pointed out. When they are in this formation, they flail the water with their massive tails in an effort to ward off the attackers. If there is a calf present, the killer whales will focus their attack on it, so the sperm whales will put the calf in the middle of the rosette to keep the killer whales from harming it. The killer whales must be very careful around agitated sperm whales because a slap from that tail could be life-threatening.
I think that killer whales attacking sperm whales is perhaps the most spectacular animal interaction that occurs on Earth today, and perhaps hasn’t seen its equal since dinosaurs roamed the Earth 65 million years ago. Just incredible!!
Another National Geographic grantee, Filipa Samarra, told us, “I am not an expert on this particular region, but it seems to me like a very interesting encounter. As far as I know this type of attack on sperm whales specifically is little recorded with such high quality video, but it is known that killer whales may attack sperm whales. This type of behaviour where the group of orcas tries to separate a single, usually young individual, is also known from their attacks on other whales, like grey whales off the California coast.”
Samarra, who studies killer whale social and foraging behavior in Iceland, added that little is known about the whales off Sri Lanka.
Brian Clark Howard covers the environment for National Geographic. He previously served as an editor for TheDailyGreen.com and E/The Environmental Magazine, and has written for Popular Science, TheAtlantic.com, FastCompany.com, PopularMechanics.com, Yahoo!, MSN, and elsewhere. He is the co-author of six books, including Geothermal HVAC, Green Lighting, Build Your Own Small Wind Power System, and Rock Your Ugly Christmas Sweater.