Contrary to popular legend, including the film Jaws, great white sharks aren’t solitary hunters after all. When the apex predators catch a dead whale’s scent, they converge on the buffet.
Scientists witnessed this unexpected behavior in South Africa’s False Bay, where four whales died of natural causes over the course of a decade. In winter, great whites hunt the 60,000 Cape fur seals foraging around an island rookery there. But when a whale dies, the seals get a break while up to 40 sharks a day devour the behemoth instead.
“White sharks are known as these killing machines, but they probably depend a lot on scavenging, especially as they get older,” says Neil Hammerschlag, a University of Miami marine ecologist and coauthor of the study, published in PLOS ONE.
During one episode, as seven great whites simultaneously tore blubber from a Bryde’s whale, one was so intent on the fatty meal that it chomped down on its neighbor’s head, leaving two teeth behind. Unfazed, both sharks kept eating.
Researchers watching from a boat noted that sharks are picky eaters, mouthing the carcass before settling on a specific spot to attack. What’s more, there’s a pecking order: The largest predators, which can exceed 15 feet, dominate blubber-rich areas.
Still, the oldest, biggest sharks are rarely seen in the bay (they may be too large to catch fast-swimming seals) except when a dead whale lures them in for a shared meal. The event may also provide an opportunity to meet potential mates.
After the sharks are finished eating and the carcass sinks to the seafloor, a bevy of creatures, from crabs to microscopic worms, feast on the leftovers.
This story originally ran in the September-October 2013 issue as "Stuffed to the Gills."