Many sharks hunt small, plentiful prey. Great hammerheads take a different approach: Eat other sharks.
It's an energy-intensive strategy, but one that pays off for this critically endangered species, according to Institute of Environment research. As part of her Ph.D. research, Erin Spencer — working alongside world-renowned FIU shark ecologist Yannis Papastamatiou — tagged great hammerheads off Florida's coast with special trackers equipped with video cameras, as well as speed and sonar sensors.
The data helped build computer models comparing the energetic costs and rewards of different prey. The findings, published in Oecologia, were striking: When food is scarce, catching a single 55-pound blacktip shark about every three weeks can sustain a 250-pound hammerhead for up to two months.
